Simulation analysis method and device for performance of rubber and plastic sealing element of piston rod

Abstract

The invention provides a rubber and plastic sealing element performance simulation analysis method and device for a piston rod, and belongs to the technical field of rubber and plastic sealing element performance analysis. The method provided by the invention comprises the following steps: under the maximum working pressure, carrying out simulation analysis of first-direction movement; determining a maximum deformation parameter according to an analysis result; updating the piston rod simulation model according to the maximum deformation parameter; the working pressure is unloaded to a plurality of first horizontal working pressures, simulation analysis is conducted on second direction movement under the first horizontal working pressures, and the second direction is opposite to the first direction; determining the deformation change of the rubber and plastic sealing element according to multiple simulation analysis stress-strain results in the second direction; and determining the performance change of the rubber and plastic sealing element in the reciprocating motion process of the piston according to the input pressure of the piston rod simulation model and the deformation change of the rubber and plastic sealing element. The simulation analysis method and device for the performance of the rubber and plastic sealing element of the piston rod are used for accurately evaluating the performance of the rubber and plastic reciprocating sealing element in a typical aviation hydraulic product.

Description

Technical Field

[0001] The present application relates to the technical field of rubber and plastic seal performance analysis, and in particular to a method and device for simulating and analyzing the performance of a piston rod rubber and plastic seal. Background Art

[0002] Aviation hydraulic systems are widely used in key components of various aircraft, such as actuators, steering gear, and hydraulic oil 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. Their performance directly impacts the efficiency, durability, and safety of hydraulic systems. Therefore, accurately evaluating the performance of rubber and plastic seals under different operating conditions is crucial for system design, optimization, and fault prediction.

[0003] Existing finite element analysis methods are typically used to simulate the behavior of seals under hydraulic pressure during macroscopic finite element simulation analysis of rubber and plastic seals. Existing simulation methods typically assume a single pressure condition throughout the simulation, maintaining a constant pressure during both the extension and retraction strokes. The simulation model primarily infers the seal's performance by evaluating its stress, strain, and contact pressure under this single pressure. This method may be effective for analysis under a single pressure condition, but in real hydraulic systems, pressure often fluctuates periodically, and the alternating high and low pressure conditions significantly impact the seal.

[0004] First, the existing technology ignores the background working conditions of alternating high and low pressures, that is, the high-pressure and low-pressure stages in the reciprocating stroke during the simulation process are not properly distinguished, resulting in the calculation results only reflecting the sealing performance under a single pressure state, and failing to truly simulate the impact of the high-pressure alternation of the hydraulic system on the performance of rubber and plastic seals during actual operation. Secondly, the existing methods usually complete the calculation of the piston rod's out-stroke or in-stroke in the low-pressure stage, and ignore the effect of the plastic deformation of the plastic material after high-pressure loading. The effect of this plastic deformation in the low-pressure stage has not been fully considered, resulting in the low-pressure stroke not correctly reflecting the factors such as material hardening and deformation caused by high-pressure plastic deformation in the simulation, making it impossible to accurately evaluate the performance of the seal. Therefore, these two defects cause distortion of the simulation results, and it is impossible to effectively evaluate the long-term performance and durability of rubber and plastic seals under actual high- and low-pressure cycle conditions. Summary of the Invention

[0005] In view of this, the present application provides a method and apparatus for simulating and analyzing the performance of a rubber-plastic seal of a piston rod, so as to accurately evaluate the performance of a rubber-plastic reciprocating seal in a typical aviation hydraulic product.

[0006] Specifically, this application is implemented through the following technical solutions: A first aspect of the present application provides a performance simulation analysis method for a rubber-plastic seal of a piston rod, the method comprising: Acquiring initial parameters of the rubber-plastic seal, and assembling a piston rod simulation model including the rubber-plastic seal according to the initial parameters; Obtaining a maximum working pressure of the piston rod, and performing a finite element simulation analysis of movement in a first direction on the piston rod simulation model under the maximum working pressure; Determine the maximum deformation parameter of the piston rod simulation model according to the analysis results; Updating the initial parameters of the rubber-plastic seal according to the maximum deformation parameter, thereby updating the piston rod simulation model; For the updated piston rod simulation model, gradually unloading the working pressure to multiple first level working pressures, and performing finite element simulation analysis on the second direction movement under each first level working pressure, where the second direction is opposite to the first direction; Determining the deformation change of the rubber-plastic seal according to the stress-strain results of multiple finite element simulations in the second direction; The performance change of the rubber-plastic seal during the reciprocating motion of the piston is determined according to the input pressure of the piston rod simulation model and the deformation change of the rubber-plastic seal.

