A method for identifying and equivalent modeling of resistance components of a crimped electrical contact structure

Abstract

The application discloses a crimping electrical contact structure resistance component identification and equivalent modeling method, and belongs to the technical field of electrical contact modeling and wire harness crimping simulation. In view of the defects that existing modeling is difficult to distinguish between entity resistance and interface contact resistance, cannot quantify the contribution of various resistance losses, and cannot accurately locate the conduction short board, the application collects surface node coordinates of crimping conductive parts to identify contact relationship, splits independent subassemblies in the circumferential direction of the parts, divides contact and non-contact areas alternately distributed along the axial direction, calculates three types of resistances of interface contact, contact area body and non-contact area body, sequentially constructs local and complete resistance networks, solves the resistance networks by means of a node current method, and extracts multiple equivalent resistances according to physical categories. The application is suitable for simulation, process optimization and reliability analysis of crimping structures such as new energy high-voltage wire harnesses and energy storage terminals.

Description

Technical Field

[0001] This invention relates to the field of electrical contact modeling and wire harness crimping simulation, specifically to a method for identifying the resistance components and equivalent modeling of crimped electrical contact structures. Background Technology

[0002] Crimped electrical contact structures are widely used in high-voltage wiring harnesses for new energy vehicles, energy storage connection components, power connectors, industrial conductive terminals, and aerospace electrical interconnection systems. These structures typically use mechanical crimping to plastically deform multiple conductors and terminals, creating electrical continuity. Their conductivity directly affects the power loss, temperature rise, current carrying capacity, and long-term reliability of the connection structure. Unlike integrally machined or welded connections, crimped electrical contact structures involve both current conduction within the conductive components and cross-sectional current transfer between the interfaces of different conductive components. Therefore, their total resistance is usually composed of multiple resistive components. For crimped electrical contact structures, resistance does not only originate from the interface contact between conductors and terminals or between conductors. Between any two conductive components in contact, there may be alternating contact and non-contact areas along the axial direction. Within the contact area, current is transferred across the interface contact spots between the two components and also continues to flow within the conductive components; therefore, both interface contact resistance and contact area volume resistance exist within the contact area. In the non-contact area, no cross-boundary transmission occurs between conductive parts, but current can still be conducted along their respective physical paths, corresponding to the volume resistance of the non-contact area. If the press-fit structure is described only by the contact interface resistance or the overall equivalent resistance, it will be difficult to determine the spatial allocation and contribution ratio of different resistance components.

[0003] In the prior art, the invention patent with authorization announcement number CN120180747B and titled "A Modeling and Calculation Method for the Resistance of Wiring Harness Terminals in New Energy Vehicles" discloses a method for modeling and calculating the resistance of wiring harness terminals in new energy vehicles. This method extracts the spatial coordinates of the surface nodes of N crimped wires and terminals, determines the contact domain range of different parts, refines the nodes within the contact domain through interpolation, calculates the contact contour point set within the contact domain along the axial direction of the wires, and calculates the actual contact length, contact width, and contact resistance between the contacting parts based on the contact contour point set. Then, it establishes a wiring harness terminal resistance network model based on the spatial distribution relationship of the wires and terminals. This technology can establish a contact resistance network based on the actual geometry after crimping, which is of great significance for improving the modeling accuracy of wiring harness terminal resistance.

[0004] However, the main technical focus of CN120180747B revolves around contact domain identification, contact contour extraction, contact length and width calculation, and contact resistance network establishment. Its emphasis is on calculating the contact resistance at the contact interface and constructing the wire harness terminal resistance network model. For the solid conductive paths within the press-fit structure, this scheme does not further segment the volume resistance spatially according to the contact and non-contact areas, nor does it define the solid conductive path resistance on both sides of the central contact node within the same contact area as the contact area volume resistance and model it collaboratively with the interface contact resistance. Therefore, when analyzing the sources of total resistance, it remains difficult to distinguish the specific contributions of the interface contact resistance, the contact area volume resistance, and the non-contact area volume resistance.

[0005] Furthermore, in structures where multiple wires are crimped together within a terminal, a single wire may simultaneously contact multiple adjacent wires and the terminal. If a contact resistance network is established solely based on the contact domains between components, the boundaries of the computational domains corresponding to different contact objects for the same wire may be unclear, thus affecting the attribution of volume resistance and contact resistance components under different contact object conditions. Especially in engineering analysis, when the total resistance abnormally increases, it is necessary to determine whether the dominant factor originates from the physical resistance of the wire harness, the physical resistance of the terminal, the contact resistance between wire harnesses, or the contact resistance between the wire harness and the terminal. Existing methods typically cannot directly provide classification equivalent resistance parameters with clear physical meaning.

[0006] Therefore, it is still necessary to propose a new method for identifying and equivalently modeling the resistance components of crimped electrical contact structures. This method should not only be able to establish a resistance network, but also to clearly define the spatial assignment and physical category of different resistance components within the network. This would allow for the extraction of various equivalent resistance components, providing a more direct basis for crimped structure design, process parameter optimization, identification of dominant resistance components, and conduction reliability assessment. Summary of the Invention

[0007] To address the problems of unclear attribution of different resistance components, insufficient expression of the coupling relationship between volume resistance and contact resistance, and difficulty in extracting equivalent resistance parameters after solving the complete network in existing resistance modeling of press-fit electrical contact structures, this invention provides a method for identifying and equivalently modeling the resistance components of press-fit electrical contact structures, including:

[0008] S1. Obtain the surface node spatial coordinates of each conductive part in the crimped electrical contact structure after crimping is completed. The conductive part includes at least one wire and at least one terminal. Based on the surface node spatial coordinates, determine the distance and contact state between any two conductive parts, determine the contact relationship between each conductive part, and output a list of contact part pairs.

