A method and device for simulation analysis of the performance of an elastomer seal of a piston rod

Abstract

The application provides a piston rod rubber plastic sealing performance simulation analysis method and device, and belongs to the technical field of rubber plastic sealing performance analysis. The method provided by the application: under the maximum working pressure, the simulation analysis of the first direction movement is carried out; the maximum deformation parameter is determined according to the analysis result; the piston rod simulation model is updated according to the maximum deformation parameter; the working pressure is unloaded to a plurality of first level working pressures, and the simulation analysis of the second direction movement under each first level working pressure is carried out, and the second direction is opposite to the first direction; the deformation change of the rubber plastic sealing is determined according to the stress and strain results of the multiple simulation analysis of the second direction; and the performance change of the rubber plastic sealing in the piston reciprocating movement process is determined according to the input pressure of the piston rod simulation model and the deformation change of the rubber plastic sealing. The piston rod rubber plastic sealing performance simulation analysis method and device provided by the application are used to accurately evaluate the performance of the rubber plastic reciprocating sealing in the typical aviation hydraulic product.

Description

Technical Field

[0001] This application relates to the field of performance analysis technology for rubber and plastic seals, and in particular to a method and apparatus for performance simulation analysis of rubber and plastic seals for piston rods. Background Technology

[0002] Aviation hydraulic systems are widely used in critical components of various aircraft, such as actuators, servo motors, and hydraulic tanks. These systems rely on hydraulic pressure to drive the reciprocating motion of piston rods. Rubber and plastic seals play a crucial role in these hydraulic systems. The performance of these seals directly affects the efficiency, durability, and safety of the hydraulic system. Therefore, accurately evaluating the performance of rubber and plastic seals under different operating conditions is essential for system design, optimization, and fault prediction.

[0003] Current technologies for macroscopic finite element simulation analysis of rubber and plastic seals typically employ finite element analysis (FEM) to simulate the seal's behavior under hydraulic pressure. Existing simulation methods usually assume a single pressure condition throughout the simulation process, meaning the pressure remains constant during both the extension and retraction strokes. The simulation model primarily infers the seal's performance by evaluating the stress, strain, and contact pressure under this single pressure condition. While this method may be effective for analysis under a single pressure condition, in real hydraulic systems, pressure often varies periodically, and the alternating high and low pressure background significantly impacts the seal's performance.

[0004] First, existing technologies neglect the background operating condition of alternating high and low pressure. That is, the high-pressure and low-pressure phases in the reciprocating stroke are not properly distinguished during simulation. This results in calculations that only reflect the sealing performance under a single pressure state, failing to realistically simulate the impact of alternating high and low pressure on the performance of rubber and plastic seals in actual hydraulic system operation. Second, existing methods typically calculate the piston rod's outgoing or incoming stroke during the low-pressure phase, ignoring the effect of plastic deformation on the plastic material after high-pressure loading. This plastic deformation effect in the low-pressure phase is not fully considered, causing the simulation to fail to accurately reflect the material hardening and deformation caused by high-pressure plastic deformation, thus making it impossible to accurately assess the seal's performance. Therefore, these two deficiencies lead to distorted simulation results, making it impossible to effectively evaluate the long-term performance and durability of rubber and plastic seals under actual high and low pressure cyclic conditions. Summary of the Invention

[0005] In view of this, this application provides a method and apparatus for simulating and analyzing the performance of rubber and plastic seals for piston rods, in order to accurately evaluate the performance of rubber and plastic reciprocating seals in typical aerospace hydraulic products.

[0006] Specifically, this application is implemented through the following technical solution:

[0007] The first aspect of this application provides a method for performance simulation analysis of rubber and plastic seals for piston rods, the method comprising:

[0008] Obtain the initial parameters of the rubber and plastic seal, and assemble a piston rod simulation model including the rubber and plastic seal according to the initial parameters;

[0009] Obtain the maximum working pressure of the piston rod, and perform finite element simulation analysis of the piston rod simulation model in the first direction under the maximum working pressure;

[0010] The maximum deformation parameters of the piston rod simulation model were determined based on the analysis results.

[0011] The initial parameters of the rubber-plastic seal are updated based on the maximum deformation parameter, thereby updating the piston rod simulation model;

[0012] For the updated piston rod simulation model, the working pressure is gradually unloaded to multiple first-level working pressures, and finite element simulation analysis is performed on the second-direction motion under each first-level working pressure, where the second direction is opposite to the first direction.

[0013] The deformation of the rubber-plastic seal is determined based on the stress-strain results of multiple finite element simulation analyses in the second direction.

[0014] The performance changes of the rubber-plastic seal during the piston reciprocating motion are determined based on the input pressure of the piston rod simulation model and the deformation changes of the rubber-plastic seal.

[0015] A second aspect of this application provides a simulation analysis device for the performance of rubber and plastic seals on piston rods. The device includes a construction module, a simulation module, and a processing module; wherein...

[0016] The construction module is used to obtain the initial parameters of the rubber and plastic seal and assemble a piston rod simulation model including the rubber and plastic seal according to the initial parameters.

[0017] The simulation module is used to obtain the maximum working pressure of the piston rod, and under the maximum working pressure, to perform finite element simulation analysis of the piston rod simulation model in the first direction of motion.

[0018] The simulation module is also used to determine the maximum deformation parameters of the piston rod simulation model based on the analysis results;

[0019] The simulation module is also used to update the initial parameters of the rubber-plastic seal according to the maximum deformation parameter, thereby updating the piston rod simulation model;

[0020] The simulation module is also used to gradually unload the working pressure to multiple first-level working pressures on the updated piston rod simulation model, and perform finite element simulation analysis on the second-direction motion under each first-level working pressure, wherein the second direction is opposite to the first direction.

