Composite material forming thermal history design method and composite material component

Abstract

The embodiment of the application provides a composite material forming thermal history design method and a composite material component. It relates to the technical field of composite material forming manufacturing. The method comprises the following steps: obtaining characteristic parameters of the composite material component; constructing a heat transfer and solidification coupling model in the forming process of the composite material component based on the characteristic parameters, so as to predict the internal temperature evolution and solidification degree process of the material; determining a heat accumulation zone based on the heat transfer and solidification coupling model; designing an external heat input path and process parameters based on the heat accumulation zone; and adjusting the input path and the process parameters, so that the exothermic process of the composite material component when crossing the heat accumulation zone is changed from concentrated release to dispersed release. The quality of the prepared thick-walled composite material component can be improved.

Description

Technical Field

[0001] This invention relates to the field of composite material molding and manufacturing technology, and in particular to a method for designing the thermal history of composite material molding and a composite material component. Background Technology

[0002] Thermosetting composite materials are widely used in energy equipment, aerospace, oil and gas development, rail transportation, and pressure vessels. With the continuous improvement of application requirements, composite material components are gradually developing towards larger size, thicker walls, and higher performance. However, thick-walled thermosetting composite material components are more prone to internal heat accumulation during the curing process.

[0003] Currently, parameter optimization based on process experience and experimental feedback is commonly used to control the thermal buildup of thick-walled thermosetting composite components during curing. For example, in pultrusion, a suitable process window is found by repeatedly adjusting the mold temperature, temperature zone length, or traction speed; in autoclave or curing oven processes, the possibility of thermal runaway is reduced by adjusting the heating rate, holding time, and curing program. However, these methods may result in lower quality thick-walled composite components. Summary of the Invention

[0004] This application provides a method for designing the thermal history of composite material molding and a composite material component, which can improve the quality of the prepared thick-walled composite material component.

[0005] In a first aspect, embodiments of this application provide a method for designing the thermal history of composite material molding, including:

[0006] Obtain the characteristic parameters of composite material components;

[0007] Based on characteristic parameters, a heat transfer and curing coupling model is constructed in the molding process of composite material components to predict the internal temperature evolution and curing degree process of the material. The heat transfer and curing coupling model is used to indicate the relationship between curing heat release and material heat transfer.

[0008] Based on the heat transfer and curing coupling model, the heat accumulation zone is determined. The heat accumulation zone is used to indicate the area where the heat release of the reaction is concentrated during the curing process of composite material components, the heat is difficult to transfer outward, and the temperature rise and temperature peak are likely to occur.

[0009] Based on the heat accumulation zone, the input path and process parameters of external heat are designed. The process parameters are controllable parameters that regulate at least one of the following: the temperature change process of the composite component, the heating time, the relative motion state of the heat source, and the heat transfer boundary conditions.

[0010] By adjusting the input path and process parameters, the heat release process of composite material components crossing the heat accumulation zone can be changed from concentrated release to dispersed release.

[0011] In one possible implementation, the thermal accumulation zone is determined based on a heat transfer-solidification coupling model, including:

[0012] Based on the heat transfer and curing coupling model, the temperature field, degree of curing field and heat release information of composite material components are predicted during the curing process.

[0013] Based on temperature field, curing degree field and exothermic information, the heat accumulation zone during the curing process of composite material components is identified.

[0014] In one possible implementation, the characteristic parameters include one or more of the following: resin curing kinetic parameters, resin reaction exothermic parameters, effective thermal conductivity of the composite material, and product structural parameters.

[0015] In one possible implementation, the external heat input path includes a temperature path and a time path. The temperature path is used to indicate the overall temperature change of the composite component as the process progresses during molding, and the time path is used to indicate the duration change of the composite component in different heating zones and different process stages.

[0016] Temperature paths include heating, cooling, holding, or combinations thereof;

[0017] The time path includes dwell time, heat preservation time, material transit time, or a combination thereof.

[0018] In one possible implementation, the input path is achieved in at least one of the following ways:

[0019] Mold temperature zone control;

[0020] Autoclave heating program;

[0021] Curing oven heating program;

[0022] Heating platform temperature control;

[0023] Induction heating control;

[0024] Infrared heating control.

[0025] In one possible implementation, the process parameters include one or more of the following: temperature of each temperature zone, heating rate, holding time, total mold length, length of each temperature zone, component dwell time, and traction speed.

[0026] In one possible implementation, by adjusting the input path and process parameters, the heat release process of the composite component crossing the heat accumulation zone is changed from concentrated release to dispersed release, including:

[0027] Target ranges are set for the curing and molding parameters of composite material components. After adjusting the input path and process parameters, the actual values ​​of the curing and molding parameters of composite material components are calculated by the heat transfer and curing coupling model.

[0028] When the actual value meets the corresponding target range, it indicates that the input path and process parameters have been adjusted appropriately.

[0029] When the actual value does not meet the corresponding target range, the input path and process parameters are readjusted, and the actual value is recalculated and judged through the heat transfer and curing coupling model until the set target range is met.

[0030] In one possible implementation, the curing parameters include one or more of the following: the highest internal temperature of the composite component, the radial temperature difference between the inside and outside, the difference in curing degree between the inside and outside at the outlet, the degree of curing at the outlet, and the final degree of curing.

[0031] Secondly, embodiments of this application provide a composite material molding thermal history design device, comprising: an acquisition module, a construction module, a determination module, a design module, and an adjustment module, wherein...

[0032] The acquisition module is used to acquire the characteristic parameters of composite material components;

[0033] The module is used to build a heat transfer and curing coupling model for the molding process of composite components based on characteristic parameters, so as to predict the internal temperature evolution and curing degree process of the material. The heat transfer and curing coupling model is used to indicate the relationship between curing heat release and material heat transfer.

[0034] The determination module is used to identify the heat accumulation zone based on the heat transfer and curing coupling model. The heat accumulation zone is used to indicate the area where the heat release of the reaction is concentrated during the curing process of composite material components, the heat is difficult to transfer outward, and the temperature rise and temperature peak are likely to occur.

[0035] The design module is used to design the input path and process parameters of external heat based on the heat accumulation zone. The process parameters are controllable parameters that regulate at least one of the following: the temperature change process of the composite component, the heating time, the relative motion state of the heat source, and the heat transfer boundary conditions.

[0036] The adjustment module is used to change the heat release process of composite material components crossing the heat accumulation zone from concentrated release to dispersed release by adjusting the input path and process parameters.

[0037] In one possible implementation, the determining module is specifically used for:

[0038] Based on the heat transfer and curing coupling model, the temperature field, degree of curing field and heat release information of composite material components are predicted during the curing process.

[0039] Based on temperature field, curing degree field and exothermic information, the heat accumulation zone during the curing process of composite material components is identified.

[0040] In one possible implementation, the characteristic parameters include one or more of the following: resin curing kinetic parameters, resin reaction exothermic parameters, effective thermal conductivity of the composite material, and product structural parameters.

[0041] In one possible implementation, the external heat input path includes a temperature path and a time path. The temperature path is used to indicate the overall temperature change of the composite component as the process progresses during molding, and the time path is used to indicate the duration change of the composite component in different heating zones and different process stages.

[0042] Temperature paths include heating, cooling, holding, or combinations thereof;

[0043] The time path includes dwell time, heat preservation time, material transit time, or a combination thereof.

[0044] In one possible implementation, the input path is achieved in at least one of the following ways:

[0045] Mold temperature zone control;

[0046] Autoclave heating program;

[0047] Curing oven heating program;

[0048] Heating platform temperature control;

[0049] Induction heating control;

[0050] Infrared heating control.

[0051] In one possible implementation, the process parameters include one or more of the following: temperature of each temperature zone, heating rate, holding time, total mold length, length of each temperature zone, component dwell time, and traction speed.

[0052] In one possible implementation, the adjustment module is specifically used for:

[0053] Target ranges are set for the curing and molding parameters of composite material components. After adjusting the input path and process parameters, the actual values ​​of the curing and molding parameters of composite material components are calculated by the heat transfer and curing coupling model.

[0054] When the actual value meets the corresponding target range, it indicates that the input path and process parameters have been adjusted appropriately.

[0055] When the actual value does not meet the corresponding target range, the input path and process parameters are readjusted, and the actual value is recalculated and judged through the heat transfer and curing coupling model until the set target range is met.

[0056] In one possible implementation, the curing parameters include one or more of the following: the highest internal temperature of the composite component, the radial temperature difference between the inside and outside, the difference in curing degree between the inside and outside at the outlet, the degree of curing at the outlet, and the final degree of curing.