[0007] The second aspect of the present application provides a performance simulation and analysis device for a rubber and plastic seal of a piston rod, the device comprising a construction module, a simulation module and a processing module; wherein, The construction module is used to obtain initial parameters of the rubber-plastic seal and assemble a piston rod simulation model including the rubber-plastic seal according to the initial parameters; The simulation module is used to obtain the maximum working pressure of the piston rod, and perform a finite element simulation analysis of the piston rod simulation model moving in a first direction under the maximum working pressure; The simulation module is further used to determine the maximum deformation parameter of the piston rod simulation model according to the analysis results; The simulation module is further configured 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 further configured to gradually unload the working pressure of the updated piston rod simulation model to a plurality of first working pressure levels, and perform finite element simulation analysis on the movement in a second direction under each of the first working pressure levels, wherein the second direction is opposite to the first direction; The processing module is used to determine the deformation change of the rubber-plastic seal according to the stress-strain results of multiple finite element simulation analyses in the second direction; The processing module is further configured to determine a performance change of the rubber-plastic seal during the reciprocating motion of the piston according to the input pressure of the piston rod simulation model and the deformation change of the rubber-plastic seal.

[0008] The method and apparatus for simulating and analyzing the performance of a piston rod's rubber and plastic seal, provided in this application, consider the impact of the plastic deformation of the rubber and plastic seal after loading to maximum operating pressure on the low-pressure stroke of the next cycle during macroscopic finite element analysis of the piston rod, thereby accurately evaluating the performance changes of the rubber and plastic seal during the piston's reciprocating motion. First, a finite element simulation analysis of the piston rod simulation model is performed in a first direction at maximum operating pressure to determine the maximum deformation parameter and update the piston rod simulation model based on the maximum deformation parameter. The operating pressure is then gradually unloaded to multiple first-level operating pressures. At each first-level operating pressure, simulation analysis is performed for movement in a second direction opposite to the first direction. Finally, performance changes are determined by combining the input pressure and deformation changes. The actual working conditions of alternating high and low pressures are taken into consideration, and the first direction movement under high pressure and the second direction movement under low pressure are distinguished. The influence of the plastic deformation of the rubber and plastic material after high-pressure loading on the subsequent low-pressure stroke is fully incorporated, which solves the problem of result distortion caused by the simulation of a single pressure working condition and the 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 the rubber and plastic seals during the reciprocating motion of the piston. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a flow chart of Example 1 of the method for simulating and analyzing the performance of a rubber-plastic seal of a piston rod provided in this application; Figure 2 This is a schematic diagram showing the stress and strain state of a rubber-plastic seal according to an exemplary embodiment of the present application; Figure 3 This is a structural schematic diagram of Example 2 of the performance simulation and analysis device for the rubber and plastic seal of the piston rod provided in this application. DETAILED DESCRIPTION

[0010] Exemplary embodiments are described in detail herein, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numerals in different drawings represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with this application.

[0011] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a," "the," and "the" used in this application 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 or all possible combinations of one or more of the associated listed items.

[0012] 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 each other. 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 "at the time of" or "when" or "in response to determining".

[0013] Specific embodiments are given below to introduce the technical solutions of the present application in detail.

[0014] Figure 1 This is a flow chart of the first embodiment of the method for simulating and analyzing the performance of the rubber and plastic seal of the piston rod provided in this application. Figure 1 The method provided in this embodiment may include: S101 , obtaining initial parameters of a rubber-plastic seal, and assembling a piston rod simulation model including the rubber-plastic seal according to the initial parameters.

[0015] Specifically, rubber-plastic seals are sealing elements made of rubber or plastic, used to prevent fluid leakage. Their initial parameters 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 curve. These initial parameters can be obtained through material testing or from data provided by the supplier. It should be noted that the stress-strain curve is pre-derived from experiments and is used to characterize the plastic properties of the plastic in the rubber-plastic seal when subsequently constructing a piston rod simulation model.

[0016] Furthermore, the steps of assembling a piston rod simulation model including the rubber-plastic seal according to the initial parameters include: (1) Extracting geometric parameters and material parameters of the rubber and plastic seal according to the initial parameters; Specifically, the initial parameters of the rubber and plastic seals are separated into geometric parameters and material parameters. Geometric parameters include the shape, size, and other appearance characteristics of the rubber and plastic seals, such as inner diameter, outer diameter, thickness, and cross-sectional profile. Material parameters include the material properties of the rubber and plastic seals, such as elastic modulus, Poisson's ratio, density, hardness, and performance parameters unique to the rubber and plastic materials, such as temperature resistance and oil resistance.

[0017] (2) creating a three-dimensional model of the piston rod according to the geometric parameters; Specifically, based on the determined geometric parameters of the rubber-plastic seal, a piston rod simulation model including the rubber-plastic seal is constructed using 3D modeling software. The piston rod simulation model not only includes the geometric shape of the rubber-plastic seal, but can also accurately present the structure of related components such as the piston rod and cylinder body, ensuring that the size and relative position relationship of each component meet the actual assembly requirements, providing an accurate geometric basis for subsequent simulations.

[0018] (3) Defining the material properties of the three-dimensional model based on the material parameters to complete the assembly.

[0019] Specifically, based on the constructed piston rod simulation model, the material properties of the rubber and plastic seal in the piston rod simulation model are defined according to the determined material parameters, so that the piston rod simulation model can truly reflect the physical response of the rubber and plastic seal under stress and other conditions. After completing the material property definition, the piston rod, rubber and plastic seal, cylinder body and other components are virtually assembled according to the actual assembly relationship to form a complete piston rod simulation model.