[0021] The processing module is used to determine the deformation of the rubber-plastic seal based on the stress-strain results of multiple finite element simulation analyses in the second direction.

[0022] The processing module is also used to determine the performance changes of the rubber-plastic seal during the piston reciprocating motion based on the input pressure of the piston rod simulation model and the deformation changes of the rubber-plastic seal.

[0023] The method and apparatus for simulating and analyzing the performance of rubber and plastic seals for piston rods provided in this application consider the impact of plastic deformation of the rubber and plastic seals after being loaded to the maximum working pressure on the low-pressure stroke of the next cycle when performing macroscopic finite element simulation analysis of the piston rod. This allows for accurate evaluation of the performance changes of the rubber and plastic seals during the reciprocating motion of the piston. First, a finite element simulation analysis of the piston rod simulation model in the first direction of motion is performed under the maximum working pressure to determine the maximum deformation parameter. The piston rod simulation model is then updated based on the maximum deformation parameter. Next, the working pressure is gradually unloaded to multiple first-level working pressures. Under each first-level working pressure, a simulation analysis of the second-direction motion, which is opposite to the first direction, is performed. Finally, the performance changes are determined by combining the input pressure and deformation changes. Taking into account the actual working conditions of alternating high and low pressure, it distinguishes between the first direction of motion under high pressure and the second direction of motion under low pressure. It fully incorporates the influence of the plastic deformation of rubber and plastic materials after high pressure loading on the subsequent low pressure stroke, and solves the problem of distortion of results caused by single pressure working condition simulation and neglect of the influence of high pressure plastic deformation in the existing technology. It can more realistically simulate the actual operating state of the hydraulic system, thereby accurately evaluating the performance changes of rubber and plastic seals during the piston reciprocating motion. Attached Figure Description

[0024] Figure 1 A flowchart of Embodiment 1 of the simulation analysis method for the performance of rubber and plastic seals of piston rods provided in this application;

[0025] Figure 2 A schematic diagram illustrating the stress-strain state of a rubber-plastic seal, as shown in an exemplary embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the second embodiment of the performance simulation analysis device for the piston rod rubber and plastic seal provided in this application. Detailed Implementation

[0027] 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 represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.

[0028] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used herein are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0029] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0030] The following specific embodiments are given to illustrate the technical solution of this application in detail.

[0031] Figure 1 The flowchart is from Example 1 of the simulation analysis method for the performance of the rubber-plastic seal of the piston rod provided in this application. Please refer to... Figure 1 The method provided in this embodiment may include:

[0032] S101. Obtain the initial parameters of the rubber and plastic seal, and assemble a piston rod simulation model including the rubber and plastic seal according to the initial parameters.

[0033] Specifically, rubber-plastic seals are sealing elements made of rubber or plastic used to prevent fluid leakage. The initial parameters of rubber-plastic seals include material properties (such as elastic modulus and Poisson's ratio), geometric dimensions (such as inner diameter, outer diameter, and thickness), preload, and initial stress-strain curves. These initial parameters can be obtained through material testing of the rubber-plastic seals or based on data provided by the supplier. It should be noted that the stress-strain curves are obtained beforehand through experiments and are used to characterize the plastic properties of the plastic in the rubber-plastic seals when subsequently building a piston rod simulation model.

[0034] Furthermore, the implementation steps for assembling the piston rod simulation model including the rubber-plastic seal according to the initial parameters include:

[0035] (1) Extract the geometric and material parameters of the rubber-plastic seal based on the initial parameters;

[0036] Specifically, geometric parameters and material parameters are separated from the initial parameters of the rubber and plastic seal. Geometric parameters include the shape, size, and other appearance characteristics of the rubber and plastic seal, such as inner diameter, outer diameter, thickness, and cross-sectional profile; material parameters include the material properties of the rubber and plastic seal, such as elastic modulus, Poisson's ratio, density, hardness, and the unique performance parameters of rubber and plastic materials, such as temperature resistance and oil resistance.

[0037] (2) Create a three-dimensional model of the piston rod based on the geometric parameters;

[0038] Specifically, based on the determined geometric parameters of the rubber and plastic seals, a piston rod simulation model including the rubber and plastic seals is constructed using 3D modeling software. The piston rod simulation model not only includes the geometric shape of the rubber and plastic seals, but also accurately presents the structure of related components such as the piston rod and cylinder, ensuring that the dimensions and relative positions of each component meet the actual assembly requirements, and providing a precise geometric basis for subsequent simulations.

[0039] (3) Define the material properties of the three-dimensional model based on the material parameters and complete the assembly.

[0040] Specifically, based on the constructed piston rod simulation model, the material properties of the rubber and plastic seals in the piston rod simulation model are defined according to the determined material parameters, so that the piston rod simulation model can realistically reflect the physical response of the rubber and plastic seals under stress and other conditions. After the material properties are defined, the piston rod, rubber and plastic seals, cylinder and other components are virtually assembled according to the actual assembly relationship to form a complete piston rod simulation model.

[0041] Optionally, the piston rod simulation model includes: a rubber-plastic seal, a piston rod, and a cylinder body, wherein the rubber-plastic seal is in close contact with the piston rod and the cylinder body, and the piston rod is connected to the cylinder body.

[0042] S102. Obtain the maximum working pressure of the piston rod, and under the maximum working pressure, perform finite element simulation analysis on the piston rod simulation model to analyze the motion in the first direction.

