A method and system for simulating the aging behavior of a household appliance wire harness

Abstract

The present application relates to the technical field of household appliance wire harness reliability testing, and particularly relates to a household appliance wire harness aging behavior simulation method and system. The method comprises the following steps: obtaining initial interface parameters of household appliance wire harness connection points to obtain wire harness interface data; performing heterogeneous interface modeling according to the wire harness interface data to obtain interface heterogeneous unit data; performing physical field coupling loading according to the interface heterogeneous unit data to obtain interface dynamic data; performing micro-motion wear and electrical-thermal aging correlation analysis on the interface dynamic data to obtain degradation characteristic data; performing acceleration loading adjustment according to the degradation characteristic data to obtain stage aging loading data; performing cyclic iteration aging evaluation according to the stage aging loading data to obtain aging behavior simulation results. The method can simultaneously simulate the micro-motion wear and electrical-thermal aging process of the wire harness connection points, extract coupled degradation characteristics and dynamically adjust the loading parameters, and improve the authenticity, acceleration and failure precursor identification accuracy of the aging behavior simulation.

Description

Technical Field

[0001] This invention relates to the field of reliability testing technology for household wiring harnesses, and in particular to a method and system for simulating the aging behavior of household wiring harnesses. Background Technology

[0002] Wiring harness connection points in home appliances are widely used in compressors, motors, control boards, power modules, heating modules, and sensor connection circuits. Their reliability directly affects the overall operational safety and long-term service stability of the appliance. Taking refrigerators, freezers, air conditioners, and washing machines as examples, wiring harness terminals, cold-pressed connections, soldered connections, and plug-in connections typically experience multiple factors simultaneously during operation, including current surges, temperature changes, mechanical vibrations, and ambient humidity and heat. Short-term vibrations or high-frequency micro-vibrations occur during compressor startup, washing machine spin-drying, and motor shifting. Furthermore, sudden changes in starting current or load can cause localized Joule heating at the connection points, placing the connection interface in a complex state of combined mechanical disturbance and electrothermal stress.

[0003] Existing methods for testing the aging of household wiring harnesses typically employ single-current aging, constant-temperature thermal aging, vibration testing, or continuity-lapse cycling testing to detect contact resistance, temperature rise, or mechanical holding force at wiring harness connection points. While these methods can reflect the aging trend under a single factor, they often treat mechanical vibration, contact wear, electrothermal temperature rise, and interface oxidation as independent degradation processes, making it difficult to accurately simulate the degradation chain in actual service life. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a method and system for simulating the aging behavior of household electrical wiring harnesses, thereby resolving at least one of the aforementioned technical issues.

[0005] This application provides a method for simulating the aging behavior of household electrical wiring harnesses, including the following steps: Obtain the initial interface parameters of the home appliance wiring harness connection points to obtain the wiring harness interface data; Heterogeneous interface modeling is performed based on the wire harness interface data to obtain interface heterogeneous unit data; Physical field coupling loading is performed based on the interface heterogeneous unit data to obtain the interface dynamic data; Correlation analysis between fretting wear and electrothermal aging was performed on the dynamic data of the interface to obtain degradation characteristic data; Accelerated loading is adjusted based on degradation characteristic data to obtain staged aging loading data; Based on the stage aging loading data, iterative aging assessments are performed to obtain aging behavior simulation results.

[0006] This invention uses the initial interface parameters of household wire harness connection points as a foundation. First, it constructs heterogeneous interface units capable of characterizing the different states of the crimping area and the plating contact area. Then, through physical field coupling loading, it synchronously simulates the combined effects of vibration fretting, current surges, and localized temperature rises on the connection interface, avoiding the problem that traditional single vibration tests or single electrothermal aging tests cannot accurately reproduce the actual service degradation path. By performing correlation analysis between fretting wear and electrothermal aging on the interface dynamic data, early degradation characteristics such as contact pressure attenuation, contact resistance jumps, and heat concentration expansion can be identified. Based on the degradation characteristics, the stage loading parameters are adaptively adjusted, enabling the aging process to both accelerate and maintain consistency with the actual failure mechanism, thereby improving the accuracy, repeatability, and failure precursor identification capability of household wire harness aging behavior simulation.

[0007] Preferably, heterogeneous interface modeling specifically involves: The interface data of the wire harness is analyzed to obtain the interface structure partition data; the material contact relationship is identified based on the interface structure partition data to obtain the heterogeneous material contact data; the interface physical property parameters are assigned based on the heterogeneous material contact data to obtain the interface physical property parameter data; the micro-contact units are discretized based on the interface physical property parameter data to obtain the interface micro-contact unit data; and the heterogeneous interface units are integrated based on the interface micro-contact unit data to obtain the interface heterogeneous unit data.

[0008] This invention analyzes the connection region structure of the wire harness interface data, subdividing the originally monolithically described connection points into specific structural regions such as the crimping area, plating contact area, and edge transition area, thereby improving the spatial resolution of subsequent aging simulations. By identifying material contact relationships and assigning interface property parameters, differences in contact resistance, thermal conductivity, elastic modulus, and coefficient of thermal expansion under different material combinations can be incorporated into the model, avoiding the error of equating heterogeneous interfaces with uniform contact surfaces. Through micro-contact unit discretization and heterogeneous interface unit integration, the detailed response of local contact points and the conduction relationship of the overall interface can be preserved simultaneously, providing accurate interface baseline data, thus improving the realism and interpretability of wire harness aging behavior simulation.

[0009] Preferably, the physical field coupling loading specifically refers to: The interface heterogeneous unit data is loaded with boundary conditions to obtain coupled loading boundary data; the coupled loading boundary data is subjected to high-frequency micro-amplitude vibration loading to obtain interface vibration loading data; the interface vibration loading data is subjected to pulse current loading to obtain interface electrothermal loading data; the interface electrothermal loading data is corrected by thermo-mechanical feedback to obtain interface coupling correction data; the interface coupling correction data is dynamically sampled and integrated to obtain interface dynamic data.

[0010] In this invention, by first configuring loading boundary conditions, the constraint states, conductive paths, heat dissipation boundaries, and vibration directions of heterogeneous units at different interfaces can be uniformly defined, avoiding simulation deviations caused by inconsistent boundary conditions during coupled loading. Further application of high-frequency micro-amplitude vibrations and pulsed currents can synchronously reproduce the fretting wear and local Joule heating effects caused by compressor start-up and shutdown, dehydration vibrations, and transient current impacts during appliance operation. Through thermo-mechanical feedback correction, the thermal expansion, contact pressure changes, and contact resistance changes caused by temperature rise can be reversed and applied to the interface state, making the simulation process closer to the real degradation chain. Finally, dynamic sampling and integration form dynamic interface data, providing continuous and traceable multiphysics response data for subsequent implementation.

[0011] Preferably, the correlation analysis between fretting wear and electrothermal aging is as follows: The dynamic data of the interface is time-series aligned to obtain synchronized interface data. Based on the synchronized interface data, fretting wear features and electrothermal aging features are extracted to obtain fretting wear feature data and electrothermal aging feature data, respectively. Based on the fretting wear feature data and electrothermal aging feature data, coupling correlation calculation is performed to obtain coupled correlation feature data. Based on the coupled correlation feature data, degradation identification is performed to obtain degradation feature data.

[0012] This invention achieves time-series alignment of interface dynamic data, unifying data from different sampling sources such as vibration response, current pulses, temperature rise changes, and contact resistance fluctuations under the same time reference, thus avoiding misjudgments caused by signal lag or sampling frequency differences. By extracting fretting wear features and electrothermal aging features separately, degradation factors such as mechanical contact relaxation, sudden contact resistance jumps, localized heat concentration, and oxide film growth can be characterized in layers. Through coupled correlation calculations, the dynamic causal relationship between fretting wear and increased contact resistance, and electrothermal concentration and accelerated interface aging, can be identified. The system obtains degradation identifiers, enabling aging states to move beyond single threshold judgments and output degradation feature data with temporal, spatial, and mechanistic orientations, improving the accuracy and interpretability of failure precursor identification.