[0020] Optionally, the piston rod simulation model includes: a rubber-plastic seal, a piston rod and a cylinder body, 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.

[0021] S102: Acquire a maximum working pressure of the piston rod, and perform a finite element simulation analysis of movement in a first direction on the piston rod simulation model under the maximum working pressure.

[0022] Specifically, the maximum operating pressure is determined based on the actual working conditions of the piston rod. Within the finite element analysis software, this maximum operating pressure is applied to the piston rod simulation model, driving it to move in a first direction. Note that this first direction can be either the extension or retraction direction of the piston rod. Using the finite element method, the stress, strain, contact pressure, and other data of the rubber and plastic seal during this process are calculated, focusing on the seal's deformation state, force distribution, and contact with other components under high pressure.

[0023] S103. Determine the maximum deformation parameter of the piston rod simulation model according to the analysis result.

[0024] Specifically, according to the analysis result of the piston rod simulation model under the maximum working pressure, the maximum deformation parameters (such as stress and strain) of the piston rod simulation model are extracted, which reflect the limit deformation state of the sealing element under high pressure.

[0025] Further, the implementation step of determining the maximum deformation parameters of the piston rod simulation model according to the analysis result comprises: (1) defining a plurality of key deformation parameters; Specifically, a plurality of key parameters reflecting the deformation characteristics of the piston rod simulation model are defined, and the key deformation parameters include the strain, contact pressure and contact area of the rubber-plastic sealing element, which are directly related to the sealing performance and structural stability of the sealing element.

[0026] (2) determining the parameter change of each key deformation parameter between the initial parameters and each key deformation parameter according to the analysis result; Specifically, based on the finite element simulation analysis result of the first direction movement under the maximum working pressure, the difference between each key deformation parameter and the initial parameter (i.e. the parameter reference value set before simulation) is calculated, that is, the parameter change. For example, the strain of the rubber-plastic sealing element in the initial parameter is 1, and the simulation analysis result shows that the actual strain of this part under the maximum working pressure is 3, so the parameter change of this key deformation parameter is 2.

[0027] (3) updating the numerical value of each key deformation parameter in the initial parameter according to the parameter change to obtain the maximum deformation parameter.

[0028] Specifically, the parameter change of each key deformation parameter obtained above is taken as an increase value, and the initial parameter is updated by summation, and the updated numerical value can truly reflect the limit deformation state of the piston rod simulation model under the maximum working pressure, that is, the maximum deformation parameter.

[0029] S104, updating the initial parameters of the rubber-plastic sealing element according to the maximum deformation parameters, thereby updating the piston rod simulation model.

[0030] Specifically, the maximum deformation parameters include the maximum strain, the maximum contact pressure and the maximum contact area, and the implementation step of updating the initial parameters of the rubber-plastic sealing element according to the maximum deformation parameters comprises: (1) calculating the maximum plastic strain of the rubber-plastic sealing element according to the maximum deformation parameters; Specifically, based on the maximum deformation parameter and the stress-strain data from the finite element simulation analysis results, the maximum plastic strain generated by the rubber and plastic seal under maximum operating pressure and motion in the first direction is calculated. Plastic strain is the permanent deformation of the material that cannot be recovered after being subjected to stress. It significantly affects the subsequent performance of the rubber and plastic seal (such as sealing and durability) and is the core basis for updating parameters.

[0031] (2) updating the material parameters and geometric parameters of the rubber-plastic seal according to the maximum plastic strain; Specifically, the initial parameters of the rubber-plastic seal are adjusted based on the calculated maximum plastic strain. Material parameter updates primarily address changes in material properties due to plastic deformation, such as hardening (changes in elastic modulus) and reduced toughness. Geometric parameter updates address permanent deformation of the seal due to plastic strain, such as changes in cross-sectional dimensions and contact profiles, ensuring the parameters reflect their true state after high pressure.

[0032] (3) Assemble the piston rod simulation model including the updated rubber-plastic seal according to the material parameters and geometric parameters.

[0033] Specifically, based on the updated material and geometric parameters, the rubber-plastic seal model was reconstructed and virtually assembled with other components, such as the piston rod and cylinder body, according to their actual assembly relationships, to form an updated piston rod simulation model. This model incorporates the effects of plastic deformation under high pressure, providing a more realistic foundation for subsequent second-direction motion simulation under low-pressure conditions and ensuring the consistency and accuracy of simulations of alternating high and low pressure conditions.

[0034] The maximum plastic strain of the rubber and plastic seal is calculated using the maximum deformation parameter, and the material parameters (such as material hardening and elastic modulus changes caused by plastic deformation) and geometric parameters (such as cross-sectional dimensions and contact profile changes caused by permanent deformation) of the rubber and plastic seal are updated accordingly. The piston rod simulation model is then reassembled to incorporate the irreversible effect of plastic deformation of the rubber and plastic material on the seal under the maximum working pressure condition. This allows the updated piston rod simulation model to truly reflect the state after the maximum working pressure acts, providing a realistic basis for subsequent simulation analysis under alternating high and low pressure conditions, ensuring the consistency and accuracy of the simulation from high-pressure to low-pressure stroke, and thereby improving the authenticity and reliability of the performance evaluation of rubber and plastic seals throughout the entire piston assembly process. This is particularly suitable for accurately simulating the performance of rubber and plastic reciprocating seals in aviation hydraulic systems under complex working conditions.