[0009] S2. Guided by the contact objects in the contact part pair list, perform circumferential partitioning on each conductive part: divide the same conductive part into one or more sub-components facing different contact objects, each sub-component corresponding to a wire-to-wire contact relationship or a wire-to-terminal contact relationship, and output the geometric boundary data of each sub-component;

[0010] S3. Based on the geometric boundary data of the sub-components, slice any pair of adjacent sub-components with a contact relationship along the axial direction of the press-fit structure, extract the boundary points of the sub-components at each slice to reconstruct the contact profile between adjacent sub-components; divide the contact profile according to the axial continuity criterion to obtain one or more contact areas arranged alternately along the axial direction and non-contact areas located between adjacent contact areas, and output the axial boundary and topological features of each area.

[0011] S4. Based on the topological characteristics of each region, extract a set of parameters including the axial boundary of the region, the center node of the region, the center contact node of the contact region, the effective conductive cross-sectional area of ​​each axial slice position, and the equivalent contact width between adjacent slices, and output the geometric and material parameters for resistance calculation.

[0012] S5. Based on the geometric and material parameters, identify and calculate three types of resistive elements: the resistance corresponding to the current transmitted between adjacent sub-components through the contact interface is identified as the interface contact resistance; the physical conductive path resistance located in the contact area and on both sides of the central contact node in the same sub-component is identified as the contact area volume resistance; and the physical conductive path resistance located in the non-contact area in the same sub-component is identified as the non-contact area volume resistance.

[0013] S6. Using the center contact node of the contact area, the center node of the non-contact area, and the axial boundary node of the area as network nodes, the body resistance of the contact area and the body resistance of the non-contact area are connected in series along the axial direction of the conductive parts according to the current conduction path, and the interface contact resistance is connected in parallel between the center contact nodes of adjacent sub-components to form a local resistance network of adjacent sub-component pairs, and the topological connection relationship of the local network is output.

[0014] S7. According to the spatial position relationship and shared node relationship of each local resistor network in the press-fit electrical contact structure, multiple local resistor networks are spliced ​​together, and redundant nodes are eliminated to obtain a complete resistor network. The node admittance matrix of the complete network is output.

[0015] S8. Apply current input, output and reference potential boundary conditions to the complete resistor network, and solve for the branch current and power of each resistor element based on the nodal current method; merge according to the physical category to which the resistor element belongs, and extract at least one equivalent resistance component from the following: harness body resistance, terminal body resistance, harness-to-harness contact resistance, and harness-to-terminal contact resistance.

[0016] Furthermore, the determination of the contact relationship between each conductive component in S1 is specifically as follows: for any two conductive components, set a node spacing threshold, a pressure threshold, read the binary contact identifier, and construct a signed distance field; if the region satisfies any comparison condition, the two conductive components are determined to be a contact component pair.

[0017] Furthermore, the method of dividing each conductive component into circumferential sections as described in S2 is as follows: when the conductors are in contact with each other, the sub-assemblies are divided by the angle bisector of the centroid connecting line; when the conductors are in contact with the terminal and other conductors at the same time, the terminal contact sector is first cut off as the terminal contact sub-assembly, and the remaining area is divided into conductor contact sub-assemblies.

[0018] Furthermore, the axial continuity criterion in S3 is as follows: the reconstructed contact contour points are sorted along the axial coordinates, and an axial spacing threshold Δz is configured. If the axial spacing between adjacent contact contour points is less than Δz, they are classified as the same contact area; otherwise, it is determined that there is a non-contact area between them.

[0019] Furthermore, in S4, the method for extracting the effective conductive cross-sectional area is as follows: the boundary points of the sub-components at the slice are enclosed into an irregular polygon, the triangles are subdivided, and the areas are accumulated to obtain the effective conductive cross-sectional area of ​​the slice.

[0020] Furthermore, in S5, the volume resistance of the contact area and the volume resistance of the non-contact area are determined according to the conductive path length and the effective conductive cross-sectional area. For the volume resistance within any axial interval [z1, z2], the continuous form is:

[0021]

[0022] The discrete form is:

[0023]

[0024] Where ρ is the resistivity of the material of the corresponding conductive component, A(z) is the effective conductive cross-sectional area at the axial position z, and Δz m Let A be the length of the m-th discrete axis segment. m The effective conductive cross-sectional area corresponding to the m-th discrete axis segment;

[0025] The interface contact resistance is determined based on the equivalent contact area. For the k-th axial slice unit, let the equivalent contact area A. k =w k ·Δl k Equivalent circular contact radius Then the interface contact resistance corresponding to the k-th axial slice unit is:

[0026]

[0027] Where, ρ p ρ q The resistivity of the materials of two adjacent sub-components, w k Let Δl be the equivalent contact width of the k-th axial slice element. k is the axial length of the k-th axial slice unit; when the same contact area includes multiple axial slice units, the interface contact resistances corresponding to the multiple axial slice units are combined in parallel to form the interface contact resistance of the contact area.