[0057] Thirdly, embodiments of this application provide an electronic device, including: a memory and a processor;

[0058] The memory stores instructions that the computer executes;

[0059] The processor executes computer execution instructions stored in memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0060] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible implementations of the first aspect.

[0061] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the first aspect and / or various possible implementations of the first aspect.

[0062] In a sixth aspect, embodiments of this application provide a chip, the chip including at least one processor, the processor being configured to execute program instructions to implement the first aspect and / or various possible implementations of the first aspect as described above.

[0063] In a seventh aspect, embodiments of this application provide a composite material component, which is made by the first aspect and / or various possible embodiments of the first aspect as described above.

[0064] Eighthly, embodiments of this application provide a composite material component molding system, the composite material component molding system including an external heat input unit and a control unit, the control unit being configured to perform the first aspect and / or various possible implementations of the first aspect above, to control the external heat input unit to apply external heat input to the composite material component; the external heat input unit includes one or more of a mold heating unit, an autoclave heating unit, a curing oven heating unit, a heating platform, an induction heating unit, and an infrared heating unit.

[0065] Ninthly, embodiments of this application provide a continuous molding apparatus, the continuous molding apparatus including a mold having a temperature zone structure for changing the heat release process of a composite material component across a heat accumulation zone from concentrated release to dispersed release.

[0066] The composite material molding thermal history design method and composite material component provided in this application construct a heat transfer and curing coupling model that can correlate curing heat release and material heat transfer by combining the characteristic parameters of the composite material component. This model accurately locates the heat accumulation area during the curing process and designs the external heat input path and matching process parameters accordingly. It breaks the traditional experience-based trial-and-error process optimization mode, and can achieve accurate prediction and active control of the curing heat release process of thick-walled composite materials. It transforms centralized heat release into decentralized heat release, thereby reducing the internal peak temperature, reducing the temperature difference, and improving the curing uniformity. This enables the stable manufacturing of thick-walled thermosetting composite material components and improves the quality of the prepared thick-walled composite material components. Attached Figure Description

[0067] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0068] Figure 1 A flowchart illustrating a composite material molding thermal history design method provided in this application embodiment;

[0069] Figure 2 A flowchart illustrating a method for adjusting input paths and process parameters provided in an embodiment of this application;

[0070] Figure 3 This is a schematic diagram of a temperature zone setting provided in an embodiment of this application;

[0071] Figure 4 A schematic diagram illustrating a reaction rate comparison provided in an embodiment of this application;

[0072] Figure 5 A schematic diagram illustrating a peak temperature comparison provided in an embodiment of this application;

[0073] Figure 6 A schematic diagram illustrating a radial internal and external temperature difference comparison provided in an embodiment of this application;

[0074] Figure 7 A schematic diagram illustrating the difference in curing degree between the inside and outside of the outlet, provided as an embodiment of this application;

[0075] Figure 8 A schematic diagram of a composite material molding thermal history design device provided in this application embodiment;

[0076] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0077] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0078] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0079] Furthermore, the technical solution involved in this application, which involves big data analysis of user information (including but not limited to personal biometrics, identity data, consumption data, asset data, electronic terminal operation data, etc.) and the use of artificial intelligence technology for automated decision-making, and makes decisions that have a significant impact on personal rights based on the results of automated decision-making, provides users with corresponding operation entry points for users to choose to agree to or reject the results of automated decision-making; if the user chooses to reject, the process will proceed to the expert decision-making process.

[0080] It should be noted that the composite material molding thermal history design method and composite material component provided in this application can be used in the field of composite material molding and manufacturing technology, and can also be used in fields other than the field of composite material molding and manufacturing technology. The application field of the composite material molding thermal history design method and composite material component in this application is not limited.

[0081] It should be noted that in the embodiments of this application, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, it does not mean that the applicant has used or necessarily used the solution.

[0082] Thermosetting composite materials, due to their advantages such as high specific strength, high specific modulus, corrosion resistance, and strong design flexibility, are widely used in energy equipment, aerospace, oil and gas development, rail transportation, and pressure vessels. With increasing application demands, composite material components are gradually developing towards larger sizes, thicker walls, and higher performance, such as continuous composite sucker rods, thick-walled wound pipes, composite pressure vessels, large prepreg laminate structures, and resin transfer molding (RTM) components. However, thick-walled thermosetting composite material components are more prone to internal heat accumulation during the curing process. On the one hand, the curing reaction of thermosetting resins releases a large amount of heat; on the other hand, the thermal conductivity of composite materials, especially in the thickness direction, is limited, making it difficult to dissipate the internal heat in a timely manner. When the component size increases to a certain extent, a significant imbalance occurs between the internal heat release process and the heat diffusion process, leading to a rapid increase in internal temperature, even exceeding the external heating temperature.

[0083] Among them, thermal accumulation can manifest as: excessively high internal temperature peaks, uneven temperature distribution in the cross-sectional direction, asynchronous internal and external curing, local over-curing, increased residual stress, and defects such as cracking, delamination, and splitting, which can affect the manufacturing quality and service reliability of composite material components.

[0084] Currently, parameter optimization based on process experience and experimental feedback is commonly used to control the thermal buildup of thick-walled thermosetting composite components during curing. For example, in pultrusion, a suitable process window is found by repeatedly adjusting the mold zone temperature, zone length, or traction speed; in autoclave or curing oven processes, the possibility of thermal runaway is reduced by adjusting the heating rate, holding time, and curing program. However, these methods mainly rely on external process parameters and product molding results for correction, making it difficult to accurately predict the actual temperature evolution, exothermic behavior, and curing state inside thick-walled components during the process design stage. Therefore, when dealing with large-size, thick-section, or high-exothermic resin systems, problems such as excessively high internal peak temperatures, large temperature gradients, and uneven curing may still exist.

[0085] To address the aforementioned issues, this application provides a method for designing the thermal history of composite material molding. This method involves obtaining characteristic parameters of the composite material component; constructing a heat transfer-curing coupling model during the molding process to predict the internal temperature evolution and curing degree of the material; the heat transfer-curing coupling model indicating the relationship between curing heat release and material heat transfer; identifying a heat accumulation zone based on the heat transfer-curing coupling model; this zone indicating areas where heat release is concentrated during the curing process of the composite material component, heat is difficult to transfer outwards, and temperature spikes and peaks are likely to occur; designing external heat input paths and process parameters based on the heat accumulation zone; these process parameters are controllable parameters that regulate at least one of the following: the temperature change process of the composite material component, the heating duration, the relative motion state of the heat source, and the heat transfer boundary conditions; and adjusting the input path and process parameters to transform the heat release process when the composite material component crosses the heat accumulation zone from concentrated release to dispersed release.

[0086] In the above method, a heat transfer and curing coupling model that can correlate curing heat release and material heat transfer is constructed by combining the characteristic parameters of composite material components. The heat accumulation area during the curing process is accurately located, and the external heat input path and matching process parameters are designed in a targeted manner. This breaks the traditional process optimization mode of trial and error based on experience. It can realize accurate prediction and active control of the curing heat release process of thick-walled composite materials, transforming centralized heat release into decentralized heat release, thereby reducing the internal peak temperature, reducing the temperature difference, and improving the curing uniformity. This enables the stable manufacturing of thick-walled thermosetting composite material components and improves the quality of the prepared thick-walled composite material components.

[0087] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0088] The embodiments of this application are applicable to the molding process of thermosetting composite materials in which there is a coupling effect between the exothermic effect of resin curing and the heat transfer of the structure, including continuous pultrusion, autoclave curing, curing oven curing, fiber winding molding, resin transfer molding, and vacuum assisted resin transfer molding (VARTM).

[0089] Figure 1 This is a flowchart illustrating a method for designing the thermal history of composite material molding, as provided in an embodiment of this application. Please refer to... Figure 1 As shown, the method may include the following steps:

[0090] S101. Obtain the characteristic parameters of the composite material component.

[0091] The execution subject of this application embodiment can be an electronic device or a composite material molding thermal history design device installed in an electronic device. The composite material molding thermal history design device can be implemented by software or by a combination of software and hardware.

[0092] In one possible implementation, a composite material component refers to a composite material component with a large cross-sectional thickness or size, which has a hysteresis in internal heat transfer during curing and is prone to internal heat accumulation and temperature overshoot. The composite material component refers to a thick-walled thermosetting composite material component, which may include at least one of continuous composite material sucker rods, pultruded profiles, spiral wound pipes, pressure vessels, solid composite rods, and thick-walled composite material plates.

[0093] In one possible implementation, the characteristic parameters are used to indicate the material's thermal behavior, curing reaction characteristics, thermal conductivity, and product size and structure.