[0035] S105. For the updated piston rod simulation model, gradually unload the working pressure to multiple first-level working pressures, and perform finite element simulation analysis on the second-direction movement under each first-level working pressure, where the second direction is opposite to the first direction.

[0036] Specifically, starting from the maximum operating pressure, the operating pressure is gradually reduced to multiple preset first-level operating pressures using a stepwise unloading method. These first-level operating pressures have different pressure values. This allows for the diverse low-pressure conditions that may occur in actual hydraulic systems, more comprehensively simulating the effects of pressure fluctuations on rubber-plastic seals. It should be noted that the first-level operating pressure can be a low-pressure value under different operating conditions, or different pressure values ​​under the same operating condition; this is not a limitation in this embodiment.

[0037] At each first level of operating pressure, the piston rod simulation model is subjected to finite element simulation analysis of movement in a second direction opposite to the first (for example, if the first direction is piston rod extension, the second direction is piston rod retraction). This analysis provides stress and strain data for the seal under different low-pressure conditions and in reverse motion, including key information such as contact pressure changes and deformation degree.

[0038] Furthermore, the maximum working pressure is used as the starting point of pressure unloading, and the lowest first-level working pressure is used as the end point of pressure unloading to constitute the unloading range of the working pressure. The unloading range is divided into stages according to multiple working conditions of the piston rod, and the first-level working pressure corresponding to each stage is calculated according to the preset step coefficient.

[0039] Specifically, the maximum working pressure of the piston rod is used as the unloading starting point, and the lowest first-level working pressure (e.g., near zero pressure or the system's lowest operating pressure) is used as the unloading endpoint. The total range of pressure variation is clearly 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 deceleration 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 unloading in each stage, allowing the pressure to decrease at different rates in different stages. Based on the set stages and corresponding step size coefficients, the end-point pressure values ​​of each stage are calculated and used as multiple first-level working pressures to ensure that the pressure values ​​cover key nodes in the unloading process. It should be noted that the step size coefficients for each stage are set according to actual needs and can be the same or different. They are not limited in this embodiment. By simulating the non-uniform pressure variation characteristics of actual hydraulic systems: in the high-pressure range, the pressure may drop rapidly due to the rapid response of the system's unloading valve; in the low-pressure range, the unloading rate may be slowed 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 the nonlinear deformation characteristics of the seals in the low-pressure stage caused by the residual plastic deformation of the material.

[0040] For example, in one embodiment, the maximum working pressure of the piston rod is 100 MPa, and the lowest first-level working pressure is 10 MPa. The pressure range is divided into a high-pressure stage, a medium-pressure stage, and a low-pressure stage according to the working conditions of the rubber and plastic seal. For the high-pressure stage, the step coefficient is set to 0.5. Starting from 100 MPa, 50% of the pressure is unloaded each time, and the multiple first-level working pressures of the high-pressure stage are obtained as follows: 100*0.5=50 MPa, until the calculated first-level working pressure reaches the maximum pressure of the medium-pressure stage; for the medium-pressure stage, the step coefficient is adjusted to 0.8, starting from 50 MPa, the first-level working pressure of the medium-pressure stage is obtained as follows: 50*0.80=40 MPa, until the calculated first-level working pressure reaches the maximum pressure of the low-pressure stage; for the low-pressure stage, the step coefficient is adjusted to 0.9, starting from 32 MPa, the first-level working pressure of the low-pressure stage is obtained as follows: 32*0.9=28.8, until the first-level working pressure is the same as the pressure at the unloading end. The steps for implementing the finite element simulation analysis of the second direction movement under each first level working pressure include: (1) Determine the pressure value of each calculation cycle according to the typical working conditions of the piston rod simulation model; Specifically, the pressure values ​​corresponding to each calculation cycle are set based on the typical operating conditions of actual aviation hydraulic systems simulated by the piston rod simulation model (e.g., cyclical operation with alternating high and low pressures). The pressure values ​​for each calculation cycle are determined based on multiple first-level operating pressures after gradual unloading, ensuring that the pressure conditions in each cycle align with the low-pressure scenarios experienced in actual operation. It should be noted that each first-level operating pressure corresponds to one calculation cycle.

[0041] (2) in each calculation cycle, applying a corresponding pressure value to the updated piston rod simulation model, and driving the updated piston rod simulation model to perform at least one reciprocating stroke under the pressure value; Specifically, during each calculation cycle, the corresponding pressure value is applied to the updated piston rod simulation model, and the model is driven to complete at least one reciprocating stroke (i.e., movement in the second direction) under that pressure. Finite element simulation is used to obtain data such as stress, strain, and contact pressure of the rubber and plastic seal during this process, capturing the seal's performance response to reverse motion under specific low pressure.