[0028] Furthermore, in S6, the method for constructing the local resistor network is as follows: the axial midpoint of the contact area is taken as the central contact node, and the contact area volume resistors are respectively connected to both sides of the central contact node; the interface contact resistors are connected between the central contact nodes of adjacent sub-components; the non-contact area volume resistors are connected to both ends of the non-contact area, and the contact areas before and after are connected along the axial direction.

[0029] Furthermore, in S8, the specific method for solving the complete resistive network and extracting its equivalent resistance components is as follows: using the nodal voltage equations... Solve the complete resistive network; calculate the branch current and power based on the voltage difference between the nodes across the resistors and the resistance values ​​of the resistors; convert the total power of all resistors of the same physical category into equivalent resistance:

[0030]

[0031] Where g represents the wire harness body resistance, terminal body resistance, wire harness-to-wire harness contact resistance, or wire harness-to-terminal contact resistance.

[0032] In the formula, G is the node admittance matrix, U is the node voltage vector, I is the node injected current vector, and I0 is the total input current. The equivalent resistance corresponding to category g. The power loss of the e-th resistive element is... This indicates that all the resistor elements belonging to category g are traversed.

[0033] A system for identifying and equivalent modeling the resistive components of a press-fit electrical contact structure is also provided, for performing the method described in any of the preceding claims, including:

[0034] A geometric acquisition contact pairing unit is used to acquire the surface node spatial coordinates of each conductive part in the crimped electrical contact structure after crimping is completed. The conductive part includes at least one wire and at least one terminal. Based on the surface node spatial coordinates, the distance and contact state between any two conductive parts are determined, the contact relationship between each conductive part is determined, and a list of contact part pairs is output.

[0035] The circumferential partitioning unit is used to partition each conductive part circumferentially based on the contact objects in the contact part pair list: the same conductive part is divided into one or more sub-components facing different contact objects, each sub-component corresponds to a wire-to-wire contact relationship or a wire-to-terminal contact relationship, and outputs the geometric boundary data of each sub-component.

[0036] The axial slicing partitioning unit is used to slice any pair of adjacent sub-components with a contact relationship along the axial direction of the press-fit structure based on the geometric boundary data of the sub-components, extract the boundary points of the sub-components at each slice to reconstruct the contact contour between the adjacent sub-components; divide the contact contour according to the axial continuity criterion to obtain one or more contact regions arranged alternately along the axial direction and non-contact regions located between adjacent contact regions, and output the axial boundary and topological features of each region.

[0037] The geometric parameter extraction unit is used to extract a set of parameters based on the topological characteristics of each region, including the axial boundary of the region, the center node of the region, the center contact node of the contact region, the effective conductive cross-sectional area of ​​each axial slice position, and the equivalent contact width between adjacent slices, and outputs geometric and material parameters for resistance calculation.

[0038] A multi-resistance calculation unit is used to identify and calculate three types of resistive elements based on the geometric and material parameters: the resistance corresponding to the current transmitted between adjacent sub-components through the contact interface is identified as the interface contact resistance; the physical conductive path resistance located in the contact area and on both sides of the central contact node in the same sub-component is identified as the contact area volume resistance; and the physical conductive path resistance located in the non-contact area in the same sub-component is identified as the non-contact area volume resistance.

[0039] The local resistance network construction unit is used to connect the contact area body resistance and the non-contact area body resistance in series along the axial direction of the conductive parts according to the current conduction path, using the center contact node of the contact area, the area center node of the non-contact area and the area axial boundary node as network nodes, and to connect the interface contact resistance in parallel between the center contact nodes of adjacent sub-components to form a local resistance network of adjacent sub-component pairs, and output the topological connection relationship of the local network.

[0040] The complete resistance network splicing unit is used to splice multiple local resistance networks according to the spatial position relationship and shared node relationship of each local resistance network in the press-fit electrical contact structure, eliminate redundant nodes to obtain a complete resistance network, and output the node admittance matrix of the complete network.

[0041] The network solution equivalent resistance extraction unit is used to apply current input, output and reference potential boundary conditions to the complete resistor network, and solve for the branch current and power of each resistor element based on the nodal current method; it is then grouped according to the physical category to which the resistor element belongs, and at least one equivalent resistance component is extracted from the following: harness body resistance, terminal body resistance, harness-to-harness contact resistance, and harness-to-terminal contact resistance.

[0042] The beneficial effects of the present invention are: (1) The present invention not only calculates the contact resistance of the contact interface, but also clearly identifies the volume resistance of the contact area and the volume resistance of the non-contact area, which can more completely characterize the coupling relationship between the solid conductive path and the interface conductive path in the press-fit electrical contact structure.

[0043] (2) By using contact object-oriented circumferential partitioning, the present invention separates the areas of the same conductive part facing different contact objects into different sub-components, which can reduce the risk of aliasing of resistance calculation domains and unclear resistance attribution in multi-contact object scenarios.

[0044] (3) The present invention obtains an alternating sequence of contact and non-contact areas by segmenting the axial continuity, which can reflect the characteristics of the non-continuous distribution of contact state along the axial direction in the actual morphology after pressing, and avoids simplifying local contact into overall continuous contact.