[0094] In some implementations, the characteristic parameters may include: resin curing kinetic parameters, resin reaction exothermic parameters, effective thermal conductivity of the composite material, and product structural parameters. Here, resin refers to thermosetting resin, a polymeric material constituting composite components that undergoes an irreversible cross-linking and curing reaction under heating conditions, releasing a large amount of heat. The resin can be epoxy resin.

[0095] In one possible implementation, resin curing kinetic parameters refer to parameters that describe the quantitative relationship between the resin curing reaction rate and temperature and degree of curing. Resin curing kinetic parameters may include: activation energy, pre-exponential factor, reaction order, degree of curing, and the relationship between the resin curing reaction rate.

[0096] In one possible implementation, the resin reaction exothermic parameter refers to the parameter describing the exothermic behavior of the resin curing process. The resin reaction exothermic parameter may include: the amount of heat released when the resin is fully reacted, the position of the exothermic peak, and the change in the exothermic rate.

[0097] In one possible implementation, the effective thermal conductivity of a composite material refers to the overall thermal conductivity of the composite material along the radial or axial direction, used to indicate the ease of heat transfer inside a thick-walled structure. The effective thermal conductivity of a composite material may include axial thermal conductivity and radial thermal conductivity.

[0098] In one possible implementation, the product structural parameters refer to parameters that describe the geometric dimensions and structural characteristics of the composite material component. The product structural parameters may include the thickness of the composite material component and the diameter of the composite material component.

[0099] In one possible implementation, the characteristic parameters may also include other thermal properties of the composite component, such as specific heat capacity and density. These other thermal properties can be obtained by performing conventional thermal analysis on the composite component.

[0100] In this way, by acquiring multi-dimensional characteristic parameters of resin curing kinetics, reaction exotherm, composite material thermal conductivity, and component structure, the resin curing reaction law and the heat transfer characteristics of thick-walled composite material components can be completely and accurately characterized. This provides accurate and reliable basic data support for the subsequent construction of heat transfer and curing coupling models and thermal history design, thereby ensuring the scientific nature, accuracy, and feasibility of process design. It also reduces the possibility of process deviations caused by missing or inaccurate parameters from the source, thereby improving product quality.

[0101] In one possible implementation, the resin curing kinetic parameters can be obtained by: using differential scanning calorimetry (DSC) to test the heat flow curves of the resin at different heating rates, and then fitting and calculating them using an autocatalytic kinetic model.

[0102] In one possible implementation, the exothermic parameters of the resin reaction can be obtained by: using DSC to test the heat flow curve of the resin curing process, then integrating the heat flow curve to obtain the total heat release, and determining the position of the exothermic peak and the change in the exothermic rate. The heat flow curve refers to the curve recording the relationship between the heat difference between the resin sample and the reference sample and the temperature during differential scanning calorimetry testing. It can intuitively reflect the heat change law of the resin throughout the entire heating and curing process, clearly presenting the node characteristics of the exothermic start, peak value, and end.

[0103] In one possible implementation, the effective thermal conductivity of the composite material can be obtained by testing the thermal diffusivity of the composite component using a laser flare method, and then calculating the axial thermal conductivity and radial thermal conductivity by combining the specific heat capacity and density.

[0104] In one possible implementation, the structural parameters of the product can be obtained by directly measuring the thickness and diameter of the composite material component using measuring tools such as calipers and diameter gauges.

[0105] S102. Based on the characteristic parameters, a heat transfer and curing coupling model is constructed in the molding process of composite material components to predict the internal temperature evolution and curing degree process of the material. The heat transfer and curing coupling model is used to indicate the relationship between curing heat release and material heat transfer.

[0106] In one possible implementation, the heat transfer-curing coupling model refers to a mathematical model that simultaneously includes the heat conduction equation and the curing kinetics equation. It is used to quantify the mutual influence between the heat release during resin curing and the heat transfer inside the material, and to predict the dynamic evolution of the temperature field and the degree of curing field during the molding process.

[0107] In one possible implementation, a heat transfer and curing coupling model for the molding process of composite components can be constructed as follows: the heat conduction equation is determined based on temperature, effective thermal conductivity of the composite material, degree of curing, and exothermic term per unit volume; the curing kinetic equation is determined based on pre-exponential factor, activation energy, preset gas constant, absolute temperature, degree of curing, reaction order, and reaction order; and the heat conduction equation and the curing kinetic equation are combined to form a heat transfer and curing coupling model.

[0108] Among them, the heat release per unit volume refers to the heat released by the resin curing reaction in a unit volume of composite material per unit time, which is used to quantify the contribution of curing heat release to the internal temperature field of the material.

[0109] For example, the heat conduction equation can be expressed as:

[0110]

[0111] Where k represents the effective thermal conductivity of the composite material, and T represents the temperature. This represents the heat release per unit volume, where, Indicates resin density, This indicates the amount of heat released when a unit mass of resin fully cures. This indicates the rate of resin curing reaction.

[0112] The mathematical model for the curing kinetics equation can be an autocatalytic model, or other curing kinetics models, the Arrhenius model, or a combination of any curing kinetics model and the Arrhenius model. For example, the autocatalytic model can be expressed as:

[0113]

[0114] in, The resin curing reaction rate is represented by A, the pre-exponential factor, E, and R, which indicates the pre-exponential gas constant (used to indicate the thermodynamic relationship between temperature and reaction rate; the pre-exponential gas constant is, for example, 8.314 joules per mole per Kelvin). T represents absolute temperature (which is the thermodynamic temperature in Kelvin, equal to the sum of Celsius temperature and 273.15 degrees Celsius (°C), and is the standard temperature reference for curing kinetics calculations). The degree of curing of the resin (the proportion of resin that has undergone curing reaction to the total resin, with a value ranging from 0 to 1) is indicated by m, which represents the reaction order (used to indicate the intensity of the catalytic effect of the cured product on subsequent reactions). This represents the catalytic contribution of the cured resin to the curing reaction, and n represents the non-catalytic reaction order (used to indicate the reactivity of the uncured resin itself). This indicates the reactive contribution of the uncured resin.

[0115] In one possible implementation, the working principle of the heat transfer-curing coupling model is as follows: the heat conduction equation takes temperature, the effective thermal conductivity of the composite material, and the heat release term per unit volume as inputs to calculate the evolution of the internal temperature of the material over time and space; the curing kinetics equation takes the current temperature, degree of curing, and kinetic parameters as inputs to calculate the changes in curing reaction rate and degree of curing in real time; the two form a closed-loop coupling through the temperature and heat release term per unit volume: temperature changes drive changes in the reaction rate, and the heat release from the reaction acts as an internal heat source to correct the temperature field, thereby accurately simulating the dynamic interaction process of temperature affecting the curing reaction and curing heat release changing the temperature in turn, realizing quantitative prediction of the internal temperature evolution and degree of curing process during the molding of thick-walled composite materials.

[0116] In this way, by combining the heat conduction equation with the curing kinetics equation to form a heat transfer-curing coupling model, the mutual influence between curing heat release and material heat transfer can be quantified, providing a reliable basis for the design of the thermal history of thick-walled composite material molding.

[0117] S103. Based on the heat transfer and curing coupling model, the heat accumulation zone is determined. The heat accumulation zone is used to indicate the area where the heat release during the curing process of composite material components is concentrated, the heat is difficult to transfer outward, and the temperature rise and temperature peak are likely to occur.

[0118] In one possible implementation, the heat accumulation zone refers to the area formed during the curing process of the composite material component. In this area, the resin's heat release rate is much greater than the material's thermal conductivity rate, and the heat cannot diffuse outward in time, which easily leads to a sharp rise in temperature and local temperature peak exceeding the standard. This is the target area that this application embodiment focuses on controlling.

[0119] In some implementations, the thermal accumulation zone is determined based on the heat transfer-solidification coupling model, which may include:

[0120] Based on the heat transfer-curing coupling model, the temperature field, degree of curing field, and heat release information of composite material components during the curing process are predicted; based on the temperature field, degree of curing field, and heat release information, the heat accumulation zone of composite material components during the curing process is identified.

[0121] In one possible implementation, the temperature field refers to the set of temperature distributions at different locations and times of the composite material component. It can indicate the overall and local temperature levels of the composite material component, as well as the temperature change trend. For example, the core temperature and surface temperature of the composite material component are both part of the temperature field data.

[0122] In one possible implementation, the curing degree field refers to the distribution of the degree of completion of the resin crosslinking reaction throughout the entire range of the composite component. The curing degree value ranges from 0 to 1, and the closer the value is to 1, the more fully the resin is cured. The curing degree field can indicate the reaction progress at different locations.

[0123] In one possible implementation, the exothermic information includes data such as the instantaneous exothermic rate, cumulative heat release, and peak exothermic value at various points on the composite component, which can indicate the intensity of the resin curing reaction.