[0042] (3) updating the piston rod simulation model for the next calculation cycle according to the deformation parameters of the piston rod simulation model in the previous calculation cycle, and returning to the step of applying the corresponding pressure value to the updated piston rod simulation model in the next calculation cycle.

[0043] Specifically, after completing the finite element simulation analysis of the last calculation period, the data of the rubber and plastic sealing element is extracted from the simulation results, including: unit stress and strain data (elastic strain, plastic strain component) and contact pressure distribution and contact area change of the rubber and plastic sealing element and the contact part (such as the piston rod, the cylinder); According to the unit stress and strain data based on the material constitutive relation, the non-recoverable plastic strain is separated from the unit stress and strain data, and the maximum value thereof is taken as the plastic strain value, and the area change of the region where the contact pressure is greater than the threshold value is calculated; The plastic strain accumulation and the contact area change rate in the last calculation period are calculated, and the plastic strain accumulation and the contact area change rate are taken as the deformation parameters of the last calculation period.

[0044] Specifically, the model of the next calculation period is updated based on the deformation parameters (such as the deformation state of the sealing element, the change of material performance, etc.) of the piston rod simulation model obtained by the last simulation, so that the model state continues the cumulative influence of the last period (such as material fatigue, deformation superposition, etc.). Then repeat the steps of applying the corresponding pressure value and driving the movement on the updated model to realize multi-period continuous simulation.

[0045] By simulating the coupling effect of periodic pressure change and reciprocating motion, the influence of the previous period on the subsequent period is fully considered, and the continuous effect of high and low pressure alternation and bidirectional motion on the rubber and plastic sealing element in the long-term operation of the hydraulic system is more truly restored, which provides reliable simulation data support for accurately analyzing the performance degradation law of the sealing element and evaluating its durability.

[0046] Further, after the simulation analysis under a plurality of first level working pressures, further comprising: (1) constructing a pressure-deformation curve according to the analysis results; Specifically, based on the deformation data of the rubber and plastic sealing element corresponding to different pressures (including the maximum working pressure and a plurality of first level working pressures) obtained by finite element simulation analysis, the working pressure is taken as the horizontal coordinate and the deformation data is taken as the vertical coordinate, the relationship curve between pressure and deformation is drawn, and the deformation response law of the sealing element in the pressure change process is intuitively presented.

[0047] (2) comparing the error between the pressure-deformation curve and the actual curve; Specifically, the simulation pressure-deformation curve constructed is compared with the pressure-deformation curve obtained by experiment or measurement in actual working condition, and the error between the two is calculated.

[0048] Furthermore, with the pressure value as the horizontal coordinate, the same horizontal coordinate range is selected for the simulated pressure-deformation curve and the actual pressure-deformation curve. Within the horizontal coordinate range, each first horizontal working pressure is regarded as a node. For each node, the deformation value corresponding to the node is determined in the simulated pressure-deformation curve and the actual pressure-deformation curve, and the relative error between the simulated deformation value and the actual deformation value is calculated to obtain the error of each node.

[0049] (3) When the error is greater than a threshold, reconfigure the initial parameters.

[0050] Specifically, for each node, the relationship between the relative error and the threshold is determined. If, after comparison, the number of nodes with relative errors exceeding the preset threshold exceeds a preset percentage, this indicates that the initial parameter settings may be biased (e.g., material parameters and geometric parameters do not match the actual seal characteristics). In this case, the initial parameters of the rubber-plastic seal need to be readjusted (e.g., correcting the elastic modulus, adjusting the geometric dimensions, etc.), and the simulation model is rebuilt 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.

[0051] Through closed-loop verification and parameter optimization, the accuracy of the simulation model is continuously improved to ensure that the final performance evaluation results of rubber and plastic seals are closer to reality, further guaranteeing the reliability of the performance analysis of rubber and plastic seals in aviation hydraulic products.

[0052] S106 , determining the deformation change of the rubber-plastic seal according to the stress-strain results of multiple finite element simulation analyses in the second direction.

[0053] Specifically, multiple finite element simulations will obtain stress and strain data for rubber and plastic seals during movement in the second direction at various first-level operating pressures. This data intuitively reflects the stress and deformation state of the rubber and plastic seals under different low-pressure conditions and during reverse movement. By organizing and analyzing this data, it is possible to track the degree of deformation, location of deformation, and deformation trend of the rubber and plastic seals under different pressure conditions and during reverse movement, and thus clarify the specific changes in their deformation with pressure changes and movement processes. For example, as the pressure gradually decreases, does the deformation of the rubber and plastic seal show a corresponding decrease or other specific changes, and whether the deformation distribution shifts during reverse movement.

[0054] Furthermore, when determining the deformation changes of rubber and plastic seals based on the stress and strain results of multiple finite element simulation analyses in the second direction, the strain values, stress distribution characteristics and other data of the rubber and plastic seals are extracted according to different first-level working pressure classifications, the deformation variables and strain accumulations of each first-level working pressure are calculated, the deformation uniformity is analyzed, and the main deformation parts are located in combination with the stress-strain distribution cloud map and their transfer as the pressure decreases. The changing trend of the deformation variables as the pressure decreases and the motion stroke position is determined, and the deformation data under the maximum working pressure are compared. The deformation recovery ability and the residual influence of high-pressure plastic deformation on the deformation in the low-pressure stage are evaluated, so as to clarify the deformation change law of rubber and plastic seals in different low-pressure working conditions and reverse motion.