[0043] Specifically, the maximum working pressure is determined based on the actual working conditions of the piston rod. In the finite element analysis software, the maximum working pressure is applied to the piston rod simulation model, driving it to move in the first direction. It should be noted that the first direction can be either the extension direction or the retraction direction of the piston rod. Using the finite element method, the stress, strain, and contact pressure of the rubber-plastic seal are calculated during this process, focusing on capturing the deformation state, stress distribution, and contact with other components of the seal under high pressure.

[0044] S103. Determine the maximum deformation parameters of the piston rod simulation model based on the analysis results.

[0045] Specifically, based on the analysis results of the piston rod simulation model under maximum working pressure, the maximum deformation parameters (such as stress and strain) of the piston rod simulation model are extracted. These parameters reflect the ultimate deformation state of the seal under high pressure.

[0046] Furthermore, the steps for determining the maximum deformation parameter of the piston rod simulation model based on the analysis results include:

[0047] (1) Define multiple key deformation parameters;

[0048] Specifically, several key parameters that can reflect the deformation characteristics of the piston rod simulation model are identified. Combining the characteristics of rubber and plastic seals and simulation requirements, the key deformation parameters include the strain, contact pressure, and contact area of ​​the rubber and plastic seals. These key deformation parameters are directly related to the sealing performance and structural stability of the seals.

[0049] (2) Determine the parameter changes of each key deformation parameter between each key deformation parameter and the initial parameter based on the analysis results;

[0050] Specifically, based on the finite element simulation analysis results of the motion in the first direction under maximum working pressure, the differences between each key deformation parameter and the initial parameters (i.e., the parameter baseline values ​​set before simulation) are calculated, i.e., parameter changes. For example, if the strain of the rubber-plastic seal in the initial parameters is 1, while the simulation analysis results show that the actual strain of this part under maximum working pressure is 3, then the parameter change of this key deformation parameter is 2.

[0051] (3) Update the values ​​of each key deformation parameter in the initial parameters according to the parameter changes to obtain the maximum deformation parameter.

[0052] Specifically, the changes in each key deformation parameter obtained above are used as incremental values ​​to sum and update the initial parameters. The updated values ​​can truly reflect the ultimate deformation state of the piston rod simulation model under the maximum working pressure, which is the maximum deformation parameter.

[0053] S104. Update the initial parameters of the rubber-plastic seal according to the maximum deformation parameter, thereby updating the piston rod simulation model.

[0054] Specifically, the maximum deformation parameters include maximum strain, maximum contact pressure, and maximum contact area. The steps to update the initial parameters of the rubber-plastic seal based on the maximum deformation parameters include:

[0055] (1) Calculate the maximum plastic strain of the rubber-plastic seal based on the maximum deformation parameter;

[0056] Specifically, based on the maximum deformation parameter, the maximum plastic strain generated by the rubber-plastic seal under the maximum working pressure and the first direction of motion is calculated using the stress-strain data from the finite element simulation analysis results. Plastic strain is a permanent deformation of the material that cannot be recovered after being subjected to force, and it has a significant impact on the subsequent performance of the rubber-plastic seal (such as sealing performance and durability), and is the core basis for updating the parameters.

[0057] (2) Update the material and geometric parameters of the rubber-plastic seal according to the maximum plastic strain;

[0058] Specifically, the initial parameters of the rubber and plastic seals are adjusted based on the calculated maximum plastic strain. The updating of material parameters mainly addresses changes in material properties caused by plastic deformation, such as hardening (changes in elastic modulus) and decreased toughness in rubber and plastic materials. The updating of geometric parameters addresses permanent deformations of the seals caused by plastic strain, such as changes in cross-sectional dimensions and contact area contours, ensuring that the parameters reflect the true state under high pressure.

[0059] (3) Assemble a piston rod simulation model including the updated rubber and plastic seals according to the material parameters and geometric parameters.

[0060] Specifically, based on the updated material and geometric parameters, the model of the rubber-plastic seal was reconstructed and virtually assembled with other components such as the piston rod and cylinder according to actual assembly relationships, forming an updated piston rod simulation model. This model incorporates the influence of plastic deformation under high pressure, providing a more realistic basis for subsequent simulation of second-direction motion under low-pressure conditions, and ensuring the consistency and accuracy of simulation under alternating high and low pressure conditions.

[0061] The maximum plastic strain of the rubber-plastic seal is calculated by the maximum deformation parameter. Based on this, the material parameters (such as material hardening and changes in elastic modulus due to plastic deformation) and geometric parameters (such as changes in cross-sectional dimensions and contact contours due to permanent deformation) of the rubber-plastic seal are updated. The piston rod simulation model is then reassembled, incorporating the irreversible influence of plastic deformation of the rubber-plastic material on the seal under the maximum working pressure condition. This allows the updated piston rod simulation model to realistically reflect the state after the maximum working pressure is applied, providing a realistic basis for subsequent simulation analysis under alternating high and low pressure conditions. This ensures the continuity and accuracy of the simulation from high pressure to low pressure, thereby improving the realism and reliability of the performance evaluation of the rubber-plastic seal during the entire piston assembly process. It is especially suitable for accurately simulating the performance of rubber-plastic reciprocating seals in aviation hydraulic systems under complex working conditions.

[0062] S105. For the updated piston rod simulation model, the working pressure is gradually unloaded to multiple first-level working pressures, and finite element simulation analysis is performed on the second-direction motion under each first-level working pressure, wherein the second direction is opposite to the first direction.