[0013] Preferably, the fretting wear feature extraction specifically involves: Based on the interface synchronization data, contact pressure attenuation processing and contact resistance jump processing are performed to obtain first fretting wear characteristic data and second fretting wear characteristic data; spatial overlap identification is performed on the first fretting wear characteristic data and second fretting wear characteristic data to obtain fretting wear spatial data; multidimensional degradation characterization fusion is performed on the fretting wear spatial data to obtain characterization fusion data; wear state spectrum mapping is performed based on the characterization fusion data to obtain fretting wear characteristic data.

[0014] This invention extracts precursors of fretting wear from both mechanical contact stability and electrical contact continuity by separately processing contact pressure attenuation and contact resistance jumps, avoiding missed detections due to reliance on a single pressure or resistance threshold. Spatial overlap identification of the first and second fretting wear feature data allows for determination of whether the pressure attenuation region and the resistance anomaly region occur on the same interface heterogeneous unit or adjacent conduction paths, thus locating the actual active wear region. Multidimensional degradation characterization fusion unifies parameters such as pressure attenuation rate, resistance jump amplitude, duration, and spatial overlap, improving the stability of fretting wear state identification. Wear state spectrum mapping outputs fretting wear feature data with type attribution and evolutionary direction.

[0015] Preferably, the contact pressure attenuation treatment specifically includes: The compressor start / stop window is captured from the interface synchronization data to obtain start / stop interface data; a heterogeneous unit pressure baseline is constructed based on the start / stop interface data to obtain unit pressure baseline data; phase-related pressure decay is identified based on the unit pressure baseline data and the start / stop interface data to obtain phase pressure decay data; thermal expansion disturbances are eliminated based on the phase pressure decay data to obtain irreversible pressure decay data; pressure migration path is identified based on the irreversible pressure decay data to obtain first fretting wear characteristic data.

[0016] This invention, by capturing the compressor start-up and shutdown window, limits the contact pressure attenuation analysis to typical operating conditions involving both transient high current and short-term vibration shocks, avoiding the inclusion of normal pressure fluctuations during stable operation. By constructing a heterogeneous unit pressure baseline, the initial pressure states of different regions, such as the press-fit area and the coating contact area, can be characterized, improving the accuracy of local attenuation identification. Combining vibration phase with pressure attenuation identification allows for locating the correspondence between pressure drop and start-up / shutdown shocks; thermal expansion disturbance elimination distinguishes between recoverable thermal expansion fluctuations and irrecoverable contact relaxation. Finally, identifying the pressure migration path reflects contact point redistribution and active areas of early fretting wear, providing more mechanistic-oriented first fretting wear characteristic data for subsequent degradation analysis.

[0017] Preferably, the contact resistance jump treatment specifically includes: Contact resistance sequence is extracted from interface synchronization data to obtain interface resistance time-series data; a resistance baseline is constructed based on the interface resistance time-series data to obtain contact resistance baseline data; contact conduction transient instability is captured based on the contact resistance baseline data and interface resistance time-series data to obtain resistance jump data; vibration phase and current pulse correlation verification is performed based on the resistance jump data to obtain resistance jump correlation data; and jump feature identification is performed based on the resistance jump correlation data to obtain second fretting wear feature data.

[0018] This invention extracts contact resistance sequences from interface synchronous data and constructs a resistance baseline, enabling the differentiation between slow resistance changes at harness connection points under normal energization and temperature rise drift, and transient abnormal changes caused by fretting wear. By employing contact conduction transient instability capture, early instability phenomena such as short-term resistance jumps, discontinuous conductive paths, and local contact point migrations can be located from interface resistance time-series data, avoiding the masking of anomalies caused by evaluating only average contact resistance. Through vibration phase and current pulse correlation verification, it can be determined whether resistance jumps correspond to micro-amplitude vibration peaks, commutation stages, or pulse current impacts, thereby improving the reliability of anomaly source determination. The system obtains second fretting wear characteristic data, providing a characteristic basis for identifying fretting wear of unstable electrical contact types.

[0019] Preferably, the accelerated loading adjustment specifically includes: The degradation rate is identified from the degradation characteristic data to obtain degradation rate assessment data; the loading safety boundary is determined based on the degradation rate assessment data to obtain loading boundary constraint data; the vibration loading parameters are adjusted based on the loading boundary constraint data to obtain vibration adjustment parameter data; the electrothermal loading parameters are adjusted based on the loading boundary constraint data and the vibration adjustment parameter data to obtain electrothermal adjustment parameter data; and a staged loading scheme is generated based on the vibration adjustment parameter data and the electrothermal adjustment parameter data to obtain staged aging loading data.

[0020] This invention identifies the degradation rate by analyzing degradation characteristic data, enabling real-time determination of whether the wiring harness connection interface is in a stable degradation, accelerated degradation, or critical failure stage, thus avoiding distortion of the aging process caused by fixed loading parameters. By determining the loading safety boundary, it improves the efficiency of accelerated testing while preventing unrealistic burnouts caused by excessive temperature rise, large resistance jumps, or abnormal contact loosening. By adjusting the vibration loading parameters and electrothermal loading parameters separately, the intensity of micro-vibration, pulse current density, and loading interval can dynamically change with the degradation state, more closely resembling the actual start-stop and load fluctuation conditions of household appliances. Finally, it generates staged aging loading data, enabling control of degradation identification, parameter adjustment, and staged loading, improving the acceleration, controllability, and consistency of failure paths in aging simulation.

[0021] Preferably, the cyclic iterative aging assessment specifically includes: The stage aging loading data is used to perform cyclic loading to obtain stage cyclic data; the stage cyclic data is updated with degradation trajectory to obtain harness degradation trajectory data; stage failure precursor identification is performed based on harness degradation trajectory data to obtain failure precursor data; cyclic termination iteration is determined based on failure precursor data to obtain aging iteration determination data; failure mode evaluation is performed based on aging iteration determination data and harness degradation trajectory data to obtain aging behavior simulation results.

[0022] This invention utilizes cyclic loading based on staged aging loading data to enable continuous and observable degradation responses at the wiring harness connection points under multiple rounds of vibration and electrothermal coupling conditions, rather than relying on a single loading result. By updating the degradation trajectory of the staged cyclic data, changes in contact resistance, temperature rise, pressure decay, fretting wear, and hot spot evolution can be continuously recorded, forming a traceable aging path. Stage failure precursor identification can detect critical changes such as continuously rising resistance, abnormally amplified temperature rise, and rapid decrease in contact pressure in advance. Cyclic termination iteration determination can prevent overloading leading to unrealistic failures. Combining aging iteration determination data and wiring harness degradation trajectory data for failure mode assessment can more accurately distinguish between different aging behaviors such as fretting wear-dominated, electrothermal aging-dominated, or combined coupling failures, improving the engineering interpretation value of the simulation results.

[0023] Preferably, this application also provides a home wiring harness aging behavior simulation system for performing the home wiring harness aging behavior simulation method described above, the home wiring harness aging behavior simulation system comprising: The interface parameter acquisition module is used to acquire the initial interface parameters of the home appliance wiring harness connection points and obtain the wiring harness interface data. The heterogeneous interface modeling module is used to perform heterogeneous interface modeling based on the wire harness interface data to obtain interface heterogeneous unit data. The physical field coupling loading module is used to perform physical field coupling loading based on the interface heterogeneous unit data to obtain interface dynamic data. The degradation feature extraction module is used to perform correlation analysis between micro-motion wear and electrothermal aging on interface dynamic data to obtain degradation feature data; The staged aging loading module is used to adjust the accelerated loading based on degradation characteristic data to obtain staged aging loading data. The aging behavior simulation module is used to perform iterative aging assessments based on stage aging loading data to obtain aging behavior simulation results.