[0055] Furthermore, during the finite element simulation analysis, the simulation process includes: (1) applying the maximum working pressure, and calculating the stress, strain, and contact pressure of the piston rod simulation model moving in the first direction under the maximum working pressure; (2) gradually unloading the maximum working pressure to a plurality of first level working pressures according to a preset step size, and calculating the stress strain and contact pressure of the piston rod simulation model moving in the second direction under each first level working pressure.

[0056] Specifically, the maximum operating pressure of the piston rod is first applied. Under this pressure, the piston rod simulation model is simulated in the first direction, focusing on obtaining stress and strain data of the model (especially the rubber and plastic seal) and the contact pressure between the seal and other components. This stage aims to simulate the stress and contact state of the seal under extreme high-pressure conditions, providing basic data for subsequent analysis of the impact of high pressure on the seal.

[0057] 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 amplitude). For each first-level working pressure, the stress, strain, and contact pressure of the piston rod simulation model are calculated when it moves in a second direction opposite to the first direction. This stage comprehensively captures the performance response of the seal in a complex scenario of alternating high and low pressures and bidirectional motion by simulating the process of gradual pressure reduction and the reverse motion conditions, providing multi-dimensional simulation data for accurate analysis of its deformation and performance changes. Through the staged, variable pressure, and bidirectional motion simulation design, it is closer to the high and low pressure alternating conditions in the actual operation of the aviation hydraulic system, effectively making up for the shortcomings of the single pressure or unidirectional motion simulation of the existing technology.

[0058] S107 , determining a performance change of the rubber-plastic seal during the reciprocating motion of the piston according to the input pressure of the piston rod simulation model and the deformation change of the rubber-plastic seal.

[0059] Specifically, by performing finite element simulation of the updated piston rod simulation model in the second direction motion under multiple first level working pressures, stress and strain data of the rubber plastic seal in each simulation are extracted, thereby obtaining deformation changes of the rubber plastic seal with pressure changes, which include deformation degree (such as maximum deformation amount and strain accumulation amount), deformation position (such as deformation position of key areas such as sealing lip and edge in contact with cylinder), deformation trend (such as deformation amount change law with pressure reduction, deformation distribution shift with motion stroke), and influence of high pressure plastic deformation residue on deformation in low pressure stage (such as deformation baseline offset) of the rubber plastic seal under different pressure working conditions and reverse motion process.

[0060] Further, the input pressure of the piston rod simulation model is one-to-one corresponding to the deformation change data of the rubber plastic seal corresponding to each pressure, a “pressure-deformation” correlation data set is constructed, and according to the deformation data related to the contact pressure, the fitting degree of the seal with the piston and the cylinder is judged. If the contact pressure remains stable with the change of the input pressure and is in a reasonable range, the sealing contact is reliable; if the contact pressure drops sharply or is lower than the threshold, it indicates that there is a risk of leakage; combined with the maximum deformation amount, strain accumulation amount and deformation uniformity data, whether the rubber plastic seal is damaged due to excessive deformation is evaluated. If the deformation is always within the material tolerance range and is uniformly distributed, it indicates that the structure is stable; if the local deformation is too large or the plastic strain accumulation exceeds the limit, it may cause permanent damage to the rubber plastic seal; by comparing the deformation difference between the first direction motion under high pressure and the second direction motion under low pressure, the performance continuity of the rubber plastic seal under high-low pressure alternating working conditions is analyzed. If the deformation in the low pressure stage can well inherit the influence of high pressure plastic deformation and maintain the sealing function, it indicates good adaptability; if there is abnormal fluctuation of deformation (such as sealing contact failure), it indicates that the performance is defective; based on the above analysis, the sealing performance, structural stability and adaptability of the rubber plastic seal under high-low pressure alternating working conditions in the whole process of piston assembly are comprehensively judged, and the performance change trend is determined.

[0061] Specifically, changes in input pressure reflect the pressure conditions under different operating conditions during the piston's reciprocating motion (such as maximum operating pressure and multiple first-level operating pressures after gradual unloading), while changes in the rubber and plastic seal's deformation are reflected through stress-strain results from multiple finite element simulations (including maximum deformation in the first direction under high pressure and deformation patterns in the second direction under low pressure). By correlating these two factors, the seal's performance response to the combined effects of alternating pressures and bidirectional motion can be clarified. For example, by combining pressure values ​​with corresponding deformation, it can be determined whether the seal's contact pressure under different pressures meets sealing requirements (inadequate contact pressure may lead to leakage), whether deformation is within the material's tolerance (excessive deformation may cause permanent damage), and whether the accumulated deformation under alternating high and low pressures affects its long-term sealing and durability. Ultimately, this correlation analysis enables a comprehensive assessment of key performance changes in the rubber and plastic seal, such as sealing performance, structural stability, and fatigue resistance, throughout the piston assembly process, providing a basis for determining its suitability for the actual operating conditions of aviation hydraulic systems.