[0045] (4) The present invention introduces a central contact node in the contact area, unifying the interface contact resistance and the contact area volume resistance on both sides of the central contact node into the same local network topology, which can express the real conduction relationship of current in the physical path and the cross-boundary contact path.

[0046] (5) After solving the complete resistance network, the present invention extracts the equivalent resistance parameters according to the physical category. This not only obtains the total resistance, but also determines the contribution ratio of different resistance components to the total resistance, which is convenient for locating the dominant resistance source.

[0047] (6) The present invention is applicable to complex crimping structures composed of multiple wires and terminals, and is also applicable to other crimping electrical contact structures with multiple conductive parts, multiple contact interfaces and distributed conductive paths. Attached Figure Description

[0048] Figure 1 This is a flowchart illustrating the method for identifying and equivalently modeling the resistive components of the press-fit electrical contact structure according to the present invention.

[0049] Figure 2 This is a schematic diagram illustrating the circumferential partitioning of the contact object based on the angle bisector of the centroid connection line when two conductors are in contact.

[0050] Figure 3 This is a schematic diagram of a sub-assembly for determining the effective contact of a terminal when a wire contacts a terminal.

[0051] Figure 4 A schematic diagram showing the division of contact and non-contact areas along the axial direction for adjacent sub-components.

[0052] Figure 5 This is a schematic diagram of the local network of the interface contact resistance, the volume resistance of the left contact area, and the volume resistance of the right contact area within the contact region.

[0053] Figure 6 This is a schematic diagram of a local network connecting the volume resistance of the non-contact region with the volume resistance of the adjacent contact region.

[0054] Figure 7 This is a schematic diagram of a complete resistor network formed by splicing together multiple local resistor networks.

[0055] Figure 8 This is a schematic diagram of extracting the equivalent resistance components based on a complete resistance network. Detailed Implementation

[0056] The technical solution of the present invention will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. In the following embodiments, process equipment or devices not specifically specified are all conventional equipment or devices in the art. Unless specifically specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0057] Example 1 illustrates the complete process of resistance component identification and equivalent modeling using a multi-wire terminal crimping structure as an example:

[0058] To clearly illustrate the complete implementation logic of this invention, this embodiment selects a conductive connection structure formed by crimping multiple wires to a single terminal as the analysis object, wherein each wire is labeled as W1, W2, ..., W... N The terminal is marked as T. After the wires and terminals undergo plastic deformation through crimping, multiple discrete local contact interfaces will be formed between the wires and between the wires and the inner wall of the terminal. Existing modeling methods have difficulty distinguishing the respective loss contributions of the solid body resistance and the interface contact resistance. This embodiment combines the complete process shown in Figure 1 with the attached figure. Figure 2 To be continued Figure 8 Visualized geometric partitioning, region segmentation, resistor topology, full network stitching, and equivalent classification logic are all implemented throughout the entire process of this invention, as detailed below:

[0059] S1. Acquisition of surface node spatial coordinates and contact recognition:

[0060] Obtain the spatial coordinates of the surface nodes of each conductive component after crimping. For the p-th conductive component, its set of surface node spatial coordinates can be represented as:

[0061]

[0062] Where, n p Let x be the number of surface nodes of the p-th conductive component. p,i y p,i z p,i These are the spatial coordinates of the i-th surface node in a unified coordinate system. Preferably, the axial direction of the press-fit structure is defined as the z-direction, and the plane containing the cross-section is defined as the xoy plane.

[0063] For any two conductive parts p and q, determine whether they are in contact. This determination can be made using node distance thresholds, finite element contact states, contact pressure results, or signed distance fields. If surface nodes satisfy a preset contact criterion, then p and q are determined to be a pair of contacting parts. The contact relationship obtained in this step is used for subsequent circumferential partitioning and local network construction.

[0064] S2. Contact object-oriented circumferential partitioning:

[0065] The partitioning rules for this step are attached. Figure 2 Appendix Figure 3 Appendix Figure 2 For scenarios involving contact between wires, this demonstrates the geometric logic of dividing the system into independent sub-components based on the angle bisector of the centroid connection line; (attached) Figure 3 This demonstrates how to extract and split terminal-specific sub-components in a scenario where a wire simultaneously contacts a terminal and other wires.

[0066] For any target conductor W p If it is in contact with multiple adjacent conductors at the same time, the centroid O of the target conductor can be extracted from the cross-section. p and the centroid O of each adjacent conductor q Establish from O p Pointing to each O q The centroids are connected and sorted according to their circumferential angles. For two adjacent centroids, their angle bisectors are calculated, and the sector between the adjacent angle bisectors is taken as a sub-component of the target conductor facing a certain adjacent conductor.

[0067] Through the above processing, the target conductor W p It is divided into multiple conductor-conductor contact sub-assemblies. Each sub-assembly corresponds to only one adjacent conductor contact object, and the subsequently extracted cross-sectional area, contact width, volume resistance, and contact resistance can all be attributed to that contact object.

[0068] For the target wire W that is simultaneously in contact with terminal T pThe terminal contact sector is determined by identifying the target conductor's orientation towards the terminal. The terminal contact sector can be determined based on the direction of the terminal's inner wall center, the distribution of contact nodes between the conductor surface and the terminal surface, or the direction of the minimum distance from the conductor to the terminal's inner wall. Preferably, the terminal contact sector is divided into several sub-sectors according to angles, and the central area with the highest concentration of conductor-terminal contacts is selected as the effective sub-assembly for conductor-terminal contact.