[0063] Specifically, starting from the maximum working pressure, a gradual unloading method is used to reduce the working pressure from the maximum working pressure to multiple preset first-level working pressures. These multiple first-level working pressures have different pressure values, thus covering various low-pressure conditions that may occur in actual hydraulic systems and more comprehensively simulating the impact of pressure fluctuations on rubber and plastic seals. It should be noted that the first-level working pressure can be a low-pressure value under different working conditions or a different pressure value under the same working condition; this embodiment does not limit it.

[0064] Under each first-level working pressure, a finite element simulation analysis is performed on the piston rod simulation model to show movement in a second direction opposite to the first direction (e.g., if the first direction is piston rod extension, then the second direction is retraction). This analysis allows for the acquisition of stress-strain data of the seal under different low-pressure conditions and during reverse movement, including key information such as changes in contact pressure and the degree of deformation.

[0065] Furthermore, the unloading range of working pressure is defined by taking the maximum working pressure as the starting point of pressure unloading and the minimum first level working pressure as the ending point of pressure unloading. The unloading range is divided into stages according to the multiple working conditions of the piston rod, and the first level working pressure corresponding to each stage is calculated according to the preset step size coefficient.

[0066] Specifically, the maximum working pressure of the piston rod is taken as the unloading starting point, and the lowest first-level working pressure (such as near zero pressure or the lowest operating pressure of the system) is taken as the unloading endpoint. The total range of pressure change is defined, and the unloading process from the maximum working pressure to the lowest first-level working pressure is divided into multiple stages. Each stage corresponds to a different pressure reduction rate. The pressure unloading step size is set for each stage according to a preset step size coefficient. The step size refers to the amount of pressure unloaded in each stage, so that the pressure can decrease at different rates in different stages. According to the set stages and the corresponding step size coefficient, the endpoint pressure value of each stage is calculated as multiple first-level working pressures to ensure that the pressure value covers the key nodes in the unloading process. It should be noted that the step size coefficient of each stage is set according to actual needs and can be the same or different. In this embodiment, it is not limited. By simulating the non-uniform characteristics of pressure change in an actual hydraulic system: in the high-pressure range, the pressure may drop rapidly due to the fast response of the system unloading valve; in the low-pressure range, the unloading rate may slow down to avoid excessive pressure fluctuations. By adjusting the rate in stages, the deformation response of rubber and plastic seals under different pressure gradients can be captured more realistically, especially highlighting the nonlinear deformation characteristics of the seals caused by residual plastic deformation of the material in the low-pressure stage.

[0067] For example, in one embodiment, the maximum working pressure of the piston rod is 100 MPa, and the minimum first-level working pressure is 10 MPa. Based on the working conditions of the rubber-plastic seal, the pressure range is divided into a high-pressure stage, a medium-pressure stage, and a low-pressure stage. For the high-pressure stage, a step size factor of 0.5 is set, starting from 100 MPa, unloading 50% of the pressure each time, resulting in multiple first-level working pressures of 100 * 0.5 = 50 MPa for the high-pressure stage, until the calculated first-level working pressure reaches the maximum pressure of the medium-pressure stage. For the medium-pressure stage, the step size factor is adjusted to 0.8, starting from 50 MPa, resulting in a first-level working pressure of 50 * 0.80 = 40 MPa for the medium-pressure stage, until the calculated first-level working pressure reaches the maximum pressure of the low-pressure stage. For the low-pressure stage, the step size factor is adjusted to 0.9, starting from 32 MPa, resulting in a first-level working pressure of 32 * 0.9 = 28.8 MPa for the low-pressure stage, until the first-level working pressure is the same as the pressure at the unloading endpoint. The steps for implementing finite element simulation analysis of the second-direction motion under various first-level working pressures include:

[0068] (1) Determine the pressure value for each calculation cycle based on the typical working conditions of the piston rod simulation model;

[0069] Specifically, based on the typical operating conditions of the actual aviation hydraulic system simulated by the piston rod simulation model (such as the periodic operation state of alternating high and low pressure), the pressure values ​​corresponding to each calculation cycle are set. The pressure value of each calculation cycle is determined based on multiple first-level working pressures after gradual unloading, ensuring that the pressure conditions of each cycle closely match the low-pressure scenario in actual operation. It should be noted that one first-level working pressure corresponds to one calculation cycle.

[0070] (2) During each calculation cycle, apply the corresponding pressure value to the updated piston rod simulation model and drive the updated piston rod simulation model to perform at least one reciprocating stroke under the pressure value;

[0071] Specifically, within each calculation cycle, the pressure value corresponding to that cycle is applied to the updated piston rod simulation model, simultaneously driving the model to complete at least one reciprocating stroke (i.e., movement in the second direction) under that pressure. Through finite element simulation, data such as stress, strain, and contact pressure of the rubber-plastic seal are obtained during this process, capturing the performance response of the seal under specific low pressure reverse movement.

[0072] (3) Update the piston rod simulation model for the next calculation cycle based on the deformation parameters of the piston rod simulation model in the previous calculation cycle, and return to the step of applying the corresponding pressure value to the updated piston rod simulation model in the next calculation cycle.

[0073] Specifically, after completing the finite element simulation analysis of the previous calculation cycle, data on the rubber-plastic seal is extracted from the simulation results, including: element stress-strain data (elastic strain and plastic strain components) and the contact pressure distribution and contact area change between the rubber-plastic seal and contact components (such as piston rods and cylinders); based on the material constitutive relationship, the irreversible plastic strain is separated from the element stress-strain data, and its maximum value is taken as the plastic strain value; the area change of the region where the contact pressure is greater than the threshold is calculated; the accumulated amount of plastic strain and the rate of change of contact area in the previous calculation cycle are calculated, and the accumulated amount of plastic strain and the rate of change of contact area are used as the deformation parameters of the previous calculation cycle.