[0062] Figure 2 The stress-strain state principle diagram of the rubber-plastic seal shown in the exemplary embodiment of this application is shown in FIG. Figure 2 OB section is the stage when the pressure is first loaded to low pressure after assembly, and BC section is the stage when the pressure is first loaded from low pressure to high pressure. Since plastic strain cannot be eliminated after the external load is unloaded, when the pressure alternates from high pressure to low pressure, the material will deform along CB' section and will not return to the deformed state at point B. When the pressure alternates from low pressure to high pressure again, the plastic material will deform along the following sections: Figure 2 Deformation occurs in the B'C section. At this time, due to the work-hardening characteristics of the material, the yield strength has increased from point A to point C. Re-pressurization will not cause additional plastic deformation. Therefore, the calculation of the high-pressure inlet (or outlet) stroke can be performed when the high pressure is first loaded, which has no effect on the calculation results.

[0063] Furthermore, after determining the performance change of the rubber-plastic seal during the reciprocating motion of the piston, the method further includes: (1) Extracting the deformation parameters of the rubber and plastic seal in each calculation cycle; Specifically, in the finite element simulation analysis of multiple calculation cycles, the deformation parameters of the rubber and plastic seal in each cycle are extracted respectively. These parameters can reflect the deformation characteristics of the seal under different pressures and motion states, such as maximum strain, contact area change, etc.

[0064] (2) drawing a pressure-deformation curve based on the deformation parameter and the corresponding pressure; Specifically, the deformation parameter extracted in each calculation period is associated with the corresponding input pressure value to draw a pressure-deformation curve with pressure as the horizontal axis and deformation parameter as the vertical axis. The curve intuitively presents the deformation law of the sealing element under different pressure conditions and clearly reflects the corresponding relationship between pressure change and deformation.

[0065] (3) evaluating the sealing performance of the rubber-plastic sealing element based on the pressure-deformation curve.

[0066] Specifically, based on the drawn pressure-deformation curve, the sealing performance is evaluated 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 sealing element remains stable and is in a reasonable range within a certain pressure range, it indicates that the sealing performance is good; if the curve shows that the contact pressure fluctuates too much with the change of pressure or even below the required threshold, there may be a risk of sealing failure. In this way, the sealing reliability of the rubber-plastic sealing element under different working conditions during the reciprocating motion of the piston can be effectively judged.

[0067] The performance simulation analysis method of the rubber-plastic sealing element of the piston rod provided in this embodiment is based on the initial parameters of the rubber-plastic sealing element to construct a piston rod simulation model containing the rubber-plastic sealing element, perform finite element simulation of the piston rod simulation model in the first direction motion under the maximum working pressure to determine the maximum deformation parameter, then calculate the maximum plastic strain according to the maximum deformation parameter, and then update the material parameters and geometric parameters of the sealing element according to the maximum deformation parameter and reassemble the piston rod simulation model, then gradually unload the pressure to a plurality of first level working pressures, perform finite element simulation of the second direction motion in the opposite direction under each pressure, determine the performance change by combining the input pressure and deformation change, and optimize the initial parameters by drawing the pressure-deformation curve and comparing with the actual curve. Finally, the sealing performance of the rubber-plastic sealing element is evaluated based on the pressure-deformation curve. The actual working conditions of the high and low pressure alternation of the aviation hydraulic system are fully simulated, the influence of the plastic deformation of the rubber-plastic material under high pressure on the subsequent low pressure stroke is taken into account, the distortion problem caused by the single pressure simulation and the neglect of the influence of high pressure plastic deformation in the prior art is solved, the stress, deformation and contact pressure change of the sealing element under the action of bidirectional motion and pressure alternation can be truly reflected, the sealing performance, structural stability and durability of the sealing element in the whole assembly process can be accurately evaluated, and reliable basis is provided for the design optimization, fault prediction and adaptability judgment of the sealing element.

[0068] Corresponding to the foregoing embodiment of the performance simulation analysis method of the rubber-plastic sealing element of the piston rod, the present application also provides an embodiment of a performance simulation analysis device of the rubber-plastic sealing element of the piston rod.

[0069] Figure 3 The structure schematic diagram of the second embodiment of the performance simulation analysis device of the rubber-plastic sealing element of the piston rod provided in the present application is shown in FIG. 2. Figure 3The device provided in this embodiment includes a construction module 310, a simulation module 320 and a processing module 330; wherein, The construction module 310 is used to obtain initial parameters of the rubber-plastic seal and assemble a piston rod simulation model including the rubber-plastic seal according to the initial parameters; The simulation module 320 is used to obtain the maximum working pressure of the piston rod, and perform a finite element simulation analysis of the piston rod simulation model moving in a first direction under the maximum working pressure; The simulation module 320 is further configured to determine the maximum deformation parameter of the piston rod simulation model based on the analysis results; The simulation module 320 is further configured 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 320 is further configured to gradually unload the working pressure of the updated piston rod simulation model to a plurality of first working pressure levels, and perform finite element simulation analysis on the movement in a second direction under each of the first working pressure levels, wherein the second direction is opposite to the first direction; The processing module 330 is used to determine the deformation change of the rubber-plastic seal according to the stress-strain results of multiple finite element simulation analyses in the second direction; The processing module 330 is further configured to determine a performance change of the rubber-plastic seal during the reciprocating motion of the piston according to the input pressure of the piston rod simulation model and the deformation change of the rubber-plastic seal.