[0069] After adopting the above circumferential partitioning, the same conductor is no longer treated as a whole in the calculation of all contact relationships, but is decomposed into multiple sub-components facing different contact objects. This process provides a basis for the spatial assignment of subsequent resistance components.

[0070] S3. Reconstruction of contact profiles and axial segmentation of adjacent sub-components:

[0071] The axial slicing and contact / non-contact region division logic for this step is attached. Figure 4 , attached Figure 4 This is a three-dimensional axial slice geometric diagram of adjacent sub-components, which intuitively demonstrates the spatial processing process of extracting boundary points along the axial direction of the press-fit structure, reconstructing the contact contour, and dividing the alternating contact and non-contact areas.

[0072] For any pair of adjacent sub-components C that have a contact relationship p and C q Multiple axial slice positions z1, z2, ..., z along the z-axis are set. k For each slice location, extract the cross-sectional boundary points of the two sub-components at that slice, and determine the contact profile points at that slice based on the overlap, distance, or contact criteria between the two cross-sectional boundaries.

[0073] All contact contour points are sorted along the axial coordinate, and an axial spacing threshold Δz is set. If the axial spacing between two adjacent contact contour points is less than Δz, they are considered to belong to the same continuous contact area; if the axial spacing is greater than or equal to Δz, they are considered to have a non-contact area. This results in contact areas C1, C2, ..., C1 arranged along the axial direction. a and non-contact areas N0, N1, ..., N a .

[0074] For the i-th contact region C i Its axial boundary is denoted as [z s,i ,z e,i The axial coordinates of the center contact node are: For the non-contact region N between two adjacent contact regions. j Its axial boundary is determined by the end position of the previous contact area and the start position of the next contact area.

[0075] S4. Extraction of topological feature parameters:

[0076] For each contact region and non-contact region, topological feature parameters are extracted. These topological feature parameters include the region's axial boundary, the region's center node, the center contact node, the effective conductive cross-sectional area, the equivalent contact width, the material resistivity, and the slice spacing.

[0077] When calculating the effective conductive cross-sectional area, for a certain axial slice position z, the centroid of the cross-section or any reference point is selected, and the boundary points of the sub-components at that slice are arranged in circumferential order to obtain an irregular polygon. This irregular polygon is divided into multiple triangles, and the areas of each triangle are summed to obtain the effective conductive cross-sectional area A(z) at that slice.

[0078] When calculating the equivalent contact width, the contact profile boundary points at two adjacent axial slices can be connected to form a contact profile element, and the average width of this contact profile element in the cross-sectional direction can be used as the equivalent contact width w. k For discrete contact points, the envelope width of the contact point in the tangential direction of the cross section can also be used as w. k .

[0079] S5. Identification and Calculation of Resistance Components:

[0080] This invention classifies resistive elements into three categories: interface contact resistors, contact area volume resistors, and non-contact area volume resistors.

[0081] Interface contact resistance refers to the resistance between two adjacent sub-components that transmit current through the contact interface. For the k-th axial slice element, let the equivalent contact area A... k =w k ·Δl k Equivalent circular contact radius The interfacial contact resistance corresponding to this axial slice unit can be expressed as:

[0082]

[0083] Where, ρ p ρ q The resistivity of the materials of two adjacent sub-components, w k For the equivalent contact width, Δl k This refers to the length of the axial slice element. When a contact area includes multiple axial slice elements, multiple R... c,k The interface contact resistance R of this contact area is synthesized according to the parallel relationship. c .

[0084] The contact area volume resistance refers to the resistance located within the contact area and belonging to the same sub-component's conductive path. For contact area C... i With the central contact node zc,i To define the boundaries, the volume resistance of the left contact area and the volume resistance of the right contact area can be calculated separately:

[0085]

[0086]

[0087] In discrete form, it can be expressed as:

[0088]

[0089]

[0090] Where L and R represent the sets of discrete axis segments located to the left and right of the central contact node, respectively.

[0091] The volume resistance of the non-contact area refers to the resistance located within the non-contact region and belonging to the same sub-component's conductive path. For an axial boundary of [z...] a,j ,z b,j The non-contact area N j The volume resistance of its non-contact area can be expressed as:

[0092]

[0093] Based on the above classification, contact interface transmission, contact area physical transmission, and non-contact area physical transmission each form a distinct resistive element.

[0094] S6. Construction of Local Resistor Networks:

[0095] This step involves two types of local resistor topologies, corresponding to the attached... Figure 5 Appendix Figure 6 Appendix Figure 5 This diagram illustrates the connection relationship between the volume resistance of the contact areas on both sides of the central contact node and the contact resistance at the interface between sub-components, using the equivalent resistance topology of a single contact area. Figure 6 This is a complete local network consisting of multiple contact and non-contact areas connected in series, demonstrating the axial connection between the volume resistance of the non-contact area and the contact areas on both sides.

[0096] For any contact area, an interface contact resistance R is set between the center contact nodes of two adjacent sub-components. c Within the same sub-component, connect the left contact area volume resistance R between the left boundary node of the contact area and the center contact node. bc,L Connect the center contact node to the right boundary node of the contact area using the volume resistance R of the right contact area. bc,R .