[0074] Specifically, based on the deformation parameters of the piston rod simulation model obtained from the previous calculation cycle (such as the deformation state of the seal, changes in material properties, etc.), the model for the next calculation cycle is updated to ensure that the model state continues the cumulative effects of the previous cycle (such as material fatigue, deformation superposition, etc.). Subsequently, the steps of applying the corresponding pressure value and driving the motion are repeated on the updated model to achieve multi-cycle continuous simulation.

[0075] By simulating the coupling effect of periodic pressure changes and reciprocating motion, the influence of the preceding cycle on the subsequent cycle is fully considered. This more realistically reproduces the continuous effect of alternating high and low pressure and bidirectional motion on rubber and plastic seals during long-term operation of the hydraulic system, providing reliable simulation data support for accurately analyzing the performance degradation law of the seals and evaluating their durability.

[0076] Furthermore, following simulation analyses under multiple first-level working stresses, the following was also included:

[0077] (1) Construct pressure-deformation curves based on the analysis results;

[0078] Specifically, based on the deformation data of different pressures (including the maximum working pressure and multiple first-level working pressures) and corresponding rubber and plastic seals obtained from finite element simulation analysis, the relationship curve between pressure and deformation is plotted with the working pressure as the abscissa and the deformation data as the ordinate, intuitively presenting the deformation response law of the seal during the pressure change process.

[0079] (2) Compare the error between the pressure-deformation curve and the actual curve;

[0080] Specifically, the constructed simulated pressure-deformation curve is compared with the pressure-deformation curve obtained through experiments or measurements under actual working conditions, and the error between the two is calculated.

[0081] Furthermore, using the pressure value as the abscissa, the same abscissa range is selected for both the simulated pressure-deformation curve and the actual pressure-deformation curve. Within this range, each first-level working pressure is taken as a node. For each node, the deformation value corresponding to that node is determined in both the simulated and actual pressure-deformation curves. The relative error between the simulated and actual deformation values ​​is calculated to obtain the error for each node.

[0082] (3) When the error is greater than the threshold, the initial parameters are reconfigured.

[0083] Specifically, for each node, the relationship between the relative error of each node and the threshold is determined. If, after comparison, it is found that the number of nodes with a relative error greater than the preset threshold exceeds the preset percentage, it indicates that there may be a deviation in the initial parameter settings (such as material parameters, geometric parameters, and actual seal characteristics not matching). In this case, the initial parameters of the rubber-plastic seal need to be readjusted (such as correcting the elastic modulus, adjusting the geometric dimensions, etc.), and the simulation model is reconstructed based on the new parameters, and the simulation analysis process is executed until the error of the pressure-deformation curve is within an acceptable range. It should be noted that the threshold and preset percentage are set according to actual needs, and are not limited in this embodiment.

[0084] By continuously improving the accuracy of the simulation model through closed-loop verification and parameter optimization, the final performance evaluation results of rubber and plastic seals are more closely related to reality, further ensuring the reliability of the performance analysis of rubber and plastic seals in aviation hydraulic products.

[0085] S106. Determine the deformation of the rubber-plastic seal based on the stress-strain results of multiple finite element simulation analyses in the second direction.

[0086] Specifically, in multiple finite element simulations, stress and strain data of the rubber-plastic seal during its second-direction movement under various first-level working pressures are obtained. These data directly reflect the stress and deformation state of the rubber-plastic seal under different low-pressure conditions and during reverse movement. By organizing and analyzing this data, information such as the degree of deformation, deformation location, and deformation trend of the rubber-plastic seal under different pressure conditions and during reverse movement can be tracked. This clarifies the specific variation law of its deformation with pressure changes and movement processes. For example, whether the deformation of the rubber-plastic seal shows a corresponding decrease or other specific changes when the pressure gradually decreases, and whether the deformation distribution shifts during reverse movement.

[0087] Furthermore, when determining the deformation changes of the rubber-plastic seal based on the stress-strain results of multiple finite element simulation analyses in the second direction, data such as strain values ​​and stress distribution characteristics of the rubber-plastic seal are extracted according to different first-level working pressures. The deformation and cumulative strain of each first-level working pressure are calculated, the deformation uniformity is analyzed, and the main deformation parts are located by combining the stress-strain distribution cloud map and tracking their transfer as the pressure decreases. The trend of deformation change with decreasing pressure and movement stroke position is determined. At the same time, the deformation data under the maximum working pressure is compared to evaluate the deformation recovery capacity and the residual influence of high-pressure plastic deformation on the deformation in the low-pressure stage. In this way, the deformation change law of the rubber-plastic seal in different low-pressure working conditions and reverse movement is clarified.

[0088] Furthermore, in the finite element simulation analysis process, the simulation workflow includes:

[0089] (1) Apply the maximum working pressure, and under the maximum working pressure, calculate the stress, strain and contact pressure of the piston rod simulation model moving in the first direction;

[0090] (2) The maximum working pressure is gradually unloaded to multiple first level working pressures according to the preset step size, and the stress, strain and contact pressure of the piston rod simulation model moving in the second direction under each first level working pressure are calculated respectively.