[0124] In one possible implementation, based on the heat transfer and curing coupling model, the temperature field during the curing process of composite material components can be predicted. This can include: before the composite material component is formally molded, inputting characteristic parameters (effective thermal conductivity of composite material, resin density, heat release per unit mass of resin during complete curing, specific heat capacity, density, boundary heat transfer conditions, external heat input conditions, etc.) into the heat conduction equation in the heat transfer and curing coupling model, calculating the temperature values ​​at various locations and times throughout the molding process of the composite material component, obtaining complete temperature distribution data in advance, and realizing the prediction of the temperature field.

[0125] In one possible implementation, based on the heat transfer and curing coupling model, the degree of curing field during the curing process of composite material components can be predicted. This can include: before the composite material component is formally molded, inputting characteristic parameters (activation energy, pre-exponential factor, and reaction order) into the curing kinetic equation in the heat transfer and curing coupling model, and then combining the predicted temperature field to calculate the degree of curing values ​​at various locations and times throughout the molding process of the composite material component, thereby obtaining complete degree of curing distribution data in advance and realizing the prediction of the degree of curing field.

[0126] In one possible implementation, based on the heat transfer and curing coupling model, the heat release information during the curing process of composite material components can be predicted. This can include: before the composite material component is formally formed, by using the curing degree field and resin curing reaction rate predicted by the heat transfer and curing coupling model, combined with the heat release term per unit volume, calculating the heat release and heat release rate at each location and time of the composite material component, thereby obtaining the full-process heat release data and completing the prediction of heat release information.

[0127] In one possible implementation, identifying heat accumulation zones during the curing process of composite material components based on temperature field, cure degree field, and exothermic information may include: determining regions or stages that satisfy one or more of the following characteristics based on the predicted temperature field, cure degree field, and exothermic information: the rate of temperature increase within a preset time is greater than or equal to a preset temperature rise rate threshold; the internal peak temperature is greater than or equal to a preset temperature threshold; the rate of cure degree increase within a preset time is greater than or equal to a preset cure degree increase rate threshold; the instantaneous exothermic rate is greater than or equal to a preset exothermic rate threshold; the local cumulative heat release is greater than or equal to a preset cumulative heat release threshold; and the internal and external temperature difference is greater than or equal to a preset temperature difference threshold. Regions or stages satisfying one or more of the above characteristics can be identified as heat accumulation zones.

[0128] The preset heating rate threshold refers to the critical value of temperature rise, used to determine whether the local temperature of the component is rising rapidly. The preset curing degree increase rate threshold refers to the critical value of curing degree increase, used to determine whether the resin curing reaction has entered the rapid reaction stage. In one specific embodiment, the preset heating rate threshold can be 8°C per minute and the preset curing degree increase rate threshold can be 0.08°C per minute. In other embodiments, the preset heating rate threshold can be adjusted according to the resin system, component size, thermal stability requirements and molding process.

[0129] Among them, if the rate at which the temperature rises within a preset time is greater than or equal to a preset heating rate threshold, it can indicate that the temperature is rising rapidly; if the rate at which the degree of curing increases within a preset time is greater than or equal to a preset degree of curing increase rate threshold, it can indicate that the degree of curing is increasing rapidly.

[0130] In this way, the temperature field, degree of curing field and exothermic information are predicted by the heat transfer and curing coupling model. Based on the predicted temperature field, degree of curing field and exothermic information, the heat accumulation zone is determined. This method abandons the traditional method of relying on subjective judgment based on human experience. The judgment rules are unified and the results are objective and accurate. It can identify the areas where heat is concentrated and the reaction is intense during the curing process in advance. This provides a quantitative basis for the subsequent targeted design of external heat input paths and optimization of process parameters. It avoids problems such as sudden temperature rise and local overheating from the source and improves the molding quality of thick-walled composite material components.

[0131] S104. Based on the heat accumulation zone, design the input path and process parameters of external heat. The process parameters are controllable parameters that regulate at least one of the following: the temperature change process of the composite component, the heating time, the relative motion state of the heat source, and the heat transfer boundary conditions.

[0132] In one possible implementation, process parameters refer to adjustable molding control parameters that can directly determine the actual thermal history of the composite component.

[0133] In one possible implementation, the temperature change process refers to the temperature level, heating and cooling rhythm, and temperature sequence change pattern throughout the curing process of the composite component; the heating duration refers to the duration of continuous heating and reaction of the composite component within the heating zone; the relative heat source motion state refers to the relative movement speed and positional interaction between the composite component and the heating mold or the heat source in the temperature zone; and the heat transfer boundary conditions refer to the boundary heat transfer basic conditions of the heat transfer temperature and heat transfer range between the surface of the composite component and the external heat source.

[0134] In one possible implementation, during the pultrusion process, the temperature zones are directly divided by a segmented mold. The mold serves not only to shape and support the composite material component but also to act as a heating carrier, forming temperature zones along the molding direction. A heat transfer and curing coupling model is constructed based on the characteristic parameters of the composite material component. After accurately locating the heat accumulation zone where curing heat release is concentrated and heat conduction is obstructed, the temperature parameters and zone lengths of each temperature zone are designed accordingly. At the same time, the movement speed of the composite material component is controlled by adjusting the traction speed, and the residence time in different temperature zones is changed to construct an appropriate external heat input path. This allows the curing heat release of the composite material component to change from concentrated release to dispersed release when passing through the heat accumulation zone, reducing the possibility of sudden local temperature rises.

[0135] In one possible implementation, during the autoclave or curing oven process, the composite material component and the mold remain stationary. An equivalent temperature zone is formed by combining electronic equipment with sequential temperature control. The heat accumulation zone is located by combining the heat transfer and curing coupling model. The heating, cooling, and heat preservation programs corresponding to each equivalent temperature zone are designed to determine the input path of external heat. By adjusting the heating state and the residence time at each stage, the heat release process is lengthened, the heat transfer is balanced, and the heat accumulation problem is solved.

[0136] In some implementations, the process parameters include one or more of the following: temperature of each temperature zone, heating rate, holding time, total mold length, length of each temperature zone, component dwell time, and traction speed.

[0137] In one possible implementation, the temperature of each temperature zone refers to the heating temperature set in each independent temperature control section of the segmented heating mold, which is used to regulate the heating temperature of the composite component at different molding stages. It can affect the speed of resin curing reaction and the heat release intensity. The temperature of each temperature zone can be used to regulate at least one of the temperature change process and heat transfer boundary conditions of the composite component.

[0138] In one possible implementation, the heating rate refers to the range of temperature change of the composite component within a unit of time. It is used to control the speed of the overall temperature rise and avoid sudden temperature rise that could cause the resin to react violently and release heat in a short time. The heating rate can be used to regulate the temperature change process of the composite component.

[0139] In one possible implementation, the heat preservation time refers to the duration during which the composite material component is continuously heated under a certain constant temperature condition. This is used to ensure that the resin undergoes a full cross-linking reaction, balance the reaction progress at various points in the component, and improve the overall curing uniformity. The heat preservation time can be used to control at least one of the heating time and temperature change process of the composite material component.

[0140] In one possible implementation, the total mold length refers to the overall axial length of the mold along the molding direction, and the length of each temperature zone refers to the axial length of each independent temperature control section within the mold along the molding direction. The total mold length can be used to control at least one of the heating time and heat transfer boundary conditions of the composite material component.

[0141] In one possible implementation, the length of each temperature zone refers to the axial dimension of a single independent temperature control section within the segmented mold along the molding direction of the component. Combined with the traction speed, the dwell time of the component in the corresponding temperature control zone can be determined to lengthen or shorten the time span of the resin reaction. The length of each temperature zone can be used to control at least one of the heating time and heat transfer boundary conditions of the composite material component.

[0142] In one possible implementation, the component dwell time refers to the time it takes for a certain location of the composite component to pass through a certain temperature zone of the mold. It is equal to the length of the temperature zone divided by the traction speed and can be used to indicate the degree of response of the composite component in that temperature zone. For example, the buffer zone is 0.5 meters long and the traction speed is 0.2 meters per minute. Therefore, the dwell time of the composite component in the buffer zone is 2.5 (0.5 / 0.2) minutes. The component dwell time can be used to control the heating time of the composite component.

[0143] In one possible implementation, the traction speed refers to the speed at which the composite component moves through the die during the pultrusion process, and can directly determine the residence time of the composite component in each temperature zone of the die. For example, a traction speed of 0.2 meters per minute indicates that the composite component moves 0.2 meters per minute through the die. The traction speed can be used to control at least one of the relative heat source motion state and heating duration of the composite component.

[0144] In one possible implementation, the dwell time of the component can be changed by adjusting the total length of the mold, the length of each temperature zone, and the traction speed.