[0097] For any non-contact region, a volume resistance R is set between the two axial boundary nodes of the non-contact region.bn If a non-contact area is located between two contact areas, its two ends are connected to the contact area volume resistance of the adjacent contact area, respectively. Thus, a solid conductive path composed of the contact area volume resistance and the non-contact area volume resistance is formed along the axial direction, and a contact conductive path composed of the interface contact resistance is formed along the cross-boundary direction.

[0098] For a pair of adjacent sub-components, the above-mentioned physical conductive paths and contact conductive paths are connected in spatial order to obtain the local resistance network of the pair of adjacent sub-components.

[0099] S7. Complete resistor network splicing:

[0100] The topology of merging multiple local networks into a global network corresponds to the appendix. Figure 7 , attached Figure 7 The system demonstrates the complete resistance network formed by merging and eliminating redundant nodes based on the spatial location and shared nodes of all sub-component local networks, which can fully characterize all wire-to-wire and wire-to-terminal conduction paths.

[0101] Repeat steps S3 to S6 for all adjacent sub-components with contact relationships to obtain multiple local resistor networks. Based on the spatial position of each sub-component in the original press-fit structure, the relationship of shared wires or shared terminals, the axial region overlap relationship, and the boundary current input and output relationship, the multiple local resistor networks are spliced ​​into a complete resistor network.

[0102] During the assembly process, if multiple local resistance networks correspond to the same spatial node or equipotential node of the same conductive component, the corresponding nodes are merged; if multiple local resistance networks correspond to the same conductive component but different circumferential sub-assemblies, connection nodes or connection resistors are set according to the physical connection relationship. Thus, the complete resistance network can simultaneously characterize multiple wire-to-wire contact relationships and multiple wire-to-terminal contact relationships.

[0103] S8. Nodal Current Method for Solving and Classification of Equivalent Resistance Extraction:

[0104] Classification of equivalent resistance extraction logic corresponding to the appendix Figure 8 , attached Figure 8 All lossy components in the network are classified into four categories according to their physical properties, and the output results of the equivalent resistance of each category and the loss classification logic are presented intuitively.

[0105] The complete resistive network is transformed into a nodal admittance matrix G. For the resistive element e, the conductance... Based on the connection points at both ends of the resistor element, connect G... e Assemble it into the nodal admittance matrix G. Apply boundary conditions of input current, output current, and reference potential, and establish the nodal equations:

[0106]

[0107] Where U is the node voltage vector and I is the node injected current vector.

[0108] After obtaining U, for any resistive element e, if the voltages at its two ends are U a and U b Then the branch current I of the resistive element e and power P e They are respectively:

[0109]

[0110]

[0111] Based on the physical category of the resistive elements, all resistive elements are classified into four types: wire harness body resistors, terminal body resistors, wire harness-to-wire harness contact resistors, and wire harness-to-terminal contact resistors. For any physical category g, the power of all resistive elements in that category is summed, and the equivalent resistance of that category is obtained based on the total input current I0.

[0112]

[0113] This method allows us to obtain the total resistance and various equivalent resistance components. These equivalent resistance components can be used to determine the dominant source of resistance. For example, when the equivalent resistance of the wire harness body is relatively high, it indicates that the physical conductive path contributes significantly to the total resistance; when the equivalent resistance of the wire harness-terminal contact resistance is relatively high, it indicates that the contact state at the terminal interface may be the primary target for optimization.

[0114] Example 2: Application of multi-wire crimp terminals

[0115] In a specific application, the crimped electrical contact structure includes multiple copper wires and a terminal. Finite element crimping simulation is used to obtain the spatial coordinates of the surface nodes of each wire and terminal after crimping. First, the contact relationships between wires and between wires and terminals are identified based on the distance between surface nodes and the contact pressure results.

[0116] For a conductor located at the center of the structure, it may contact three or more adjacent conductors. After circumferential partitioning using the centroid angle bisector, the conductor is divided into multiple conductor-to-conductor contact sub-assemblies. For conductors near the inner wall of the terminal, they simultaneously contact the terminal and adjacent conductors. After terminal contact sector identification, valid conductor-to-terminal contact sub-assemblies are obtained, and the remaining area is further divided into conductor-to-conductor contact sub-assemblies.

[0117] Subsequently, the contact profile is extracted along the axial direction for each pair of adjacent sub-components, and the contact and non-contact regions are segmented based on axial continuity. Within each contact region, a central contact node is set, and the interface contact resistance and the volume resistance of the contact area on both sides of the central contact node are calculated separately; within each non-contact region, the volume resistance of the non-contact area is calculated. These resistive elements are connected into a local network, and then spliced ​​together to form a complete network.

[0118] After applying a total current I0 to the complete network, the nodal current method is used for solving. Based on the power and physical type of each resistive element, the harness body resistance, terminal body resistance, harness-to-harness contact resistance, and harness-to-terminal contact resistance can be obtained. If the analysis results show that the harness body resistance accounts for a high proportion, the wire material, wire cross-sectional area, or the deformation path of the solid after crimping can be optimized first. If the harness-to-terminal contact resistance accounts for a high proportion, the terminal covering structure, crimping height, terminal inner wall morphology, or crimping process parameters can be optimized first.

[0119] Therefore, this invention can not only be used to calculate the total resistance of a crimped electrical contact structure, but also to explain the physical components that make up the total resistance, and provide a more direct basis for structural optimization and failure analysis.