[0024] The beneficial effects of this invention are as follows: By obtaining the initial interface parameters of the connection points of household wire harnesses, the basic state of the connection interface, such as the crimping area and the plating contact area, can be established first, providing accurate initial boundaries for subsequent aging simulation. Through heterogeneous interface modeling, the originally monolithic wire harness connection points are divided into interface heterogeneous units with different electrical, thermal, and mechanical properties, allowing degradation behaviors such as fretting wear, electrothermal aging, and contact relaxation to be characterized at the local interface scale. Subsequently, physical field coupling loading is performed based on the interface heterogeneous units, which can simultaneously simulate the combined effects of high-frequency micro-amplitude vibration, pulse current impact, and local temperature rise on the connection interface, avoiding the problem that traditional single vibration tests or single thermal aging tests cannot accurately reproduce the actual service failure path. By performing correlation analysis between fretting wear and electrothermal aging on the interface dynamic data, degradation characteristics such as contact pressure attenuation, contact resistance jumps, and heat concentration expansion can be extracted, and the coupling influence relationship between the two can be identified. Accelerated loading adjustment is performed according to the degradation characteristics, allowing the vibration loading parameters and electrothermal loading parameters to dynamically change with the degradation state, improving the efficiency of aging simulation while avoiding unrealistic failures caused by overloading. By generating aging behavior simulation results through iterative aging assessment, the development process of household wiring harness connection points from initial stability and local degradation to pre-failure signs can be accurately represented, thereby improving the authenticity, repeatability, and engineering interpretation value of aging assessment. Attached Figure Description

[0025] Other features, objects, and advantages of this application will become more apparent from the following detailed description of the non-limiting embodiments, taken with reference to the accompanying drawings: Figure 1 A flowchart illustrating the steps of a method for simulating the aging behavior of household electrical wiring harnesses according to an embodiment is shown. Figure 2 A flowchart illustrating the steps of a heterogeneous interface modeling method according to one embodiment is shown. Figure 3 A flowchart illustrating the steps of a physical field coupling loading method according to an embodiment is shown. Figure 4 A flowchart illustrating the steps of a method for analyzing the correlation between fretting wear and electrothermal aging according to an embodiment is shown. Figure 5 A flowchart illustrating the steps of an embodiment of an accelerated loading adjustment method is shown. Figure 6 A flowchart illustrating the steps of an embodiment of a cyclic iterative aging assessment method is shown. Detailed Implementation

[0026] The technical method of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. Functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor methods and / or microcontroller methods.

[0028] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] The terminal connection point of a refrigerator compressor wiring harness was selected as the aging simulation object, and the wire specification was 0.75mm. 2 The terminal material is copper alloy tin-plated terminals, with initial contact resistance... Initial interface temperature rise Effective contact width Surface roughness Contact protrusion height The system establishes a heterogeneous interface model containing 520 micro-contact units based on the above parameters, and operates at rated current. compressor main vibration frequency Ambient temperature Ambient humidity Physical field coupling loading is performed under certain conditions.

[0030] In the comparative embodiment, only the traditional aging simulation method with fixed current and fixed temperature was used, without distinguishing between effective contact units, weak contact units, and gap units, and without introducing the coupling analysis of fretting wear and electrothermal aging. After 120 hours of simulation, the traditional method only outputs the overall contact resistance as... Growth to The system could not locate the concentrated degradation area; however, when using the method of this application, the system identified 86 out of 520 micro-contact units as weak contact units, with a weak contact ratio of 16.5%. Among them, 43 units were marked as wear-electrothermal coupling degradation units and located in the edge area of ​​the terminal mating contact area.

[0031] In the cyclic iterative aging assessment, when the cumulative aging loading time reaches 146 hours, the system predicts that the increase in contact resistance will reach [a certain value]. That is, the total contact resistance is approximately The initial contact resistance increased by approximately 53.8%, with the highest local temperature reaching 72.4℃, and the proportion of weak contacts reaching 20.2%, meeting the criteria for weak contact propagation failure. Accelerated aging tests verified that the same specification wire harness sample exhibited failure with a contact resistance increase exceeding 50% after approximately 152 hours, a deviation of approximately 3.9%. Compared to the approximately 18.6% failure time prediction deviation of traditional fixed-load simulation methods, the method in this application reduces the prediction deviation to less than 5%.

[0032] Therefore, this embodiment, through initial interface parameter modeling, micro-contact unit division, vibration-current-thermal field coupling loading, and degradation feedback-based accelerated loading adjustment, can elevate the aging simulation results from overall resistance changes to unit-level degradation path identification. This allows for the quantification and output of weak contact expansion locations, contact resistance growth rates, local temperature rise peaks, and failure occurrence times. In the above embodiment, this method reduces the failure time prediction error by approximately 14.7 percentage points and identifies 43 high-risk coupled degradation units at the terminal edge in advance, improving the positioning accuracy and reliability of aging behavior simulation for household wiring harness connection points.

[0033] Please see Figures 1 to 6 This application provides a method for simulating the aging behavior of household wiring harnesses, including the following steps: S1. Obtain the initial interface parameters of the home appliance wiring harness connection point and get the wiring harness interface data; Specifically, after the household wiring harness is assembled, the crimping area of ​​the plug-in terminal, the terminal mating contact area, and the transition area of ​​the wire insulation layer are selected as the connection point sampling areas. The initial contact resistance is obtained using a contact-type micro-ohmmeter. The initial insertion force is obtained by using a terminal insertion and extraction force tester. and pull-out force The roughness of the terminal contact surface is obtained by a three-dimensional profilometer. Contact protrusion height and effective contact width The interface temperature rise after stabilization is obtained by infrared thermometry or thermocouples. Record the wire specifications at the same time. Terminal material type Coating thickness crimping height crimping width and ambient temperature Ambient humidity .

[0034] S2. Based on the wire harness interface data, perform heterogeneous interface modeling to obtain interface heterogeneous unit data; Specifically, depending on the type of terminal material Coating thickness Wire specifications crimping height and crimp width A local 3D model of the connection point is established and divided into conductor core wire units, terminal substrate units, plating units, contact bump units, and insulation transition units. This is based on the terminal material type. First, retrieve the geometric constraints and material properties of the corresponding terminal substrate, such as the elastic modulus, Poisson's ratio, and conductivity for copper alloy terminals; then, based on the wire specifications... Determine the equivalent cross-sectional area of ​​the conductor core and the outer diameter of the core bundle, and use this outer diameter as the conductor filling boundary of the crimping zone. Based on the crimping height... and crimp width The outer contour of the crimping area is constructed, that is, the terminal crimping wing, conductor core wire, and insulation layer transition section are confined within the corresponding height and width envelope, forming the basic geometric framework of the connection point. After the basic geometric framework is formed, the terminal substrate area is used as the carrier layer, the conductor core wire area as the conductive filler layer, and the conductor insulation layer transition area as the non-conductive covering layer. Then, based on the plating thickness... A thin layer structure is formed by offsetting outwards or inwards along the terminal mating contact surface and the inner surface of the crimping, so that the thin layer covers the surface of the terminal substrate as a plating unit. This is based on the effective contact width. Determine the modeling boundary of the terminal mating contact surface based on the height of the contact protrusion. and roughness The contact surface is discretized using micro-protrusions. For the mating contact area, a local undulating surface is formed on the coating surface based on the height and roughness of the contact protrusions, which is higher than... The mesh is divided into contact bump elements, and areas that do not reach the contact reference surface are retained as gaps or non-contact areas. That is, for the j-th surface mesh, if its local height... satisfy: If the contact resistance is positive, the mesh is marked as a valid contact element; otherwise, it is marked as a gap element. This is based on the initial contact resistance. Assign initial resistance properties to effective contact units based on interface temperature rise. Assign an initial thermal state, based on the insertion force and pull-out force Set the contact clamping boundary and holding force boundary to form the interface heterogeneous element data: ,in Geometric mesh data, This data represents the material layering, including conductor core units, terminal substrate units, plating units, contact bump units, and insulation transition units. Mark the contact / gap data.