[0145] In this way, by flexibly combining and adjusting the above-mentioned process parameters, it is possible to design suitable external heat input paths from multiple dimensions such as temperature level, temperature change rhythm, heating time, spatial layout, and movement speed. This allows for targeted regulation of the reaction state of composite material components when crossing the heat accumulation zone, dispersing the originally concentrated release of curing heat over a longer time and space range, suppressing the problems of internal heat accumulation and excessively high temperature peaks. It is compatible with various molding processes such as pultrusion, autoclaves, and curing ovens, and can improve the molding quality of thick-walled thermosetting composite material components.

[0146] In some implementations, the input path of external heat includes a temperature path and a time path. The temperature path is used to indicate the overall temperature change of the composite component as the process progresses during molding, while the time path is used to indicate the duration of the composite component in different heating zones and different process stages.

[0147] Temperature paths include heating, cooling, holding, or combinations thereof; time paths include dwell time, holding time, material transit time, or combinations thereof.

[0148] In one possible implementation, during the pultrusion process, heating, cooling, heat preservation, or a combination thereof can be used to divide the mold into multiple temperature zones. The time it takes for the composite material component to pass through each temperature zone can be set in conjunction with the traction speed, thereby lengthening the resin reaction cycle and allowing the heat released from the heat accumulation zone to be released gradually. This makes the heat release rate match the heat transfer rate, reducing the possibility of heat accumulation and overheating.

[0149] For example, taking the mold as a three-section temperature zone, the first temperature zone is heated to 140°C, the second temperature zone is a heat accumulation zone, which is kept at 140°C throughout, and the third temperature zone is slowly heated to 155°C and kept at that temperature to avoid sudden local temperature rises; the composite material component takes 90 seconds to pass through the first temperature zone; the composite material component takes 120 seconds to stay in the second heat accumulation zone and for 120 seconds to keep at that temperature; and the composite material component takes 80 seconds to pass through the third temperature zone.

[0150] In one possible implementation, in the autoclave or curing oven process, heating, cooling, heat preservation, or a combination thereof can be used to divide the process into multiple time-series equivalent temperature zones, and then the duration of each temperature zone can be set. There is no movement of the composite material components as a whole. The heat preservation time and the dwell time of each stage are used as core time parameters. Finally, curing can be carried out based on the designed temperature and time path. By reducing the heating rate of stages where heat accumulation is likely to occur and extending the heat preservation time, the concentrated heat release during curing is broken up, allowing the heat to be gradually conducted and diffused, reducing the possibility of local overheating.

[0151] For example, three equivalent temperature zones are designed. The first temperature zone is heated slowly to 135°C. The second temperature zone (the process stage corresponding to heat accumulation) is kept at a constant temperature of 135°C. The third temperature zone is slowly heated to 150°C and then gradually cooled after curing. The heating stage corresponding to the first temperature zone lasts for 60 minutes, the heat preservation stage corresponding to the second temperature zone lasts for 150 minutes, and the heating stage corresponding to the third temperature zone lasts for 40 minutes.

[0152] In this way, by designing temperature and time paths, the coupling law of heat transfer and curing can be matched, the overall reaction cycle of the resin can be lengthened, and the concentrated release of curing heat can be separated. This ensures that the heat release rate of the resin and the heat transfer rate of the composite material are always coordinated, weakening the heat accumulation effect and reducing the possibility of sudden temperature rise and high temperature peaks inside the composite material component. This can improve the overall curing uniformity and molding quality of the composite material component, and also avoid defects such as component cracking and performance degradation caused by local overheating.

[0153] S105. By adjusting the input path and process parameters, the heat release process of the composite material component when crossing the heat accumulation zone is changed from concentrated release to dispersed release.

[0154] In one possible implementation, by adjusting the input path and process parameters, the composite material component slowly enters the reaction state, and the curing heat that was originally released in a short period of time is dispersed and released over a longer time and space range. After the adjustment, the heat transfer and curing coupling model is run again to verify the actual control effect of the input path and process parameters. If the verification results meet the quality indicators such as temperature, temperature difference, and degree of curing, the current thermal history scheme is determined to be the final scheme.

[0155] In this embodiment, characteristic parameters of the composite material component are obtained; based on the characteristic parameters, a heat transfer and curing coupling model is constructed during the molding process of the composite material component to predict the internal temperature evolution and curing degree process of the material. The heat transfer and curing coupling model is used to indicate the relationship between curing heat release and material heat transfer; based on the heat transfer and curing coupling model, a heat accumulation zone is determined. The heat accumulation zone is used to indicate the area where the reaction heat release is concentrated during the curing process of the composite material component, the heat is difficult to transfer outward, and the temperature rise and temperature peak are likely to occur; based on the heat accumulation zone, the external heat input path and process parameters are designed. The process parameters are controllable parameters that regulate at least one of the following: the temperature change process of the composite material component, the heating time, the relative heat source motion state, and the heat transfer boundary conditions; by adjusting the input path and process parameters, the heat release process when the composite material component crosses the heat accumulation zone is changed from concentrated release to dispersed release.

[0156] In the above method, a heat transfer and curing coupling model that can correlate curing heat release and material heat transfer is constructed by combining the characteristic parameters of composite material components. This model can accurately locate the heat accumulation area during the curing process and design the input path of external heat and matching process parameters. It breaks the traditional experience-based trial and error process optimization mode, and can achieve accurate prediction and active control of the curing heat release process of thick-walled composite materials. It transforms centralized heat release into decentralized heat release, thereby reducing the internal peak temperature, reducing the temperature difference, and improving the curing uniformity. This enables the stable manufacturing of thick-walled thermosetting composite material components and improves the quality of the prepared thick-walled composite material components.

[0157] Based on the above embodiments, the input path can be implemented in at least one of the following ways:

[0158] Mold temperature zone control; autoclave heating program; curing oven heating program; heating platform temperature control; induction heating control; infrared heating control.

[0159] In one possible implementation, the working principle of mold temperature zone control is as follows: the mold is divided into multiple independent temperature-controlled sections along the molding direction of the composite component. The temperature and length of each temperature zone are set by the mold heating unit, and the heating time is changed in combination with the moving speed of the composite component, forming a spatial temperature and time path. This method is suitable for pultrusion processes, relying on segmented temperature zones for zoned heating to precisely control the thermal history of the composite component during its movement.

[0160] In one possible implementation, the autoclave heating program works by using a timed heating, cooling, and heat preservation program, integrated with the autoclave heating unit and the electronic control system, to divide the complete curing cycle into multiple time-equivalent temperature zones, continuously providing heat to the composite material component in a static state. This method is suitable for autoclave integral curing processes and can be used for curing and molding wound components and large, thick-walled composite material products.

[0161] In one possible implementation, the curing oven heating program operates similarly to the autoclave heating program. Based on the curing oven heating unit, a multi-segment temperature control program is used to divide the time-sequential equivalent temperature zones, completing heating, holding, and cooling operations according to a predetermined rhythm to provide stable heat input for the static composite material components inside the oven. This method is suitable for box-type curing ovens and tunnel-type curing ovens, and can process various components such as thick-walled plates and solid rods.

[0162] In one possible implementation, the working principle of the heating platform temperature control is as follows: The fixed heating platform is divided into zones for temperature control, allowing the composite material component to be placed on the platform surface and kept stationary. The heat input path is designed based on the temperature differences between different areas of the platform and the holding time. This method is suitable for the static curing process of flat and small irregularly shaped composite material components.

[0163] In one possible implementation, the working principle of induction heating control is as follows: based on the electromagnetic induction effect of the induction heating unit, eddy currents are generated inside or on the surface of the composite material to generate heat. By adjusting the induction power, the duration of action, and the heating zone to divide the temperature range, the overall thermal history can be flexibly controlled. This method can be adapted to various processes such as pultrusion and static curing, and is also suitable for continuous molding scenarios that require rapid and localized temperature control.

[0164] In one possible implementation, the infrared heating control works on the principle of infrared heating units, which transfer heat through infrared radiation. Multiple infrared heating modules are used to form independent temperature zones, each with its own set temperature and operating time, enabling zoned and time-based heating. This method is widely applicable to processes such as pultrusion and curing ovens, featuring uniform heating and flexible temperature control, and can be used for continuous or intermittent curing production of various thick-walled composite materials.

[0165] The descriptions of the mold heating unit, autoclave heating unit, curing oven heating unit, heating platform, induction heating unit, and infrared heating unit are provided in the subsequent embodiments and will not be repeated here.

[0166] It should be noted that the above-mentioned various heat input methods can all be combined with the identified heat accumulation area to optimize the temperature and time paths, transforming the concentrated curing heat release into a dispersed release, adapting to the molding needs of thick-walled composite materials in different production scenarios, reducing the possibility of heat accumulation and local overheating, and improving the product molding quality.