[0120] It should be noted that the contact criteria, circumferential partitioning rules, axial spacing thresholds, cross-sectional area calculation methods, and interface contact resistance calculation formulas in the above embodiments can all be adjusted according to the actual structure and data source. As long as contact object-oriented circumferential partitioning, axial contact / non-contact segmentation, and classification, identification, and equivalent extraction of interface contact resistance, contact area volume resistance, and non-contact area volume resistance are adopted, they should all fall within the protection scope of this invention.

Claims

1. A method for identifying the resistive components and equivalent modeling of a press-fit electrical contact structure, characterized in that, include: S1. Obtain the surface node spatial coordinates of each conductive component in the crimped electrical contact structure after crimping is completed, wherein the conductive component includes at least one wire and at least one terminal; Based on the spatial coordinates of the surface nodes, determine the distance and contact state between any two conductive parts, determine the contact relationship between each conductive part, and output a list of contact part pairs. S2. Guided by the contact objects in the contact part pair list, perform circumferential partitioning on each conductive part: divide the same conductive part into one or more sub-components facing different contact objects, each sub-component corresponding to a wire-to-wire contact relationship or a wire-to-terminal contact relationship, and output the geometric boundary data of each sub-component; S3. Based on the geometric boundary data of the sub-components, slice any pair of adjacent sub-components with a contact relationship along the axial direction of the press-fit structure, extract the boundary points of the sub-components at each slice to reconstruct the contact profile between adjacent sub-components; divide the contact profile according to the axial continuity criterion to obtain one or more contact areas arranged alternately along the axial direction and non-contact areas located between adjacent contact areas, and output the axial boundary and topological features of each area. S4. Based on the topological characteristics of each region, extract a set of parameters including the axial boundary of the region, the center node of the region, the center contact node of the contact region, the effective conductive cross-sectional area of ​​each axial slice position, and the equivalent contact width between adjacent slices, and output the geometric and material parameters for resistance calculation. S5. Based on the geometric and material parameters, identify and calculate three types of resistive elements: the resistance corresponding to the current transmitted between adjacent sub-components through the contact interface is identified as the interface contact resistance; the physical conductive path resistance located in the contact area and on both sides of the central contact node in the same sub-component is identified as the contact area volume resistance; and the physical conductive path resistance located in the non-contact area in the same sub-component is identified as the non-contact area volume resistance. S6. Using the center contact node of the contact area, the center node of the non-contact area, and the axial boundary node of the area as network nodes, the body resistance of the contact area and the body resistance of the non-contact area are connected in series along the axial direction of the conductive parts according to the current conduction path, and the interface contact resistance is connected in parallel between the center contact nodes of adjacent sub-components to form a local resistance network of adjacent sub-component pairs, and the topological connection relationship of the local network is output. S7. According to the spatial position relationship and shared node relationship of each local resistor network in the press-fit electrical contact structure, multiple local resistor networks are spliced ​​together, and redundant nodes are eliminated to obtain a complete resistor network. The node admittance matrix of the complete network is output. S8. Apply current input, output and reference potential boundary conditions to the complete resistor network, and solve for the branch current and power of each resistor element based on the nodal current method; According to the physical category to which the resistive elements belong, at least one equivalent resistive component is extracted from the following: wire harness body resistance, terminal body resistance, wire harness-to-wire harness contact resistance, and wire harness-to-terminal contact resistance.

2. The method for identifying and equivalently modeling the resistance components of a press-fit electrical contact structure according to claim 1, characterized in that, The specific steps for determining the contact relationship between each conductive component as described in S1 are as follows: For any two conductive components, set a node spacing threshold, a pressure threshold, read the binary contact identifier, and construct a signed distance field; if the region satisfies any comparison condition, the two conductive components are determined to be a pair of contact components.

3. The method for identifying and equivalently modeling the resistance components of a press-fit electrical contact structure according to claim 1, characterized in that, The method of dividing each conductive component into circumferential sections as described in S2 is as follows: when the conductors are in contact with each other, the sub-assemblies are divided by the angle bisector of the centroid connecting line; when the conductors are in contact with the terminal and other conductors at the same time, the terminal contact sector is first cut off as the terminal contact sub-assembly, and the remaining area is divided into conductor contact sub-assemblies.

4. The method for identifying and equivalently modeling the resistance components of a press-fit electrical contact structure according to claim 1, characterized in that, The axial continuity criterion described in S3 is as follows: sort the reconstructed contact contour points along the axial coordinates, configure the axial spacing threshold Δz, and classify adjacent contact contour points with an axial spacing less than Δz as the same contact area, otherwise determine that there is a non-contact area between them.

5. The method for identifying and equivalently modeling the resistance components of a press-fit electrical contact structure according to claim 1, characterized in that, In S4, the method for extracting the effective conductive cross-sectional area is as follows: the boundary points of the sub-components at the slice are enclosed into an irregular polygon, the triangles are subdivided, and the areas are accumulated to obtain the effective conductive cross-sectional area of ​​the slice.