[0035] S3. Perform physical field coupling loading based on the interface heterogeneous unit data to obtain interface dynamic data; Specifically, the effective contact unit is used as the current-passing area, and the gap unit is used as the high-resistance isolation area. This is based on the rated operating current of the household wiring harness. Alternatively, a preset aging loading current I(t) can be applied to the effective contact unit as a current boundary; for the j-th effective contact unit, its initial electrothermal source can be expressed as: ,in For the current allocated to the j-th effective contact unit, Let be the contact resistance of this unit at the current moment, and initially satisfy . Source Unitized allocation. Based on interface temperature rise. Set the initial thermal field to As the initial temperature of the contact area, the ambient temperature As the outer boundary temperature, with ambient humidity As a boundary parameter for oxidation or damp heat aging. Based on material layering data. The thermal conductivity, electrical conductivity, and coefficient of thermal expansion are respectively assigned to the terminal substrate, plating, conductor core, and insulation transition zone. These parameters are obtained by querying a pre-stored material parameter database. (Based on insertion force) Set the initial clamping load after terminal engagement, based on the pull-out force. Set connection retention force constraint; local contact pressure Below the preset holding pressure limit When the effective contact element is converted into a weak contact element, the element area of ​​the j-th effective contact element is: If the effective contact unit set is ,but: The lower limit of pressure is expressed as: ,in To maintain the force reduction factor, used to indicate that not all pull-out force is converted into interface normal contact pressure, it is taken as 0.35. Local contact pressure. It is based on the normal clamping force of the j-th effective contact unit. Divide by unit area The calculated normal clamping force Calculation method: ,in Let J be the equivalent contact stiffness corresponding to the j-th contact element. This represents the change in normal displacement of the unit due to temperature variations, compression deformation, or fretting. The initial normal clamping force is expressed as: ,in This is a direction correction factor for the conversion of the insertion force into the contact normal pressure, used to indicate that the insertion force does not act entirely perpendicularly to the contact surface. For common plate terminals or spring terminals, it is taken as 0.45. The equivalent contact stiffness is expressed as: ,in The equivalent thickness of the terminal substrate participating in local elastic compression. For coating thickness, The equivalent thickness of the conductor core or the material on the opposite side of the contact participating in local elastic compression. The elastic moduli of the terminal substrate, plating, and conductor core wire, respectively, can all be determined by the terminal material type. Coating materials and wire specifications The corresponding material was retrieved from the database. Let be the area of ​​the j-th effective contact element. At each loading moment... Synchronously update contact resistance Local temperature Contact pressure and micro-displacement This generates dynamic data for the interface. ,in The contact state of the j-th unit at the current moment includes effective contact, weak contact, or gap state.

[0036] S4. Perform correlation analysis between fretting wear and electrothermal aging on the interface dynamic data to obtain degradation characteristic data; Specifically, only for the contact state Degradation analysis is performed on units with effective or weak contact. For the first... Each contact element determines the micro-slip amount based on the micro-displacement changes at adjacent loading moments: , For the first At each loading moment, For the first At each loading moment, when Greater than the preset micro-motion threshold ( ,in This represents the minimum displacement resolution for micro-displacement acquisition or simulation calculation. Used to eliminate sensor noise or numerical iteration errors. For terminal contact surface roughness, This is a roughness scaling factor, for example, 0.3, and the local contact pressure. When this occurs, it is determined that the unit has experienced fretting wear, and the wear increment of the unit is determined based on the contact pressure and slippage: ,in The wear coefficient is determined from the terminal substrate and plating materials in the material layering data. Based on local temperature. and electric heating source To determine the intensity of electrothermal aging, when and contact resistance At this time, the unit is marked as having electrothermal degradation. The system calculates the increase in contact resistance: If the same unit simultaneously satisfies , and If the temperature continues to rise, the unit is marked as a wear-electrothermal coupling degradation unit. The wear increment, contact resistance increase, temperature rise, and contact state change of each contact unit are summarized to form degradation characteristic data: .

[0037] S5. Adjust the accelerated loading based on the degradation characteristic data to obtain the stage aging loading data; Specifically, the accelerated loading process refers to the process of progressively enhancing the aging simulation loading conditions based on the current degradation state of the connection points. The system performs a basic load under rated operating current, initial ambient temperature and humidity, and initial fretting amplitude. When degradation characteristic data indicates that the contact unit has experienced increased contact resistance, localized temperature rise, fretting wear, or a transition to a weak contact state, the loading current, fretting displacement amplitude, or loading duration for the next stage is increased within the material safety boundary, thereby accelerating the aging process in a controllable manner. The accelerated loading process is divided into multiple continuous aging stages, each corresponding to a set of fixed or relatively stable loading parameters, including the stage loading current. Stage micro-displacement amplitude Stage loading duration Ambient temperature and ambient humidity ,in Numbering the aging stages .

[0038] The system counts the number of wear-electrothermal coupling degradation units within the same connection point. .like =0, then the current loading phase remains unchanged; if If the value is greater than 0, then accelerated loading adjustment begins. For the m-th aging stage, the system determines the loading adjustment direction based on the increase in contact resistance and the increase in temperature. When the condition is met... and When this occurs, it indicates that the unit has experienced accumulated heat, and the loading current for the next stage will be adjusted from the current loading current. Adjusted to: ,in For single-stage current increments, The maximum load current shall not exceed the safety withstand range of the household wiring harness. If the number of weak contact units increases, i.e. When effective contact changes to weak contact, the amplitude of the fretting displacement increases simultaneously. ,in This represents the current micro-motion loading amplitude. For the displacement amplitude increment, The displacement must not exceed the upper limit of the allowable loosening of the terminal structure. If the temperature rises... Exceeding the preset temperature rise protection threshold If the current is not increased, only the loading time of the current stage is extended to avoid thermal runaway causing the simulation results to deviate from the actual aging process. ,in The insulation layer of the conductor relative to the ambient temperature Permissible temperature rise, For terminal substrates or plating relative to ambient temperature Permissible temperature rise, The measured initial interface temperature rise after power-on stabilization. For each aging stage, the system generates stage aging load data: ,in For the stage loading current, This represents the amplitude of the stage-wise micro-displacement. For the duration of stage loading, and These are ambient temperature and ambient humidity, respectively. The number of coupled degenerate units, and These represent the increase in contact resistance and the increase in wear, respectively.

[0039] S6. Perform iterative aging assessment based on the stage aging loading data to obtain the aging behavior simulation results.

[0040] Specifically, based on phased aging loading data and by stage number Using a circular index, aging loads are executed sequentially for each stage. For the first... The system is subjected to phased aging processes, with current applied according to each phase. Stage micro-displacement amplitude Stage loading duration Ambient temperature and ambient humidity The process is repeated on the heterogeneous interface elements, and the contact resistance, local temperature, contact pressure, micro-displacement, and contact state at the end of this stage are updated to obtain the dynamic data at the end of the stage: ,in For the first The contact unit in the first Contact resistance after each aging stage This refers to the temperature at the end of the stage. For the contact pressure at the end of the stage, For the micro-displacement at the end of the stage, This is the contact state at the end of the stage.

[0041] The system accumulates the degradation amount at each stage to obtain the result. The cumulative wear and cumulative resistance increase of each contact unit: , ,in and They are respectively from the first The degradation characteristic data corresponding to each aging stage, with initial values ​​satisfying... , When the contact unit is in state When the system transitions from effective contact to weak contact or gap state, it records the corresponding stage number. Cumulative loading time: ,in As of the date The cumulative aging loading time for each aging stage.

[0042] After each loop, the system performs an aging termination check. Iteration stops if either of the following conditions is met: First, the increase in contact resistance of any contact unit satisfies... Second, the proportion of weak contact units to the total number of effective contact units exceeds 20%; third, local temperature... Fourth, the stage number reaches the maximum allowable temperature limit of the material; .in Based on the initial contact resistance The allowable growth multiple is determined, for example , A value of 0.5 indicates that the contact resistance has increased by 50% relative to the initial value, which is considered a significant degradation.

[0043] If the termination condition is not met, then the current stage's end dynamic data will be... This serves as the initial state for the next cycle, and the aging loading data for the next stage is regenerated; if the termination condition is met, the simulation results of the aging behavior are output: ,in To accumulate aging time, This represents the cumulative wear amount. This represents the cumulative increase in contact resistance. This is the final contact state. For the final temperature distribution, This is the termination stage number. The aging type is marked as either resistance-increased, weak-contact-expanded, heat-accumulation-driven, or wear-dominant, corresponding to the four conditions for determining the termination of aging mentioned above.

[0044] Preferably, heterogeneous interface modeling specifically involves: S21. Perform connection area structure analysis on the wire harness interface data to obtain interface structure partition data; Specifically, according to the wire specifications Determine the equivalent outer diameter of the conductor core wire and use the crimping height. and crimp width Construct the outer contour of the crimping area; define the inner side of the crimping area as the conductor core area, and the terminal body as the terminal substrate area; ensure that the width of the terminal mating contact surface does not exceed [a certain value]. The area is defined as the mating contact area, and the outer sheath of the conductor is defined as the insulation transition area. Based on the plating thickness... A plating area is generated on the surface of the terminal substrate to obtain interface structure partition data. ,in For the conductor core area, For the terminal substrate area, This is the coating area. For the mating contact area, This is an insulating transition region.