[0091] Specifically, the piston rod is first subjected to its maximum working pressure. Under this pressure condition, the piston rod simulation model is used to perform simulation calculations on its motion in the first direction. The focus is on obtaining stress and strain data of the model (especially the rubber and plastic seals) and the contact pressure between the seals and other components during this process. This stage aims to simulate the stress and contact state of the seals under extreme high-pressure conditions, providing basic data for subsequent analysis of the impact of high pressure on the seals.

[0092] Furthermore, after completing the high-pressure stage simulation, the working pressure is gradually unloaded from the maximum working pressure to multiple first-level working pressures (i.e., different low-pressure values) according to a preset step size (such as a fixed pressure reduction range). For each first-level working pressure, the stress, strain, and contact pressure of the piston rod simulation model when moving in a second direction opposite to the first direction are calculated. This stage, by simulating the gradual pressure reduction process and the reverse motion condition, comprehensively captures the performance response of the seal under the combined scenario of alternating high and low pressure and bidirectional motion, providing multi-dimensional simulation data for accurately analyzing its deformation and performance changes. Through the staged, variable-pressure, bidirectional motion simulation design, the high and low pressure alternating conditions in the actual operation of aviation hydraulic systems are more closely approximated, effectively making up for the shortcomings of existing technologies that only simulate single pressure or unidirectional motion.

[0093] S107. Determine the performance changes of the rubber-plastic seal during the piston reciprocating motion based on the input pressure of the piston rod simulation model and the deformation changes of the rubber-plastic seal.

[0094] Specifically, by performing finite element simulations of the updated piston rod simulation model under multiple first-level working pressures and second-direction motion, stress and strain data of the rubber-plastic seal were extracted in each simulation. This yielded the deformation changes of the rubber-plastic seal with pressure variations. The deformation changes included the degree of deformation (such as maximum deformation and cumulative strain) under different pressure conditions and during reverse motion, the deformation locations (such as the deformation positions of key areas like the sealing lip and the edge in contact with the cylinder), the deformation trends (such as the deformation variation law with decreasing pressure and the deformation distribution shift with the stroke), and the influence of high-pressure plastic deformation residue on the deformation in the low-pressure stage (such as deformation baseline offset).

[0095] Furthermore, the input pressure of the piston rod simulation model is correlated one-to-one with the deformation data of the rubber-plastic seal for each pressure, constructing a "pressure-deformation" correlation dataset. Based on the deformation data related to contact pressure, the degree of contact between the seal and the piston and cylinder is judged. If the contact pressure remains stable and within a reasonable range with the input pressure, it indicates reliable sealing contact; if the contact pressure drops sharply or falls below the threshold, it indicates a risk of leakage. Combining the maximum deformation, cumulative strain, and deformation uniformity data, it is assessed whether the rubber-plastic seal has suffered structural damage due to excessive deformation. If the deformation is always within the material's tolerance range and uniformly distributed, it indicates that the seal is reliable. The structure is stable; however, excessive local deformation or excessive accumulation of plastic strain may lead to permanent damage to the rubber and plastic seals. By comparing the deformation differences between the first direction of movement under high pressure and the second direction of movement under low pressure, the performance continuity of the rubber and plastic seals under alternating high and low pressure conditions is analyzed. If the deformation in the low-pressure stage can inherit the influence of high-pressure plastic deformation and maintain the sealing function, it indicates good adaptability. If abnormal deformation fluctuations occur (such as seal contact failure), it indicates performance defects. Based on the above analysis, the sealing performance, structural stability, and adaptability of the rubber and plastic seals under alternating high and low pressure conditions throughout the piston assembly process are comprehensively judged to clarify their performance change trend.

[0096] Specifically, changes in input pressure reflect the pressure conditions under different operating conditions during the piston's reciprocating motion (such as maximum working pressure and multiple first-level working pressures after gradual unloading), while the deformation changes of the rubber-plastic seal are reflected through the stress-strain results of multiple finite element simulations (including the maximum deformation in the first direction under high pressure and the deformation law in the second direction under low pressure). By correlating these two factors, the performance response of the seal under the combined effects of alternating pressure changes and bidirectional motion can be clarified. For example, by combining pressure values ​​with corresponding deformation, it can be determined whether the contact pressure of the seal under different pressures meets the sealing requirements (insufficient contact pressure may lead to leakage), whether the deformation is within the material's tolerance range (excessive deformation may cause permanent damage), and whether the cumulative deformation under alternating high and low pressures affects its long-term sealing performance and durability. Ultimately, through this correlative analysis, a comprehensive assessment of the key performance changes of the rubber-plastic seal, such as sealing performance, structural stability, and fatigue resistance, can be achieved throughout the piston assembly process, providing a basis for determining its suitability for the actual operating conditions of aviation hydraulic systems.

[0097] Figure 2 A schematic diagram illustrating the stress-strain state of a rubber-plastic seal, which is an exemplary embodiment of this application, is provided below. Figure 2Section OB represents the initial loading to low pressure after assembly, while section BC represents the initial loading from low to high pressure. Because plastic strain cannot be eliminated after the external load is unloaded, the material will deform along section CB' when the pressure alternates from high to low, instead of returning to the deformation state at point B. When the pressure alternates again from low to high, the plastic material will deform along... Figure 2 Deformation occurs in section B'C. At this point, due to the work hardening properties of the material, the yield strength has increased from point A to point C. Further pressurization will not cause additional plastic deformation. Therefore, the calculation of the high pressure input (or output) stroke can be performed when the high pressure is first applied, without affecting the calculation results.