[0070] The device of this embodiment can be used to perform Figure 1 The steps, specific implementation principles and implementation processes of the method embodiment shown are similar and will not be repeated here.

[0071] The implementation process of the functions and effects of each unit in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, and will not be repeated here.

[0072] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the partial description of the method embodiments. The device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0073] The above only is the preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A performance simulation analysis method for a piston rod rubber and plastic seal, characterized in that: The method comprises: Acquiring initial parameters of the rubber-plastic seal, and assembling a piston rod simulation model including the rubber-plastic seal according to the initial parameters; Obtaining a maximum working pressure of the piston rod, and performing a finite element simulation analysis of movement in a first direction on the piston rod simulation model under the maximum working pressure; Determine the maximum deformation parameter of the piston rod simulation model according to the analysis results; Updating the initial parameters of the rubber-plastic seal according to the maximum deformation parameter, thereby updating the piston rod simulation model; For the updated piston rod simulation model, gradually unloading the working pressure to multiple first level working pressures, and performing finite element simulation analysis on the second direction movement under each first level working pressure, where the second direction is opposite to the first direction; Determining the deformation change of the rubber-plastic seal according to the stress-strain results of multiple finite element simulations in the second direction; The performance change of the rubber-plastic seal during the reciprocating motion of the piston is determined according to the input pressure of the piston rod simulation model and the deformation change of the rubber-plastic seal.

2. The method according to claim 1, characterized in that The piston rod simulation model including the rubber-plastic seal is assembled according to the initial parameters; comprising: Extracting geometric parameters and material parameters of the rubber and plastic seal according to the initial parameters; Creating a three-dimensional model of the piston rod according to the geometric parameters; The material properties of the three-dimensional model are defined based on the material parameters to complete the assembly.

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

4. The method according to claim 1, wherein The finite element simulation analysis of the second direction movement under each first level working pressure includes: Determining the pressure value of each calculation cycle according to 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, and the updated piston rod simulation model is driven to perform at least one reciprocating stroke under the pressure value; The piston rod simulation model of the next calculation cycle is updated according to the deformation parameters of the piston rod simulation model in the previous calculation cycle. In the next calculation cycle, the process returns to the step of applying the corresponding pressure value to the updated piston rod simulation model.

5. The method according to claim 1, wherein The method further comprises: Construct a pressure-deformation curve based on the analysis results; comparing the error between the pressure-deformation curve and an actual curve; When the error is greater than a threshold, the initial parameters are reconfigured.

6. The method according to claim 1, characterized in that During the finite element simulation analysis, the simulation process includes: Applying the maximum working pressure, and calculating the stress, strain, and contact pressure of the piston rod simulation model moving in the first direction under the maximum working pressure; The maximum working pressure is gradually unloaded to a plurality of first level working pressures according to a 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.

7. The method according to claim 1, characterized in that After determining the performance change of the rubber-plastic seal during the reciprocating motion of the piston; the method includes: extracting deformation parameters of the rubber-plastic seal in each calculation cycle; Drawing a pressure-deformation curve according to the deformation parameter 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: 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.

9. The method according to claim 1, characterized in that The updating of the initial parameters of the rubber-plastic seal according to the maximum deformation parameters, wherein the maximum deformation parameters include maximum strain, maximum contact pressure, and maximum contact area, comprises: Calculating the maximum plastic strain of the rubber-plastic seal according to the maximum deformation parameter; Updating material parameters and geometric parameters of the rubber-plastic seal according to the maximum plastic strain; Assemble the piston rod simulation model including the updated rubber-plastic seal according to the material parameters and geometric parameters.

10. A performance simulation and analysis device for a piston rod rubber and plastic seal, characterized in that: The device includes a construction module, a simulation module and a processing module; wherein, The construction module is used to obtain initial parameters of the rubber-plastic seal and assemble a piston rod simulation model including the rubber-plastic seal according to the initial parameters; The simulation module is used to obtain the maximum working pressure of the piston rod, and perform a finite element simulation analysis of the piston rod simulation model moving in a first direction under the maximum working pressure; The simulation module is further used to determine the maximum deformation parameter of the piston rod simulation model according to the analysis results; The simulation module is further configured 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 further configured to gradually unload the working pressure of the updated piston rod simulation model to a plurality of first working pressure levels, and perform finite element simulation analysis on the movement in a second direction under each of the first working pressure levels, wherein the second direction is opposite to the first direction; The processing module is used to determine the deformation change of the rubber-plastic seal according to the stress-strain results of multiple finite element simulation analyses in the second direction; The processing module is further configured to determine a performance change of the rubber-plastic seal during the reciprocating motion of the piston according to the input pressure of the piston rod simulation model and the deformation change of the rubber-plastic seal.

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