[0045] S22. Based on the interface structure partition data, identify the material contact relationship to obtain heterogeneous material contact data; Specifically, based on the interface structure partitioning data Determine whether there is a physical bonding, coating coverage, or gap isolation relationship between adjacent partitions. If there is a coating partition... Covering terminal substrate partition This generates a terminal substrate-plating contact relationship; if the conductor core wire is partitioned... If the conductor core is located within the crimping area and adjacent to the inner surface of the terminal substrate or plating, a conductor core-terminal crimping contact relationship is formed; if the mating contact area is partitioned... Memory is made by and The localized protrusions represent a coating-contact bump relationship; if there is an insulation transition zone... When adjacent to the terminal crimping flange, an insulating layer-terminal mechanical constraint relationship is formed. This yields the contact data for the heterogeneous materials: ,in This relates to the relationship between the terminal substrate and the plating layer. This refers to the relationship between the conductor core and the terminal. The relationship between the coating and the contact bumps. This represents the constraint relationship between the insulation layer and the terminal.

[0046] S23. Assign values ​​to the interface physical property parameters based on the heterogeneous material contact data to obtain the interface physical property parameter data; Specifically, depending on the type of terminal material Read the elastic modulus of the terminal substrate from the material parameter library. Poisson's ratio Electrical conductivity and thermal conductivity According to the coating thickness And reading the elastic modulus of the coating material Electrical conductivity and thermal conductivity According to the wire specifications Reading the conductivity of the conductor core thermal conductivity and coefficient of thermal expansion Contact data for heterogeneous materials Each contact relationship in the diagram is bound to a corresponding material parameter, and the initial contact resistance is set accordingly. Initial interface temperature rise Insertion force and pull-out force As the initial boundary parameters of the interface, the interface physical property parameter data are obtained. ,in These are the physical properties of the terminal substrate. These are the physical properties of the coating. These are the physical properties of the conductor core. These are the physical properties of the insulation transition zone.

[0047] S24. Discretize the micro-contact units based on the interface physical property parameter data to obtain the interface micro-contact unit data; Specifically, in the mating contact zone Inside, based on the effective contact width Define a discrete boundary and divide the region into multiple surface mesh elements. For the j-th surface mesh, extract its local height. And according to the height of the contact protrusion Roughness of terminal contact surface Determine the contact criterion height: ,when When, mark the grid as a valid contact element; when At this point, the mesh is marked as a gap cell. The cell area is recorded for each effective contact cell. Material parameters Initial resistance allocation values and contact status mark The interface micro-contact unit data is obtained: in Marking for effective contact or gap status.

[0048] S25. Integrate heterogeneous interface units based on the interface micro-contact unit data to obtain interface heterogeneous unit data.

[0049] Specifically, partition the interface structure data. Contact data of heterogeneous materials Interface property parameters data and interface micro-contact unit data Implement unified numbering and integration. For the same connection point... The conductor core region, terminal substrate region, plating region, contact bump units, and insulation transition region are mapped to the same geometric mesh coordinate system, while preserving the material properties, contact relationships, initial resistance, initial thermal state, and mechanical boundaries of each unit. This yields the interface heterogeneous unit data: ,in Geometric mesh data, For material layering data, Mark the contact / gap data.

[0050] Preferably, the physical field coupling loading specifically refers to: S31. Configure the loading boundary conditions for the interface heterogeneous unit data to obtain coupled loading boundary data; Specifically, The effective contact units are set as current-conducting regions, and the gap units are set as high-resistance isolation regions; based on the initial contact resistance... Assign initial resistance to effective contact units According to the interface temperature rise Set initial temperature According to the insertion force and pull-out force Set clamping load and holding force constraints to obtain coupled loading boundary data: .

[0051] S32. Apply high-frequency micro-amplitude vibration loading to the coupled loading boundary data to obtain interface vibration loading data; Specifically, based on the coupled loading boundary data A small-amplitude vibration displacement is applied to the effective contact unit and the weak contact unit along the terminal mating direction or perpendicular to the contact surface. The high-frequency vibration refers to periodic small-amplitude vibration relative to the static holding state of the wire harness connection point, and its vibration frequency is preferably 20Hz-200Hz. The vibration displacement is calculated according to the loading time. Represented as: ,in Let $\frac{ ... ,in The vibration acceleration signal at the principal vibration frequency The acceleration amplitude at point m. For the m-th aging stage, Determined based on the amplitude of fretting displacement and the results of vibration loading adjustment in the previous stage; when degradation characteristic data indicate the presence of pressure attenuation, fretting wear, or weak contact expansion, and the maximum allowable fretting displacement amplitude is not exceeded. At that time, according to: Update it. Among them... This represents the increment of micro-displacement in a single stage. The maximum permissible fretting displacement amplitude can be determined by the height of the contact protrusion. Determine, for example , To determine the vibration frequency, during the operation of a compressor, motor, fan, or pump, an accelerometer installed near the wiring harness connection point collects the vibration acceleration signal a(t), and performs spectral analysis on a(t) to extract the dominant vibration frequency with the largest amplitude as the vibration loading frequency. The fretting slip is calculated based on the displacement difference between adjacent time points: and combined with unit area Update local contact pressure with initial normal clamping force The interface vibration loading data was obtained: .

[0052] S33. Apply pulse current to the interface vibration loading data to obtain interface electrothermal loading data; Specifically, in the interface vibration loading data Based on the contact state, a pulse current boundary is applied to the effective contact unit, while no conduction current is allocated to the gap unit. The pulse current is expressed as: ,in Apply current to the current stage. This is the energized section. This is the power outage zone. For the first... Calculate the heat source for each effective contact unit: The local temperature is updated based on the electrical and thermal conductivity parameters in the material layering data. The interface electrothermal loading data was obtained: .

[0053] S34. Perform thermo-mechanical feedback correction based on the interface electrothermal loading data to obtain interface coupling correction data; Specifically, the system is based on interface electrothermal loading data. Local temperature in and electric heating source Based on material layering data The coefficient of thermal expansion is used to calculate the normal displacement correction of the contact element: ,in The corresponding material's coefficient of thermal expansion. The equivalent thickness for contact deformation. According to Corrected normal clamping force: and calculate ,in Let be the equivalent contact stiffness corresponding to the j-th contact element. At that time, the element is updated from an effective contact element to a weak contact element, and the interface coupling correction data is obtained: .

[0054] S35. Dynamically sample and integrate the interface coupling correction data to obtain dynamic interface data.

[0055] Specifically, according to the preset sampling interval Read interface coupling correction data Simultaneously, the temperature, contact resistance, contact pressure, micro-displacement, heating source, and contact state of each contact unit at the current moment are extracted. If a certain unit satisfies the following conditions at two consecutive sampling moments... If, then retain its weak contact mark; In the intermittent state, it does not participate in current distribution. The data from each sampling moment are integrated into dynamic interface data: .

[0056] Preferably, the correlation analysis between fretting wear and electrothermal aging is as follows: S41. Perform time-series alignment processing on the dynamic data of the interface to obtain synchronized data of the interface. Specifically, based on dynamic interface data , at loading time To unify the time index, for the same contact unit The temperature, contact resistance, contact pressure, micro-displacement, heating source, and contact state are time-stamped. If the sampling time of a certain parameter is... If they are inconsistent, take the distance. Linear interpolation is performed between the two most recent consecutive sample values; if the contact state... If the cell is in a gap state, it only retains temperature and status data and does not participate in wear calculations. This yields the interface synchronization data: , where superscript This indicates that timing synchronization has been completed.

[0057] S42. Based on the interface synchronization data, extract the fretting wear feature and the electrothermal aging feature to obtain the fretting wear feature data and the electrothermal aging feature data respectively. Specifically, , Let be the micro-slip amount of the j-th contact element at the k-th loading moment, when ( (for preset micro-motion threshold) and At that time, calculate the wear increment: , The wear coefficient is determined from the terminal substrate and plating material in the material layering data, and fretting wear characteristic data is formed. The fretting wear characteristic data can also be expanded by following the steps below.

[0058] The system calculates the increase in contact resistance and the increase in temperature: , And combined with electric heating source Generate electrothermal aging characteristic data .