6. The method for identifying and equivalently modeling the resistance components of a press-fit electrical contact structure according to claim 1, characterized in that, In S5, the volume resistance of the contact area and the volume resistance of the non-contact area are determined according to the conductive path length and the effective conductive cross-sectional area. For the volume resistance within any axial interval [z1, z2], the continuous form is: The discrete form is: Where ρ is the resistivity of the material of the corresponding conductive component, A(z) is the effective conductive cross-sectional area at the axial position z, and Δz m Let A be the length of the m-th discrete axis segment. m The effective conductive cross-sectional area corresponding to the m-th discrete axis segment; The interface contact resistance is determined based on the equivalent contact area. For the k-th axial slice unit, let the equivalent contact area A. k =w k ·Δl k Equivalent circular contact radius Then the interface contact resistance corresponding to the k-th axial slice unit is: Where, ρ p ρ q The resistivity of the materials of two adjacent sub-components, w k Let Δl be the equivalent contact width of the k-th axial slice element. k is the axial length of the k-th axial slice unit; when the same contact area includes multiple axial slice units, the interface contact resistances corresponding to the multiple axial slice units are combined in parallel to form the interface contact resistance of the contact area.

7. The method for identifying and equivalently modeling the resistance components of a press-fit electrical contact structure according to claim 1, characterized in that, In S6, the method for constructing the local resistor network is as follows: the axial midpoint of the contact area is taken as the central contact node, and the contact area body resistors are connected to both sides of the central contact node; the interface contact resistors are connected between the central contact nodes of adjacent sub-components; the non-contact area body resistors are connected to both ends of the non-contact area, and the contact areas are connected axially.

8. The method for identifying and equivalently modeling the resistance components of a press-fit electrical contact structure according to claim 1, characterized in that, In S8, the specific method for solving the complete resistive network and extracting the equivalent resistance component is as follows: using the nodal voltage equations Solve the complete resistive network; calculate the branch current and power based on the voltage difference between the nodes across the resistors and the resistance values ​​of the resistors; convert the total power of all resistors of the same physical category into equivalent resistance: Where g represents the wire harness body resistance, terminal body resistance, wire harness-to-wire harness contact resistance, or wire harness-to-terminal contact resistance. In the formula, G is the node admittance matrix, U is the node voltage vector, I is the node injected current vector, and I0 is the total input current. The equivalent resistance corresponding to category g. The power loss of the e-th resistive element is... This indicates that all the resistor elements belonging to category g are traversed.

9. A system for identifying and equivalently modeling the resistive components of a press-fit electrical contact structure, used to execute the method described in any one of claims 1 to 8, characterized in that, include: A geometric acquisition contact pairing unit is used to acquire the surface node spatial coordinates of each conductive part in the crimped electrical contact structure after crimping is completed. The conductive part includes at least one wire and at least one terminal. Based on the surface node spatial coordinates, the distance and contact state between any two conductive parts are determined, the contact relationship between each conductive part is determined, and a list of contact part pairs is output. The circumferential partitioning unit is used to partition each conductive part circumferentially based on the contact objects in the contact part pair list: the same conductive part is divided into one or more sub-components facing different contact objects, each sub-component corresponds to a wire-to-wire contact relationship or a wire-to-terminal contact relationship, and outputs the geometric boundary data of each sub-component. The axial slicing partitioning unit is used to slice any pair of adjacent sub-components with a contact relationship along the axial direction of the press-fit structure based on the geometric boundary data of the sub-components, extract the boundary points of the sub-components at each slice to reconstruct the contact contour between the adjacent sub-components; divide the contact contour according to the axial continuity criterion to obtain one or more contact regions arranged alternately along the axial direction and non-contact regions located between adjacent contact regions, and output the axial boundary and topological features of each region. The geometric parameter extraction unit is used to extract a set of parameters based on the topological characteristics of each region, including the axial boundary of the region, the center node of the region, the center contact node of the contact region, the effective conductive cross-sectional area of ​​each axial slice position, and the equivalent contact width between adjacent slices, and outputs geometric and material parameters for resistance calculation. A multi-resistance calculation unit is used to identify and calculate three types of resistive elements based on the geometric and material parameters: the resistance corresponding to the current transmitted between adjacent sub-components through the contact interface is identified as the interface contact resistance; the physical conductive path resistance located in the contact area and on both sides of the central contact node in the same sub-component is identified as the contact area volume resistance; and the physical conductive path resistance located in the non-contact area in the same sub-component is identified as the non-contact area volume resistance. The local resistance network construction unit is used to connect the contact area body resistance and the non-contact area body resistance in series along the axial direction of the conductive parts according to the current conduction path, using the center contact node of the contact area, the area center node of the non-contact area and the area axial boundary node as network nodes, and to connect the interface contact resistance in parallel between the center contact nodes of adjacent sub-components to form a local resistance network of adjacent sub-component pairs, and output the topological connection relationship of the local network. The complete resistance network splicing unit is used to splice multiple local resistance networks according to the spatial position relationship and shared node relationship of each local resistance network in the press-fit electrical contact structure, eliminate redundant nodes to obtain a complete resistance network, and output the node admittance matrix of the complete network. The network solution equivalent resistance extraction unit is used to apply current input, output and reference potential boundary conditions to the complete resistor network, and to obtain the branch current and power of each resistor element based on the nodal current method. According to the physical category to which the resistive elements belong, at least one equivalent resistive component is extracted from the following: wire harness body resistance, terminal body resistance, wire harness-to-wire harness contact resistance, and wire harness-to-terminal contact resistance.

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