[0167] In this way, by implementing diversified heat input methods such as mold temperature zone control, various program temperature control, induction heating, and infrared heating, temperature and time paths can be flexibly built according to different molding processes, component types, and production scenarios. The heating mode, temperature parameters, and duration can be precisely adjusted for the heat accumulation area identified by the heat transfer and curing coupling model. This can disperse the heat release during curing, balance the heat release rate and heat transfer rate, and reduce the possibility of heat accumulation and local temperature surges from multiple dimensions. This can broaden the applicability of the embodiments of this application, meet different production needs, and continuously improve the curing uniformity of thick-walled composite material components, reduce molding defects such as cracking and uneven performance, and improve the overall product quality and process versatility.

[0168] Next, combined Figure 2 This section details the methods for adjusting input paths and process parameters. For example, Figure 2 A flowchart illustrating a method for adjusting input paths and process parameters provided in this application embodiment is shown below. Figure 2 As shown, the method includes:

[0169] S201. Set the target range for the curing and molding parameters of the composite material component, and after adjusting the input path and process parameters, calculate the actual value of the curing and molding parameters of the composite material component through the heat transfer and curing coupling model.

[0170] In one possible implementation, curing parameters are key indicators for measuring the curing quality and stability of thick-walled composite materials, and can be used to indicate internal heat accumulation, temperature uniformity, and curing synchronicity.

[0171] In some implementations, the curing parameters include one or more of the following: the highest internal temperature of the composite component, the radial temperature difference between the inside and outside, the difference in curing degree between the inside and outside at the outlet, the degree of curing at the outlet, and the final degree of curing.

[0172] In one possible implementation, the highest internal temperature of the composite component refers to the highest temperature that occurs in the internal region during the curing process. Excessive temperature can lead to resin degradation, material embrittlement, and even internal cracking. The radial internal-external temperature difference refers to the temperature difference between the outer and inner layers of the radial cross-section of the composite component. Excessive temperature difference can easily cause thermal stress, interface delamination, or internal splitting. The difference in curing degree between the inner and outer layers at the exit refers to the difference between the curing degree of the outer layer and the curing degree of the inner layer of the composite component. A large difference indicates asynchronous curing, which affects the overall mechanical properties. The degree of curing at the exit refers to the overall average degree of curing when the composite component leaves the mold exit position (for pultrusion process) or when the composite component finishes curing (for autoclave and / or curing oven process). The final degree of curing refers to the final average degree of curing achieved by the composite component after completing all molding, heat preservation, and cooling processes.

[0173] In this way, by defining the highest internal temperature, radial internal and external temperature difference, internal and external curing degree difference at the outlet, outlet curing degree, and final curing degree as curing and molding parameters, the molding quality of thick-walled composite material components can be comprehensively quantified from the dimensions of reaction heat extreme value, cross-sectional temperature uniformity, and overall curing synchronicity. This solves the problems of heat accumulation, temperature unevenness, and asynchronous curing during the curing process of thick-walled components, provides quantitative evaluation indicators and judgment basis for subsequent iterative adjustment of process parameters, realizes the traceability and control of curing and molding defects, and thus improves the quality of the prepared thick-walled composite material components.

[0174] In one possible implementation, the target range refers to the preset safety range of the curing parameters, which can indicate the target boundary for process optimization. For example, the target range corresponding to the highest internal temperature is less than or equal to 210°C, the target range corresponding to the radial internal-external temperature difference is less than or equal to 30°C, the target range corresponding to the difference in curing degree between the internal and external parts at the outlet is less than or equal to 0.05, the target range corresponding to the degree of curing at the outlet is greater than or equal to 0.8, and the target range corresponding to the final degree of curing is greater than or equal to 0.95.

[0175] In one possible implementation, the actual value is the simulation result of the curing and molding parameters under the current process parameters calculated by the heat transfer and curing coupling model, which is used to compare with the target range to determine whether the process is qualified.

[0176] In one possible implementation, after adjusting the input path and process parameters, the actual values ​​of the curing and molding parameters of the composite material component are calculated using a heat transfer and curing coupling model. This may include:

[0177] The adjusted process parameters (total mold length, length of each temperature zone, and traction speed) and pre-acquired characteristic parameters (resin curing kinetic parameters, resin reaction exothermic parameters, effective thermal conductivity of composite material, and product structural parameters) are input into the heat transfer and curing coupling model. The heat conduction equation and curing kinetic equation in the heat transfer and curing coupling model are solved numerically to simulate the temperature field evolution and curing degree field evolution of the composite material component during the molding process. The highest internal temperature of the composite material component, the temperature difference at different positions of the radial section, and the curing degree difference between the inner and outer layers of the outlet section are extracted from the simulation results, which are the actual values ​​of the curing and molding parameters.

[0178] S202. When the actual value meets the corresponding target range, it indicates that the input path and process parameters have been adjusted appropriately.

[0179] In one possible implementation, when any actual value in the curing parameters meets the corresponding target range, it can be indicated that the input path and process parameters have been properly adjusted.

[0180] It should be noted that if no obvious thermal runaway behavior is observed inside the composite material component, it can be considered that the input path and process parameters have been properly adjusted, and there is no need to readjust the input path and process parameters.

[0181] In one possible implementation, methods for determining whether thermal runaway behavior exists may include:

[0182] First, the temperature field results are output using a heat transfer-curing coupling model. Then, based on these results, it is determined whether the internal temperature of the composite component experiences a rapid increase in a short period, whether a sharp temperature peak is formed exceeding the upper limit of the resin system's allowable safe temperature, whether the curing reaction rate undergoes abrupt changes in a localized area, and whether the heat release per unit volume increases significantly. If any of these conditions occur, it indicates that internal heat is rapidly and cannot be conducted outwards, thus indicating internal thermal runaway. If none of these conditions occur, it indicates that the temperature changes gradually, there are no sharp peaks, heat release is uniform, and heat can be conducted normally, thus indicating that no thermal runaway has occurred. In one embodiment, the internal peak temperature, the maximum internal-external temperature difference, and the difference in curing degree between the internal and external parts at the outlet can be further combined to comprehensively determine the thermal runaway behavior.

[0183] The upper limit of the safe temperature refers to the highest permissible temperature at which the resin matrix will not undergo thermal degradation or irreversible performance deterioration. This temperature is determined by the resin's own thermal stability; below this temperature, the resin remains stable, while above this temperature, molecular chains break, the material becomes brittle, and internal defects are generated. For example, the upper limit of the safe temperature is 210℃.

[0184] S203. When the actual value does not meet the corresponding target range, readjust the input path and process parameters, and then recalculate the actual value through the heat transfer and curing coupling model and make a judgment until the set target range is met.

[0185] In one possible implementation, when none of the actual values ​​in the curing and molding parameters meet the corresponding target range, it can be indicated that the input path and process parameters need to be adjusted. After the adjustment, the updated actual values ​​in the curing and molding parameters need to be recalculated through the heat transfer and curing coupling model, and each actual value is compared with the corresponding target range. When any actual value meets the corresponding target range, the adjustment of the input path and process parameters can be terminated.

[0186] It should be noted that if obvious thermal runaway behavior occurs inside the composite component and none of the actual values ​​in the curing and molding parameters meet the corresponding target range, it means that the input path and process parameters need to be adjusted. After adjustment, the updated actual values ​​in the curing and molding parameters can be recalculated through the heat transfer and curing coupling model. When no obvious thermal runaway behavior occurs inside the composite component, or when any of the updated actual values ​​meets the corresponding target range, the adjustment of the input path and process parameters can be stopped.

[0187] In this embodiment, a target range is set for the curing and molding parameters of the composite material component. After adjusting the input path and process parameters, the actual value of the curing and molding parameters of the composite material component is calculated by the heat transfer and curing coupling model. When the actual value meets the corresponding target range, it indicates that the input path and process parameters have been adjusted appropriately. When the actual value does not meet the corresponding target range, the input path and process parameters are readjusted, and the actual value is recalculated by the heat transfer and curing coupling model and judged again until the target range is met.

[0188] In the above method, the target range of curing and molding parameters is set in advance as the judgment standard. The actual value after process adjustment is calculated iteratively by combining the heat transfer and curing coupling model. At the same time, it is determined whether thermal runaway occurs inside the composite material component. Based on the comparison results of the actual value and the corresponding target range, the external heat input path and various process parameters are continuously optimized until all indicators meet the standards. Quantitative data can replace traditional manual experience trial and error, forming a closed-loop parameter iterative optimization process. It can accurately control the temperature state and reaction progress during the curing process, effectively reducing the possibility of problems such as thermal runaway, local overheating, excessive temperature difference, and asynchronous curing. This makes the molding process of thick-walled composite material components stable and controllable, continuously improving the structural integrity and overall mechanical properties of the finished product. At the same time, it also reduces the process debugging cost and trial and error cycle.