[0059] S43. Perform coupling correlation calculations based on fretting wear characteristic data and electrothermal aging characteristic data to obtain coupled correlation characteristic data; Specifically, for the same contact unit At the same loading time The wear increment below Contact resistance increase Temperature rise and electric heating source Perform a matching operation. If the conditions are met... >0、 >0 and If the value is greater than 0, it is determined that the unit exhibits a mutually reinforcing relationship between fretting wear and electrothermal aging. The system records the coupling trigger flag: And form coupled and correlated feature data: .

[0060] S44. Degradation identification is performed based on the coupled correlation feature data to obtain degradation feature data.

[0061] Specifically, based on the coupled correlation feature data Each contact unit is identified by its degradation type. If... =1, then the unit is marked as a wear-electrothermal coupling degradation unit; if >0 and =0, then it is marked as a wear-dominated degradation unit; if =0 and >0、 If >0, it is marked as an electrothermal-dominated degradation unit; if When effective contact transitions to weak contact, it is marked as a contact relaxation degradation element. The number of coupling degradation elements within the same connection point is counted. And output degradation feature data: .

[0062] Preferably, the fretting wear feature extraction specifically involves: Based on the interface synchronization data, contact pressure attenuation processing and contact resistance jump processing are performed to obtain the first fretting wear characteristic data and the second fretting wear characteristic data. Specifically, based on interface-synchronized data For the j-th contact element, calculate the contact pressure attenuation at adjacent loading times: ,when >0 and When this occurs, it is determined that the unit has weakened contact clamping / attenuated contact pressure due to fretting, and the first fretting wear characteristic data is generated: Simultaneously calculate the contact resistance jump: ,when >0 and When the resistance jump is determined to be caused by wear debris, oxide film rupture, or a reduction in the actual contact area, a second fretting wear characteristic data is generated: .

[0063] Spatial overlap identification is performed on the first and second fretting wear feature data to obtain fretting wear spatial data; Specifically, the first fretting wear characteristic data Second fretting wear characteristic data Map back to the mesh number and spatial coordinates of the interface micro-contact element. If the same contact element... At the same loading time If both contact pressure decay and contact resistance jump conditions are met, the cell is marked as a spatially coincident wear cell; if adjacent mesh cells experience pressure decay and resistance jump at the same time, the adjacent region is marked as an extended wear region. The spatial coincidence determination can be expressed as: Thus, the spatial data of fretting wear is obtained: ,in( ) represents the spatial coordinates of the j-th contact unit.

[0064] Multidimensional degradation characterization fusion was performed on the spatial data of fretting wear to obtain characterization fusion data; Specifically, regarding the spatial data of fretting wear. The pressure attenuation, contact resistance jump, fretting slip, and contact state of the same spatially overlapping wear unit are jointly characterized. The system generates degradation characterization labels: when... >0 and When the voltage drop is greater than 0, a "voltage drop-damping" label is generated; when both conditions are met... and When the contact is weak, a "slip-weak contact" label is generated; when the same element satisfies this condition at two or more consecutive loading times... When the value is 1, a "continuous wear" label is generated. This yields the characterization fusion data: ,in This is a set of labels representing degradation.

[0065] Wear state spectrum mapping is performed based on the characterization fusion data to obtain fretting wear characteristic data.

[0066] Specifically, based on representation fusion data For the first Each contact unit is used for wear state spectrum mapping. If only one exists... If no contact pressure decay or resistance jump occurs, it is marked as the initial fretting state; if contact pressure decay occurs but contact resistance does not jump, it is marked as the clamping loosening wear state; if contact resistance jumps but pressure decay is not significant, it is marked as the conductive interface disturbance wear state; if both conditions are met... If the value is 1, it is marked as a coupled fretting wear state; if the coupled fretting wear state is maintained for multiple consecutive moments and then transitions to weak contact, it is marked as an extended wear state. The system obtains fretting wear characteristic data: ,in This serves as an identifier for the wear condition spectrum. (The aforementioned...) It can be used as the basic fretting wear feature data. The fretting wear feature data obtained by subsequent spectral mapping is the fused fretting wear feature data. The two are progressive rather than parallel and repetitive.

[0067] Preferably, the contact pressure attenuation treatment specifically includes: Capture the compressor start / stop window from the synchronized interface data to obtain the start / stop interface data; Specifically, the system synchronizes data based on the interface and simultaneously reads the operating status signal of the appliance compressor. ,in =1 indicates that the compressor is started. =0 indicates that the compressor has stopped. When a change occurs from 0 to 1 or from 1 to 0, that moment is taken as the start / stop center moment. , cut The interface synchronizes data as the start / stop window, where This is the baseline observation time before start-up and shutdown. This represents the disturbance observation duration after start-stop. From this, the start-stop interface data is obtained: .

[0068] The pressure baseline of the heterogeneous unit is constructed based on the start-stop interface data to obtain the unit pressure baseline data; Specifically, at the start / stop center time Previous stable range [ Within, for each effective contact unit Contact pressure Extract baseline pressure. If the contact state is within this range... If no effective contact, weak contact, or gap change occurs, the median pressure within that interval is taken as the unit pressure baseline. , To obtain the median, if there is a change in contact state within the interval, the sampling point before and after the change time is removed before calculating the median pressure. The pressure baseline, corresponding element number, and contact state of each contact element are recorded together to obtain the element pressure baseline data: ,in Let be the area of ​​the j-th contact unit.

[0069] Phase-related pressure attenuation is identified based on unit pressure baseline data and start / stop interface data to obtain phase pressure attenuation data. Specifically, based on the micro-displacement in the start / stop interface data Determine the start and stop vibration phases, dividing the interval between adjacent displacement peaks into one vibration cycle. For each contact element, calculate the pressure attenuation relative to the pressure baseline: ,when >0, and its occurrence time falls within the neighborhood of the micro-displacement peak or the reverse peak, thus satisfying the condition. At that time, it was determined that the pressure attenuation was related to the phase of the start-stop micro-vibration, where This represents the amplitude of the micro-displacement at the current stage. The phase neighborhood coefficient is set to 0.8. This yields the phase pressure attenuation data: ,in This is a marker for the vibration phase corresponding to pressure decay.

[0070] Thermal expansion disturbances are eliminated based on the phase pressure decay data to obtain irreversible pressure decay data. Specifically, based on phase pressure decay data Pressure attenuation in And in conjunction with the temperature change: To determine whether the pressure change is primarily caused by thermal expansion, the material's coefficient of thermal expansion is used. Equivalent contact thickness and equivalent contact stiffness Calculate the estimated pressure disturbance caused by thermal expansion: , Let be the element area of ​​the j-th contact element, if If the pressure change is determined to be a recoverable thermal expansion disturbance and eliminated; if The excess portion is then retained as irreversible pressure decay. This yields data on irreversible pressure decay: .

[0071] Pressure migration path identification is performed based on irreversible pressure decay data to obtain the first fretting wear characteristic data.

[0072] Specifically, the data on irreversible pressure decay Mapping back to the spatial coordinates of the interface micro-contact unit If adjacent cells appear sequentially at consecutive sampling times... If the pressure is greater than 0, the corresponding units are connected in chronological order to form a pressure migration path. If the irreversible pressure decay of a certain unit persists and the pressure of its adjacent units increases, it is determined that there is contact pressure transfer caused by fretting wear in that area. The path start point, end point, units traversed, irreversible pressure decay amount, and corresponding contact state are recorded as the first fretting wear characteristic data. ,in This serves as a pressure migration path identifier, used to characterize the process of contact pressure transferring from the wear area to the adjacent area under start-stop micro-vibration. Pressure migration path identification extends the judgment of single-point pressure attenuation to a spatial migration process characterization, and can serve as a spatial extension layer of the first fretting wear characteristic data.

[0073] Preferably, the contact resistance jump treatment specifically includes: Contact resistance sequence is extracted from the interface synchronization data to obtain interface resistance time series data; Specifically, based on interface synchronization data, by contact unit number and loading time For indexing, only the contact state is extracted. This represents the unit resistance value for effective or weak contact. For gap units, only the state is recorded, and sudden jumps are not included in the judgment. The contact resistance of the same contact unit at consecutive sampling times is arranged in chronological order to form interface resistance time-series data: ,in Assign the corresponding time to the first The current in each contact unit is used to determine whether a change in resistance occurs during the conduction state.