[0098] Furthermore, after determining the performance changes of the rubber-plastic seal during the piston's reciprocating motion, the method further includes:

[0099] (1) Extract the deformation parameters of the rubber and plastic seals in each calculation cycle;

[0100] Specifically, in the finite element simulation analysis of multiple calculation cycles, the deformation parameters of the rubber and plastic seals are extracted in each cycle. These parameters can reflect the deformation characteristics of the seals under different pressure and motion states, such as maximum strain and changes in contact area.

[0101] (2) Plot the pressure-deformation curve based on the deformation parameters and the corresponding pressure;

[0102] Specifically, the deformation parameters extracted in each calculation cycle are correlated with the corresponding input pressure values, and a pressure-deformation curve is plotted with pressure on the horizontal axis and deformation parameters on the vertical axis. This curve visually presents the deformation pattern of the seal under different pressure conditions and clearly reflects the correspondence between pressure changes and deformation.

[0103] (3) Evaluate the sealing performance of the rubber-plastic seal based on the pressure-deformation curve.

[0104] Specifically, based on the plotted pressure-deformation curve, the sealing performance is assessed by analyzing the curve trend and key data. For example, if the curve shows that the contact pressure (related to the deformation parameter) of the seal remains stable and within a reasonable range within a certain pressure range, it indicates good sealing performance; if the curve shows that the contact pressure fluctuates too much with pressure changes, or even falls below the threshold required for sealing, there may be a risk of seal failure. In this way, the sealing reliability of rubber and plastic seals under different operating conditions during piston reciprocating motion can be effectively determined.

[0105] The piston rod rubber-plastic seal performance simulation analysis method provided in this embodiment constructs a piston rod simulation model containing the rubber-plastic seal based on the initial parameters of the rubber-plastic seal. Under the maximum working pressure, a finite element simulation of the piston rod simulation model in the first direction of motion is performed to determine the maximum deformation parameter. Then, the maximum plastic strain is calculated based on the maximum deformation parameter. Subsequently, the material parameters and geometric parameters of the seal are updated according to the maximum deformation parameter, and the piston rod simulation model is reassembled. Then, the pressure is gradually unloaded to multiple first-level working pressures, and a finite element simulation of the opposite second-direction motion is performed under each pressure. The performance change is determined by combining the input pressure and deformation change. Furthermore, the initial parameters are optimized by plotting the pressure-deformation curve and comparing it with the actual curve. Finally, the sealing performance of the rubber-plastic seal is evaluated based on the pressure-deformation curve. It fully simulates the actual working conditions of alternating high and low pressure in aviation hydraulic systems, and incorporates the influence of plastic deformation of rubber and plastic materials under high pressure on the subsequent low-pressure stroke. It solves the problem of distortion caused by single pressure simulation and neglect of the influence of high-pressure plastic deformation in existing technologies. It can truly reflect the stress, deformation and contact pressure changes of the seal under bidirectional motion and alternating pressure, and accurately evaluate its sealing performance, structural stability and durability throughout the assembly process. It provides a reliable basis for the design optimization, fault prediction and compatibility judgment of the seal.

[0106] Corresponding to the aforementioned embodiment of the performance simulation analysis method for rubber and plastic seals of piston rods, this application also provides an embodiment of a performance simulation analysis device for rubber and plastic seals of piston rods.

[0107] Figure 3 This is a schematic diagram of Embodiment 2 of the performance simulation analysis device for the piston rod rubber-plastic seal provided in this application. Please refer to... Figure 3 The apparatus provided in this embodiment includes a construction module 310, a simulation module 320, and a processing module 330; wherein,

[0108] The construction module 310 is used to obtain the initial parameters of the rubber and plastic seal and assemble a piston rod simulation model including the rubber and plastic seal according to the initial parameters.

[0109] The simulation module 320 is used to obtain the maximum working pressure of the piston rod, and under the maximum working pressure, to perform finite element simulation analysis of the piston rod simulation model in the first direction of motion.

[0110] The simulation module 320 is also used to determine the maximum deformation parameters of the piston rod simulation model based on the analysis results;

[0111] The simulation module 320 is also used to update the initial parameters of the rubber-plastic seal according to the maximum deformation parameter, thereby updating the piston rod simulation model;

[0112] The simulation module 320 is also used to gradually unload the working pressure to multiple first-level working pressures on the updated piston rod simulation model, and perform finite element simulation analysis on the second-direction motion under each first-level working pressure, wherein the second direction is opposite to the first direction.

[0113] The processing module 330 is used to determine the deformation of the rubber-plastic seal based on the stress-strain results of multiple finite element simulation analyses in the second direction.

[0114] The processing module 330 is also used to determine the performance changes of the rubber-plastic seal during the piston reciprocating motion based on the input pressure of the piston rod simulation model and the deformation changes of the rubber-plastic seal.

[0115] The apparatus of this embodiment can be used to perform... Figure 1 The steps of the method embodiment shown are similar in principle and process, and will not be repeated here.

[0116] The specific implementation process of the functions and roles of each unit in the above device can be found in the implementation process of the corresponding steps in the above method, and will not be repeated here.