[0189] For example, Figure 3 This is a schematic diagram of a temperature zone setting provided in an embodiment of this application, such as... Figure 3 As shown, each temperature zone along the molding direction includes: a preheating zone, a buffer zone, and a finishing zone. The buffer zone accounts for 60% of the mold length, while the preheating zone and the finishing zone each account for 20% of the mold length. The temperature of the buffer zone is 120℃, the temperature of the preheating zone is 110℃, and the temperature of the finishing zone is 180℃.

[0190] In this context, the preheating zone can be understood as the first temperature zone in the above embodiment, the buffer zone can be understood as the second temperature zone in the above embodiment, and the completion zone can be understood as the third temperature zone in the above embodiment.

[0191] By employing a stepped temperature design combined with differentiated temperature zone lengths, the pultrusion process controls the travel time of the composite component through the traction speed. This allows the component to slowly heat up in a low-temperature preheating zone, gradually activating the resin reaction and avoiding rapid, intense heat release. The buffer zone, corresponding to the heat accumulation zone mentioned in the previous embodiment, uses a lower constant temperature for extended periods, lengthening the resin's heat release cycle and gradually dispersing and conducting the concentrated heat release, reducing the possibility of sudden internal temperature rises and heat accumulation. Finally, the component enters the finishing zone where the temperature is increased, allowing the resin to fully cross-link and cure. The entire temperature zone layout and parameters work together to create a reasonable temperature and time path, ensuring that the resin's heat release rate and the composite material's heat transfer rate are always matched. This reduces the possibility of local overheating and cracking, while ensuring thorough and uniform curing of the component, thereby improving the molding quality of thick-walled composite components.

[0192] When applied to autoclave or curing oven processes, the equivalent temperature zones can be divided according to the three-stage partitioning logic described above. A preheating stage (corresponding to the preheating zone), a buffer insulation stage (corresponding to the buffer zone), and a curing completion stage (corresponding to the completion zone) are set sequentially, with each stage accounting for 20%, 60%, and 20% of the total time, respectively. The set temperatures for each stage are also 110℃, 120℃, and 180℃. The composite material component and mold remain stationary throughout the process. Combined with the temperature control program of the electronic equipment, a segmented heating, constant temperature, and reheating sequence is executed. In the preheating stage, the temperature is increased at a low speed to smoothly initiate the resin curing reaction. In the buffer insulation stage, a constant temperature is maintained for a long time to break down the concentrated release of curing heat and ensure a steady outward transfer of heat. In the curing completion stage, the temperature is increased to drive the resin to completely complete the cross-linking reaction. This sequential equivalent temperature zone design forms a temperature and time path that is adapted to static curing conditions. It can balance the heat release rate and heat transfer rate, reduce the possibility of heat accumulation inside the component, excessive temperature difference, and asynchronous curing. While improving the curing effect, it reduces the possibility of resin thermal degradation and component delamination and splitting, thereby improving the molding quality and performance of thick-walled composite material components.

[0193] In one example, the following provides a comparison between process A and the thermal history design method for thick-walled composite molding provided in the embodiments of this application (process B).

[0194] In process A, a monotonically increasing temperature zone and an equal-length mold structure are adopted. For example, if the total length of the mold is A mm, then the lengths of the front temperature zone, the middle temperature zone, and the rear temperature zone are all A / 3 mm. The temperature of the front temperature zone is temperature A, the temperature of the middle temperature zone is the sum of temperature A and 20℃, and the temperature of the rear temperature zone is the sum of temperature A and 40℃.

[0195] Process B uses a mold with a total length greater than that used in Process A. The total length of the mold in Process B is B millimeters (B is greater than A). The diameter of the component using Process B is greater than 15 millimeters, and the component uses a carbon fiber or glass fiber reinforced epoxy resin system with significant exothermic characteristics. In Process B, the length of the front temperature zone is the same as the length of the rear temperature zone, the middle temperature zone is the longest, the temperature of the front temperature zone is temperature B, the temperature of the middle temperature zone is similar to or slightly lower than the temperature of the front temperature zone, and the temperature of the rear temperature zone is higher than the temperature of the middle temperature zone, used to complete the curing. In Process B, the traction speed is speed A.

[0196] For example, Figure 4 This is a schematic diagram illustrating a reaction rate comparison provided in an embodiment of this application. Figure 4 It can be seen that the reaction rate inside the component using process B is 68% lower than the reaction rate inside the component using process A.

[0197] For example, Figure 5 This is a schematic diagram of peak temperature comparison provided in an embodiment of this application. Figure 5 It can be seen that the peak temperature inside the component using process B is 53°C lower than that inside the component using process A, and the peak temperature inside the component using process B is shifted backward compared to that inside the component using process A.

[0198] For example, Figure 6 This is a schematic diagram illustrating a radial and internal / external temperature difference comparison provided in an embodiment of this application. Figure 6 (a) It can be seen that the radial internal and external temperature difference of the component using process A is 68℃. Figure 6 (b) It can be seen that the radial temperature difference between the inside and outside of the component using process B is 28°C, which is lower than that of the component using process A. This indicates that the temperature distribution along the cross-section of the material can be more uniform using process B. In addition, in process A, the temperature at the center point of the component shows a significant sudden increase after entering the middle temperature zone; while in process B, this sudden increase is weakened or disappears. This shows that by extending the residence time of the material in the middle temperature zone, the resin reaction changes from a short-term concentrated event to a gradual process over a longer period of time, thereby reducing the exothermic intensity per unit time.

[0199] For example, Figure 7 This is a schematic diagram illustrating the difference in curing degree between the inside and outside of the outlet, provided in an embodiment of this application. Figure 7 (a) It can be seen that the difference in curing degree between the inside and outside of the outlet of the component using process A is 0.2. Figure 7 (b) It can be seen that the curing degree difference between the inside and outside of the component using process B is 0.02℃, which is lower than that of the component using process A. This indicates that the curing process inside and outside the component tends to be consistent, which can improve the problem of uneven curing.

[0200] In summary, by adjusting process parameters and the input path of external heat, the embodiments of this application can transform the reaction process from a concentrated occurrence to a phased process, thereby reducing the heat release intensity per unit time, minimizing the possibility of internal heat accumulation and temperature overshoot, reducing the internal and external temperature difference, synchronizing the curing process, avoiding resin degradation and structural defects, improving the curing uniformity of composite material components, and enhancing the stability of product quality.

[0201] Figure 8 This is a schematic diagram of a composite material molding thermal history design device provided in an embodiment of this application. Please refer to... Figure 8 The composite material molding thermal history design device 800 includes: an acquisition module 801, a construction module 802, a determination module 803, a design module 804, and an adjustment module 805, wherein...

[0202] The acquisition module 801 is used to acquire the characteristic parameters of the composite material component;

[0203] Module 802 is used to construct a heat transfer and curing coupling model in the molding process of composite material components based on characteristic parameters, so as to predict the internal temperature evolution and curing degree process of the material. The heat transfer and curing coupling model is used to indicate the relationship between curing heat release and material heat transfer.

[0204] The determination module 803 is used to determine the heat accumulation zone based on the heat transfer and curing coupling model. The heat accumulation zone is used to indicate the area where the reaction heat release is concentrated during the curing process of composite material components, the heat is difficult to transfer outward, and the temperature rise and temperature peak are likely to occur.

[0205] Design module 804 is used to design the input path and process parameters of external heat based on the heat accumulation zone. The process parameters are controllable parameters that regulate at least one of the following: temperature change process of composite material component, heating time, relative heat source motion state and heat transfer boundary conditions.

[0206] The adjustment module 805 is used to change the heat release process of composite material components crossing the heat accumulation zone from concentrated release to dispersed release by adjusting the input path and process parameters.

[0207] The composite material molding thermal history design device provided in this application embodiment can execute the technical solution shown in the above method embodiment. Its implementation principle and beneficial effects are similar, and will not be repeated here.

[0208] In one possible implementation, the determining module 803 is specifically used for:

[0209] Based on the heat transfer and curing coupling model, the temperature field, degree of curing field and heat release information of composite material components are predicted during the curing process.

[0210] Based on temperature field, curing degree field and exothermic information, the heat accumulation zone during the curing process of composite material components is identified.

[0211] In one possible implementation, the characteristic parameters include one or more of the following: resin curing kinetic parameters, resin reaction exothermic parameters, effective thermal conductivity of the composite material, and product structural parameters.