[0074] Based on the interface resistance timing data, a resistance baseline is constructed to obtain the contact resistance baseline data; Specifically, within each loading stage, the time interval during which the current conduction is stable and the contact state remains unchanged is selected as the resistance baseline interval. For the first... A contact unit, if within the baseline interval Always effective contact, and If the value is greater than 0, then the median value of the contact resistance within that interval is taken as the resistance baseline. If a weak contact jump exists within this interval, the sampling point before and after the jump time is removed before calculating the median. This yields the baseline contact resistance data: ,in For the initial contact resistance The initial resistance obtained by unitization.

[0075] Contact conduction transient instability is captured based on contact resistance baseline data and interface resistance timing data to obtain resistance jump data; Specifically, the current contact resistance With resistance baseline and the resistance at the previous sampling time Compare and calculate the resistance jump: ,when >0、 ,and When the value is greater than 0, the unit is determined to have transient instability due to contact conduction; if the conditions are met simultaneously... If so, the jump is marked as related to a decrease in contact pressure. This yields the resistance jump data: .

[0076] Based on the resistance jump data, the vibration phase and current pulse correlation are verified to obtain the resistance jump correlation data. Specifically, based on resistance jump data micro-displacement and pulse current state The moment the resistance jump occurs is within the current conduction / current-carrying region. And the micro displacement satisfies At that time, it was determined that the resistor jump was related to the peak phase of the vibration and the conduction current pulse, wherein... The phase neighborhood coefficient is set to 0.8. This represents the amplitude of the micro-displacement at the current stage. If the jump occurs during the power outage interval or in the vicinity of the non-peak displacement, it is marked as an atypical jump. This yields the resistance jump correlation data: ,in This is a marker for vibration phase correlation.

[0077] Based on the resistance jump correlation data, the jump feature is identified to obtain the second fretting wear feature data.

[0078] Specifically, based on resistance jump correlation data For the first Each contact unit is identified by its jump type. If >0、 ,and If the resistance jump is located in the vicinity of the vibration peak, it is marked as a vibration-conducting resistance jump; if the resistance jump is accompanied by a contact state... If the contact changes from effective to weak, it is marked as a weak contact transition type resistance jump; if the same unit repeatedly experiences jumps within multiple consecutive start-stop windows, it is marked as a repetitive instability type resistance jump. Generate the second fretting wear characteristic data: ,in It is a characteristic identifier for resistance jumps, used to characterize fluctuations in conduction area, contact film rupture, or weak contact expansion processes caused by fretting wear.

[0079] Preferably, the accelerated loading adjustment specifically includes: S51. Degradation rate identification is performed on the degradation feature data to obtain degradation rate assessment data; Specifically, based on degradation feature data, the degradation rate is identified by the change in degradation increment between two adjacent loading times. For the first... For each contact element, calculate the wear rate and resistance increase rate: , ,like =1, then this unit is included in the coupling degradation rate statistics; if When the contact changes from effective to weak, the moment of state transition is recorded. This yields degradation rate assessment data: It is used to determine whether the current aging process requires an increase in loading intensity.

[0080] S52. Determine the loading safety boundary based on the degradation rate assessment data to obtain the loading boundary constraint data; Specifically, data is assessed based on the rate of degradation. Temperature rise in Resistance growth rate and the number of coupling degenerate units Determine if the current load is close to the safety boundary. The preset temperature rise protection threshold meets the following requirements: ,when When the contact ratio is low, it is forbidden to increase the loading current; when the contact ratio is low, it is forbidden to increase the loading current. ( When the value is 0.2, the accelerated loading stops; when neither the limit nor the constraint is reached, the next stage of loading adjustment is allowed. This yields the loading boundary constraint data: ,in The maximum allowable load current is set to 1.3 times the rated current. The maximum permissible fretting displacement amplitude is set to 0.8 times the height of the contact protrusion. This is a current adjustment permission flag; a value of 1 indicates that current can be increased, and a value of 0 indicates that current cannot be increased. This is a vibration amplitude adjustment permission flag. A value of 1 indicates that the vibration amplitude can be increased, while a value of 0 indicates that the vibration amplitude cannot be increased.

[0081] S53. Adjust the vibration loading parameters according to the loading boundary constraint data to obtain the vibration adjustment parameter data; Specifically, based on the loaded boundary constraint data and the amplitude of the micro-displacement at the current stage .like Furthermore, the degradation rate assessment data contains... , If the contact state changes from effective contact to weak contact, then the amplitude of the micro-motion displacement in the next stage will be increased: If the proportion of weak contact is already close Then keep The frequency remains unchanged to prevent the terminal structure from entering a state of non-real loosening. Maintain the vibration frequency consistent with the compressor's start-up and shutdown or equipment operating conditions, and do not arbitrarily increase it. This yields the vibration adjustment parameter data: .

[0082] S54. Adjust the electrothermal loading parameters according to the loading boundary constraint data and vibration adjustment parameter data to obtain the electrothermal adjustment parameter data; Specifically, read the loaded boundary constraint data. Vibration adjustment parameter data and the current applied current at the current stage .like And exist , or Then the loading current for the next stage will be adjusted as follows: ,like Then let and only extend the loading time. For pulsed current loading, the on / off period remains constant; only the current amplitude within the conduction interval is adjusted to avoid altering the electrothermal loading mechanism. This yields the following electrothermal regulation parameter data: .

[0083] S55. Based on the vibration adjustment parameter data and the electrothermal adjustment parameter data, a stage loading scheme is generated to obtain stage aging loading data.

[0084] Specifically, the vibration adjustment parameter data In , With electric heating regulation parameter data In , , Combine them, and take into account the ambient temperature. Ambient humidity and the duration of stage loading Generate the next stage loading plan. If the current degradation rate is lower than the preset observation requirement, maintain... and Unchanged and extended If the degradation rate increases but does not reach the safety boundary, the updated current and vibration amplitude are used. The system obtains stage aging load data: , The number of coupled degenerate units at the k-th loading time. Let be the increase in contact resistance of the j-th contact element at the k-th loading moment. This represents the wear increment of the j-th contact element at the k-th loading moment.

[0085] Preferably, the cyclic iterative aging assessment specifically includes: S61. Perform cyclic loading based on the stage aging loading data to obtain stage cycle data; Specifically, based on the stage aging loading data, and using the stage number m as a cyclic index, corresponding pulse current, fretting displacement, ambient temperature, and ambient humidity loading are applied to the interface heterogeneous unit. Within each stage, according to the sampling interval... Generate loading time And record the contact resistance at each time point. ,temperature Contact pressure micro-displacement and contact state The stage cycle data is obtained: ,in Used to indicate the first The UI response after the stage loads.

[0086] S62. Update the degradation trajectory of the stage loop data to obtain the harness degradation trajectory data; Specifically, based on the stage cycle data Extract the contact resistance increase, wear increment, temperature peak, and contact state change of each contact unit at the end of this stage, and superimpose them with the cumulative results from the previous stage. For the j-th contact unit, the cumulative wear and cumulative resistance increase are respectively: , The initial value is , Simultaneously record the highest temperature during the period. and contact state This generates harness degradation trajectory data: It is used to characterize the degradation and evolution process of connection points as cyclic loading progresses.

[0087] S63. Based on the wiring harness degradation trajectory data, identify the early signs of stage failure and obtain the early signs of failure data; Specifically, reading the harness degradation trajectory data It identifies four types of failure precursors: continuous increase in contact resistance, expansion of weak contacts, continuous increase in temperature, and continuous decrease in pressure. When two or more consecutive aging stages meet the following criteria... When, it is marked as a precursor to electrothermal accumulation; when When the contact changes from effective contact to weak contact or a gap state, it is marked as a precursor to contact relaxation; when and At this time, it is marked as a precursor to wear propagation. From this, we obtain the failure precursor data: ,in This is a marker for the precursor type.

[0088] S64. Based on the failure precursor data, perform a loop termination iteration determination to obtain aging iteration determination data; Specifically, based on failure precursor data Determine whether to terminate the loop. If any contact element satisfies... If the resistance increases to the point that the failure condition has been met, then the number of weak contact units is considered to be [missing information]. Number of initial effective contact units The ratio satisfies: If the weak contact propagation reaches the failure condition, then it is determined that the weak contact propagation has reached the failure condition. Take 0.20; if The iteration terminates if the material's allowable temperature limit is exceeded, or if the stage number m reaches the maximum stage number M. Aging iteration judgment data is obtained: ,in As a termination marker, The reason for termination.