[0117] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units 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 achieve the purpose of this application according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0118] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for simulation analysis of the performance of rubber-plastic seals for piston rods, characterized in that, The method includes: Obtain the initial parameters of the rubber and plastic seal, and assemble a piston rod simulation model including the rubber and plastic seal according to the initial parameters; Obtain the maximum working pressure of the piston rod, and perform finite element simulation analysis of the piston rod simulation model in the first direction under the maximum working pressure; The maximum deformation parameters of the piston rod simulation model were determined based on the analysis results. The initial parameters of the rubber-plastic seal are updated based on the maximum deformation parameter, thereby updating the piston rod simulation model; For the updated piston rod simulation model, the working pressure is gradually unloaded to multiple first-level working pressures. Finite element simulation analysis is performed on the second-direction motion under each first-level working pressure, where the second direction is opposite to the first direction. The unloading range of the working pressure is defined by taking the maximum working pressure as the starting point of the pressure unloading and the lowest first-level working pressure as the ending point. The unloading range is divided into stages according to multiple working conditions of the piston rod. For each stage, the corresponding first-level working pressure is calculated according to a preset step size coefficient. The deformation of the rubber-plastic seal is determined based on the stress-strain results of multiple finite element simulation analyses in the second direction. The performance changes of the rubber-plastic seal during the piston reciprocating motion are determined based on the input pressure of the piston rod simulation model and the deformation changes of the rubber-plastic seal. Specifically, the stress-strain data of the rubber-plastic seal in each simulation are extracted to obtain the deformation changes of the rubber-plastic seal with pressure. The deformation changes cover the degree of deformation, deformation location, deformation trend of the rubber-plastic seal under different pressure conditions and during the reverse motion, as well as the influence of high-pressure plastic deformation residue on the deformation in the low-pressure stage.

2. The method according to claim 1, characterized in that, The assembly of the piston rod simulation model, including the rubber-plastic seal, according to the initial parameters includes: The geometric and material parameters of the rubber and plastic seals are extracted based on the initial parameters. A three-dimensional model of the piston rod is created based on the geometric parameters; Based on the material parameters, the material properties of the 3D model are defined, and assembly is completed.

3. The method according to claim 1, characterized in that, Determining the maximum deformation parameter of the piston rod simulation model based on the analysis results includes: Define several key deformation parameters; Based on the analysis results, determine the parameter changes of each key deformation parameter between each key deformation parameter and the initial parameters; The values ​​of each key deformation parameter in the initial parameters are updated according to the changes in the parameters to obtain the maximum deformation parameter.

4. The method according to claim 1, characterized in that, The finite element simulation analysis of the second-direction motion under each first-level working pressure includes: The pressure values ​​for each calculation cycle are determined based on the typical working conditions of the piston rod simulation model. In each calculation cycle, a corresponding pressure value is applied to the updated piston rod simulation model, driving the updated piston rod simulation model to perform at least one reciprocating stroke under that pressure value; The piston rod simulation model for the next calculation cycle is updated based on the deformation parameters of the piston rod simulation model in the previous calculation cycle. In the next calculation cycle, the step of applying the corresponding pressure value to the updated piston rod simulation model is returned.

5. The method according to claim 1, characterized in that, The method further includes: Construct a pressure-deformation curve based on the analysis results; Compare the error between the pressure-deformation curve and the actual curve; When the error exceeds the threshold, the initial parameters are reconfigured.

6. The method according to claim 1, characterized in that, In the finite element simulation analysis process, the simulation workflow includes: Apply the maximum working pressure, and under the maximum working pressure, calculate the stress, strain, and contact pressure of the piston rod simulation model moving in the first direction; The maximum working pressure is gradually unloaded to multiple first-level working pressures according to a preset step size, and the stress, strain and contact pressure of the piston rod simulation model in the second direction are calculated for each first-level working pressure.

7. The method according to claim 1, characterized in that, After determining the performance changes of the rubber-plastic seal during piston reciprocating motion, the method includes: Extract the deformation parameters of the rubber and plastic seals in each calculation cycle; Plot the pressure-deformation curve based on the deformation parameters and the corresponding pressure; The sealing performance of the rubber-plastic seal is evaluated based on the pressure-deformation curve.

8. The method according to claim 1, characterized in that, The piston rod simulation model includes: The components include a rubber and plastic seal, a piston rod, and a cylinder. The rubber and plastic seal is in close contact with the piston rod and the cylinder, and the piston rod is connected to the cylinder.

9. The method according to claim 1, characterized in that, The initial parameters of the rubber-plastic seal are updated based on the maximum deformation parameters, which include maximum strain, maximum contact pressure, and maximum contact area; including: Calculate the maximum plastic strain of the rubber-plastic seal based on the maximum deformation parameter; The material and geometric parameters of the rubber-plastic seal are updated based on the maximum plastic strain. A simulation model of a piston rod, including updated rubber and plastic seals, is assembled based on material and geometric parameters.

10. A simulation analysis device for the performance of rubber and plastic seals on piston rods, characterized in that, The device includes a construction module, a simulation module, and a processing module; wherein... The construction module is used to obtain the initial parameters of the rubber and plastic seal and assemble a piston rod simulation model including the rubber and plastic seal according to the initial parameters. The simulation module is used to obtain the maximum working pressure of the piston rod, and under the maximum working pressure, to perform finite element simulation analysis of the piston rod simulation model in the first direction of motion. The simulation module is also used to determine the maximum deformation parameters of the piston rod simulation model based on the analysis results; The simulation module is also used to update the initial parameters of the rubber-plastic seal according to the maximum deformation parameter, thereby updating the piston rod simulation model; The simulation module is also used to gradually unload the working pressure to multiple first-level working pressures on the updated piston rod simulation model, and perform finite element simulation analysis on the second-direction motion under each first-level working pressure, wherein the second direction is opposite to the first direction. The processing module is used to determine the deformation of the rubber-plastic seal based on the stress-strain results of multiple finite element simulation analyses in the second direction. The processing module is also used to determine the performance changes of the rubber-plastic seal during the piston reciprocating motion based on the input pressure of the piston rod simulation model and the deformation changes of the rubber-plastic seal.

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