[0212] In one possible implementation, the external heat input path includes a temperature path and a time path. The temperature path is used to indicate the overall temperature change of the composite component as the process progresses during molding, and the time path is used to indicate the duration change of the composite component in different heating zones and different process stages.

[0213] Temperature paths include heating, cooling, holding, or combinations thereof;

[0214] The time path includes dwell time, heat preservation time, material transit time, or a combination thereof.

[0215] In one possible implementation, the input path is achieved in at least one of the following ways:

[0216] Mold temperature zone control;

[0217] Autoclave heating program;

[0218] Curing oven heating program;

[0219] Heating platform temperature control;

[0220] Induction heating control;

[0221] Infrared heating control.

[0222] In one possible implementation, the process parameters include one or more of the following: temperature of each temperature zone, heating rate, holding time, total mold length, length of each temperature zone, component dwell time, and traction speed.

[0223] In one possible implementation, the adjustment module 805 is specifically used for:

[0224] Target ranges are set for the curing and molding parameters of composite material components. After adjusting the input path and process parameters, the actual values ​​of the curing and molding parameters of composite material components are calculated by the heat transfer and curing coupling model.

[0225] When the actual value meets the corresponding target range, it indicates that the input path and process parameters have been adjusted appropriately.

[0226] When the actual value does not meet the corresponding target range, the input path and process parameters are readjusted, and the actual value is recalculated and judged through the heat transfer and curing coupling model until the set target range is met.

[0227] In one possible implementation, the curing parameters include one or more of the following: the highest internal temperature of the composite component, the radial temperature difference between the inside and outside, the difference in curing degree between the inside and outside at the outlet, the degree of curing at the outlet, and the final degree of curing.

[0228] The composite material molding thermal history design device provided in this application embodiment can execute the technical solution shown in the above method embodiment. Its implementation principle and beneficial effects are similar, and will not be repeated here.

[0229] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 9 As shown, the electronic device 900 may include: a transceiver 901, a processor 902, and a memory 903.

[0230] Processor 902 executes computer execution instructions stored in memory, causing processor 902 to perform the scheme in the above embodiments. Processor 902 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0231] The memory 903 is connected to the processor 902 via the system bus and completes communication between them. The memory 903 is used to store computer program instructions.

[0232] Transceiver 901 can be used to obtain the task to be run and its configuration information.

[0233] The system bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The system bus can be divided into address bus, data bus, control bus, etc. For ease of representation, only one thick line is used in the diagram, but this does not indicate that there is only one bus or one type of bus. Transceivers are used to enable communication between database access devices and other computers (e.g., clients, read-write libraries, and read-only libraries). Memory may include random access memory (RAM) and may also include non-volatile memory.

[0234] This application also provides a chip for executing instructions, which is used to execute the technical solution of the composite material molding thermal history design method in the above embodiments.

[0235] This application also provides a computer-readable storage medium storing computer instructions. When the computer instructions are executed on a computer, the computer performs the technical solution of the composite material molding thermal history design method described in the above embodiments.

[0236] This application also provides a composite material component, which is manufactured by the composite material molding thermal history design method described in the above embodiments.

[0237] This application embodiment also provides a composite material component molding system, which includes an external heat input unit and a control unit. The control unit is configured to execute the composite material molding thermal history design method in the above embodiment to control the external heat input unit to apply external heat input to the composite material component. The external heat input unit includes one or more of the following: a mold heating unit, an autoclave heating unit, a curing oven heating unit, a heating platform, an induction heating unit, and an infrared heating unit.

[0238] This application also provides a continuous molding apparatus, which includes a mold having a temperature zone structure for changing the heat release process of a composite material component across a heat accumulation zone from concentrated release to dispersed release.

[0239] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or modules, and may be electrical, mechanical, or other forms.

[0240] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to implement the solution of this embodiment according to actual needs.

[0241] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The unit composed of the above modules can be implemented in hardware or in the form of hardware plus software functional units.

[0242] The integrated modules described above, implemented as software functional modules, can be stored in a computer-readable storage medium. These software functional modules, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods of the various embodiments of this application.

[0243] It should be understood that the aforementioned processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. A general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly manifested as execution by a hardware processor, or execution by a combination of hardware and software modules within the processor.

[0244] The memory may include high-speed RAM, and may also include non-volatile memory (NVM), such as at least one disk storage device, and may also be a USB flash drive, external hard drive, read-only memory, disk or optical disc, etc.

[0245] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0246] The aforementioned storage media can be implemented from any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The storage media can be any available medium accessible to general-purpose or special-purpose computers.

[0247] An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Alternatively, the storage medium can be an integral part of the processor. The processor and storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and storage medium can exist as discrete components in an electronic control unit or main control device.

[0248] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0249] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for designing the thermal history of composite material molding, characterized in that, include: Obtain the characteristic parameters of composite material components; Based on the aforementioned characteristic parameters, a heat transfer and curing coupling model is constructed during the molding process of composite material components to predict the internal temperature evolution and curing degree process of the material. The heat transfer and curing coupling model is used to indicate the relationship between curing heat release and material heat transfer. Based on the heat transfer and curing coupling model, a heat accumulation zone is determined. The heat accumulation zone is used to indicate the area where the reaction heat release is concentrated during the curing process of the composite material component, the heat is difficult to transfer outward, and the temperature rise and temperature peak are likely to occur. Based on the heat accumulation zone, the input path and process parameters of external heat are designed. The process parameters are controllable parameters that regulate at least one of the following: the temperature change process of the composite material component, the heating time, the relative motion state of the heat source, and the heat transfer boundary conditions. By adjusting the input path and the process parameters, the heat release process of the composite material component when crossing the heat accumulation zone is changed from concentrated release to dispersed release.

2. The composite material molding thermal history design method according to claim 1, characterized in that, The determination of the heat accumulation zone based on the heat transfer-solidification coupling model includes: Based on the heat transfer and curing coupling model, the temperature field, degree of curing field, and heat release information of the composite material component during the curing process are predicted. Based on the temperature field, the degree of curing field, and the exothermic information, the heat accumulation zone during the curing process of the composite material component is identified.

3. The composite material molding thermal history design method according to claim 1, characterized in that, The characteristic parameters include one or more of the following: resin curing kinetic parameters, resin reaction exothermic parameters, effective thermal conductivity of composite material, and product structural parameters.

4. The composite material molding thermal history design method according to claim 1, characterized in that, The external heat input path includes a temperature path and a time path. The temperature path is used to indicate the overall temperature change of the composite material component as the process progresses during molding. The time path is used to indicate the duration change of the composite material component in different heating zones and different process stages. The temperature path includes heating, cooling, heat preservation, or a combination thereof; The time path includes dwell time, heat preservation time, material transit time, or a combination thereof.

5. The composite material molding thermal history design method according to claim 1, characterized in that, The input path is implemented in at least one of the following ways: Mold temperature zone control; Autoclave heating program; Curing oven heating program; Heating platform temperature control; Induction heating control; Infrared heating control.

6. The composite material molding thermal history design method according to claim 1, characterized in that, The process parameters include one or more of the following: temperature of each temperature zone, heating rate, holding time, total mold length, length of each temperature zone, component dwell time, and traction speed.

7. The composite material molding thermal history design method according to claim 1, characterized in that, The step of adjusting the input path and the process parameters to change the heat release process of the composite material component crossing the heat accumulation zone from concentrated release to dispersed release includes: A target range is set for the curing and molding parameters of the composite material component, and after adjusting the input path and the process parameters, the actual values ​​of the curing and molding parameters of the composite material component are calculated by the heat transfer and curing coupling model. When the actual value meets the corresponding target range, it indicates that the input path and the process parameters have been adjusted appropriately. When the actual value does not meet the corresponding target range, the input path and the process parameters are readjusted, and the actual value is recalculated and judged through the heat transfer and curing coupling model until the set target range is met.

8. The composite material molding thermal history design method according to claim 7, characterized in that, The curing and molding parameters include one or more of the following: the highest internal temperature of the composite material component, the radial internal and external temperature difference, the difference in curing degree between the internal and external parts at the outlet, the degree of curing at the outlet, and the final degree of curing.

9. A composite material component, characterized in that, The composite material component is prepared by the composite material molding thermal process design method according to any one of claims 1-8.

10. A composite material component molding system, characterized in that, The device includes an external heat input unit and a control unit, wherein the control unit is configured to execute the composite material molding thermal history design method according to any one of claims 1-8 to control the external heat input unit to apply external heat input to the composite material component; the external heat input unit includes one or more of a mold heating unit, an autoclave heating unit, a curing oven heating unit, a heating platform, an induction heating unit, and an infrared heating unit.

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