[0089] S65. Based on the aging iteration judgment data and the wiring harness degradation trajectory data, the failure mode assessment is performed to obtain the aging behavior simulation results.

[0090] Specifically, when aging iteration determines data middle When =1, the system reads the harness degradation trajectory data up to the termination stage. And determine the failure mode based on the primary triggering cause. If the termination cause is... If the failure is due to increased contact resistance, it is marked as a contact resistance increase type failure; if the termination reason is... If the failure is due to excessive temperature, it is marked as a weak contact propagation type failure; if the cause of termination is excessive temperature, it is marked as a heat accumulation type failure; if the cumulative wear amount is... If the pressure continues to increase while it continues to decrease, it is classified as a fretting wear-dominated failure. The system outputs simulation results of the aging behavior: ,in, Used to represent the cumulative aging loading time. Let r be the loading duration of the r-th aging stage. This is the final failure mode.

[0091] Preferably, this application also provides a home wiring harness aging behavior simulation system for performing the home wiring harness aging behavior simulation method described above, the home wiring harness aging behavior simulation system comprising: The interface parameter acquisition module is used to acquire the initial interface parameters of the home appliance wiring harness connection points and obtain the wiring harness interface data. The heterogeneous interface modeling module is used to perform heterogeneous interface modeling based on the wire harness interface data to obtain interface heterogeneous unit data. The physical field coupling loading module is used to perform physical field coupling loading based on the interface heterogeneous unit data to obtain interface dynamic data. The degradation feature extraction module is used to perform correlation analysis between micro-motion wear and electrothermal aging on interface dynamic data to obtain degradation feature data; The staged aging loading module is used to adjust the accelerated loading based on degradation characteristic data to obtain staged aging loading data. The aging behavior simulation module is used to perform iterative aging assessments based on stage aging loading data to obtain aging behavior simulation results.

[0092] Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended application documents rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of the equivalents of the application documents be incorporated into the invention.

[0093] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A method of simulating the aging behavior of a household appliance wire harness, characterized in that, Includes the following steps: Obtain the initial interface parameters of the home appliance wiring harness connection points to obtain the wiring harness interface data; Heterogeneous interface modeling is performed based on the wire harness interface data to obtain interface heterogeneous unit data; Physical field coupling loading is performed based on the interface heterogeneous unit data to obtain the interface dynamic data; Correlation analysis between fretting wear and electrothermal aging was performed on the dynamic data of the interface to obtain degradation characteristic data; Accelerated loading is adjusted based on degradation characteristic data to obtain staged aging loading data; Based on the stage aging loading data, iterative aging assessments are performed to obtain aging behavior simulation results.

2. The method of claim 1, wherein, Heterogeneous interface modeling specifically involves: The connection region structure of the wire harness interface data is analyzed to obtain interface structure partition data; based on the interface structure partition data, material contact relationships are identified to obtain heterogeneous material contact data. Interfacial property parameters are assigned based on the contact data of heterogeneous materials to obtain interfacial property parameter data; Micro-contact units are discretized based on interface physical property parameter data to obtain interface micro-contact unit data; Heterogeneous interface units are integrated based on the interface micro-contact unit data to obtain interface heterogeneous unit data.

3. The method according to claim 1, characterized in that, The physical field coupling loading is specifically as follows: The interface heterogeneous unit data is loaded with boundary conditions to obtain coupled loading boundary data; the coupled loading boundary data is subjected to high-frequency micro-amplitude vibration loading to obtain interface vibration loading data. Pulse current was applied to the interface vibration loading data to obtain interface electrothermal loading data; The interface coupling correction data is obtained by performing thermo-mechanical feedback correction based on the interface electrothermal loading data. Dynamic sampling and integration are performed based on the interface coupling correction data to obtain dynamic interface data.

4. The method according to claim 1, characterized in that, The specific correlation analysis between fretting wear and electrothermal aging is as follows: The dynamic interface data is time-aligned to obtain synchronized interface data; based on the synchronized interface data, fretting wear features and electrothermal aging features are extracted to obtain fretting wear feature data and electrothermal aging feature data, respectively; based on the fretting wear feature data and electrothermal aging feature data, coupling correlation calculation is performed to obtain coupled correlation feature data. Degradation identification is performed based on the coupled correlation feature data to obtain degradation feature data.

5. The method according to claim 4, characterized in that, The specific steps for extracting fretting wear features are as follows: Based on the interface synchronization data, contact pressure attenuation processing and contact resistance jump processing are performed to obtain first fretting wear characteristic data and second fretting wear characteristic data; spatial overlap identification is performed on the first fretting wear characteristic data and second fretting wear characteristic data to obtain fretting wear spatial data; multidimensional degradation characterization fusion is performed on the fretting wear spatial data to obtain characterization fusion data; wear state spectrum mapping is performed based on the characterization fusion data to obtain fretting wear characteristic data.

6. The method according to claim 5, characterized in that, The contact pressure attenuation treatment is specifically as follows: The compressor start / stop window is captured from the interface synchronization data to obtain start / stop interface data; the pressure baseline of the heterogeneous unit is constructed based on the start / stop interface data to obtain unit pressure baseline data; the phase-related pressure decay is identified based on the unit pressure baseline data and the start / stop interface data to obtain phase pressure decay data; thermal expansion disturbance is eliminated based on the phase pressure decay data to obtain irreversible pressure decay data. Pressure migration path identification is performed based on irreversible pressure decay data to obtain the first fretting wear characteristic data.

7. The method according to claim 5, characterized in that, The specific steps for handling sudden jumps in contact resistance are as follows: Contact resistance sequence is extracted from the interface synchronization data to obtain interface resistance time series data; a resistance baseline is constructed based on the interface resistance time series data to obtain contact resistance baseline data. Contact conduction transient instability is captured based on contact resistance baseline data and interface resistance timing data to obtain resistance jump data; Based on the resistance jump data, the vibration phase and current pulse are correlated and verified to obtain the resistance jump correlation data; based on the resistance jump correlation data, the jump feature is identified to obtain the second fretting wear feature data.

8. The method according to claim 1, characterized in that, The specific adjustments for accelerating loading are as follows: The degradation rate is identified from the degradation characteristic data to obtain degradation rate assessment data; the loading safety boundary is determined based on the degradation rate assessment data to obtain loading boundary constraint data; the vibration loading parameters are adjusted based on the loading boundary constraint data to obtain vibration adjustment parameter data; the electrothermal loading parameters are adjusted based on the loading boundary constraint data and the vibration adjustment parameter data to obtain electrothermal adjustment parameter data; and a staged loading scheme is generated based on the vibration adjustment parameter data and the electrothermal adjustment parameter data to obtain staged aging loading data.

9. The method according to claim 1, characterized in that, The cyclic iterative aging assessment is specifically as follows: The stage aging loading data is used to perform cyclic loading to obtain stage cyclic data; the stage cyclic data is updated with degradation trajectory to obtain harness degradation trajectory data; the harness degradation trajectory data is used to identify stage failure precursors to obtain failure precursor data. Based on the failure precursor data, the cyclic termination iteration is determined to obtain aging iteration determination data; Failure mode assessment was performed based on aging iteration judgment data and harness degradation trajectory data to obtain aging behavior simulation results.

10. A system for simulating the aging behavior of household electrical wiring harnesses, characterized in that, For performing the household wiring harness aging behavior simulation method as described in claim 1, the household wiring harness aging behavior simulation system comprises: The interface parameter acquisition module is used to acquire the initial interface parameters of the home appliance wiring harness connection points and obtain the wiring harness interface data. The heterogeneous interface modeling module is used to perform heterogeneous interface modeling based on the wire harness interface data to obtain interface heterogeneous unit data. The physical field coupling loading module is used to perform physical field coupling loading based on the interface heterogeneous unit data to obtain interface dynamic data. The degradation feature extraction module is used to perform correlation analysis between micro-motion wear and electrothermal aging on interface dynamic data to obtain degradation feature data; The staged aging loading module is used to adjust the accelerated loading based on degradation characteristic data to obtain staged aging loading data. The aging behavior simulation module is used to perform iterative aging assessments based on stage aging loading data to obtain aging behavior simulation results.

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