Modeling calculation method for terminal resistance of wire harness for new energy automobile

Abstract

The invention discloses a modeling calculation method for the resistance of a wire harness terminal for a new energy automobile, and belongs to the technical field of dynamic modeling of the resistance of the wire harness terminal for the new energy automobile. In order to improve the accuracy of resistance modeling of the wire harness terminal for the new energy automobile, the method comprises the following steps: extracting a surface node space coordinate point set of N crimped wires and terminals; determining a contact domain range of the N wires and the terminal and extracting a node space coordinate point set of the N wires and the terminal; performing interpolation refinement processing on the node space coordinate point set in the contact domain range; calculating a contact contour point set in each parallel section along the axial direction of the wire; calculating an actual contact length, a contact width and a corresponding contact resistance according to the contact contour point set; and establishing a wire harness terminal resistance network model for the new energy automobile according to the spatial distribution of the crimped N wires and terminals. The method is suitable for resistance modeling calculation of the wire harness terminal for the new energy automobile, and calculation is accurate.

Description

Technical Field

[0001] The present invention belongs to the technical field of dynamic modeling of wire harness terminal resistance for new energy vehicles, and particularly relates to a modeling calculation method for wire harness terminal resistance for new energy vehicles. Background Art

[0002] With the rapid development of the new energy vehicle industry, as a core transmission component of the electrical system, the reliability of the high-voltage wire harness is directly related to the performance and safety of the whole vehicle. As a key link in connecting the wire and electrical equipment, the accurate calculation of the contact resistance of the wire harness terminal is of great significance for reducing energy consumption, improving system efficiency and avoiding the risk of local overheating. Traditional resistance modeling methods usually estimate the contact resistance through empirical formulas or simplified geometric models based on idealized assumptions (such as completely smooth contact surfaces, uniform pressure distribution, etc.), but ignore the influence of factors such as the microscopic deformation of the wire and terminal, surface roughness, and uneven distribution of multiple wires during the actual crimping process. Especially in the high-voltage and high-current scenarios of new energy vehicles, the complex morphology of the terminal contact surface will lead to a significant deviation between the actual contact area and the theoretical value, thus affecting the accuracy of resistance calculation. In the prior art, the research on the dynamic contour extraction of the contact domain after crimping of multiple wires, the local contact resistance distribution modeling, and the overall resistance network construction is not perfect, resulting in the calculation results being difficult to meet the high-precision design requirements and restricting the optimal design and reliability evaluation of the wire harness terminal. Summary of the Invention

[0003] The problem to be solved by the present invention is to improve the accuracy of the resistance modeling of the wire harness terminal for new energy vehicles, and a modeling calculation method for the wire harness terminal resistance for new energy vehicles is proposed.

[0004] To achieve the above object, the present invention is realized through the following technical solutions:

[0005] A modeling calculation method for the wire harness terminal resistance for new energy vehicles includes the following steps:

[0006] S1. Extract the spatial coordinates of the surface nodes of N wires and terminals after crimping, define the N wires and terminals after crimping as parts, and construct a set of spatial coordinate points of the surface nodes of the parts.

[0007] S2. Determine the contact domain range of different parts based on the set of spatial coordinate points of the surface nodes of the parts obtained in step S1, and extract the set of spatial coordinate points of the surface nodes of the parts within the contact domain range for the overlapping parts.

[0008] S3. Perform interpolation refinement processing on the set of spatial coordinate points of the surface nodes of the parts within the contact domain range obtained in step S2 to obtain the set of spatial coordinate points of the surface nodes of the parts within the contact domain range after interpolation refinement processing.

[0009] S4. Calculate the set of contact profile point sets in the parallel cross-section of the part within the contact domain along the axial direction of the wire for the set of spatial coordinate points of the surface nodes of the part within the contact domain obtained by interpolation refinement processing in step S3;

[0010] S5. Calculate the actual contact length, contact width between the contacting parts, and the contact resistance between the contacting parts for the set of contact profile point sets in the parallel cross-section of the part within the contact domain obtained in step S4;

[0011] S6. Based on the contact resistance between the contacting parts obtained in step S5, establish a wire harness terminal resistance network model for new energy vehicles according to the spatial distribution relationship of the N wires and terminals after crimping.

[0012] Further, in step S1, a three-dimensional solid model of the terminal, N wires, upper die, and lower die is established according to the actual working conditions, and the crimping process simulation of the terminal and the wire is carried out using finite element software, and then the spatial coordinate points of the surface nodes of the N wires and the terminal after crimping are extracted;

[0013] Define the N wires and the terminal after crimping as parts, and construct a set of spatial coordinate points of the surface nodes of the parts P k , and the expression is:

[0014]

[0015] where k is the kth part, k = 1 to N + 1, n k is the total number of surface node coordinates of the kth part, i is the ith surface node of the kth part, is the spatial coordinate point of the ith surface node of the kth part, is the X-axis coordinate point of the ith surface node of the kth part, is the Y-axis coordinate point of the ith surface node of the kth part, is the Z-axis coordinate point of the ith surface node of the kth part.

[0016] Further, the specific implementation method of step S2 includes the following steps:

[0017] S2.1. First, calculate the maximum and minimum values of the part on the x, y, and z coordinate axes respectively, and obtain the minimum point B of the set of spatial coordinate points of the surface nodes of the part k min and the maximum point B k max , and the expression is:

[0018] B k min =(minx i k ,miny ik , minz i k )

[0019] B k max = (maxx i k , maxy i k , maxz i k )

[0020] where min is the minimum value function and max is the maximum value function;

[0021] Then, with B k min and B k max as the two diagonal points of the cuboid, construct the set P of surface node spatial coordinate points of the part k of the bounding box;

[0022] If parts m and n, where 1 ≤ m, n ≤ N + 1 and m ≠ n, satisfy the following conditions:

[0023]

[0024] It is preliminarily judged that there is an overlapping part between parts m and n, otherwise there is no overlapping part;

[0025] Then determine the contact domain range of different parts to obtain parts m and n with overlapping parts preliminarily judged;

[0026] S2.2. For parts m and n with overlapping parts preliminarily judged obtained in step S2.1, calculate the convex hulls of the sets P of surface node spatial coordinate points of parts m and n respectively m and P n . If the vertices of the convex hull of P m are inside the convex hull of P n , determine that there is an overlapping part between P m , P n , and there is a contact domain between parts m and n;

[0027] S2.3. Assume that the Y - axis is the axial direction of each wire and terminal. Project the point sets P m and P n with contact domains onto the Y - axis, and respectively obtain the coordinate point sets Proj XZ (P m ) of part m in the XZ plane and the coordinate point set Proj XZ (P n ) of part n in the XZ plane. The expression is:

[0028]

[0029] Extract Proj XZ (P m ) and Proj XZ (P n ) to get the intersection Q mn , the expression is:

[0030] Q mn = [Proj XZ (P m )] ∩ [Proj XZ (P n )]

[0031] where ∩ is the intersection operator;

[0032] Map Q mn to the original surface node space coordinate point sets P m , P n of parts m and n respectively, to obtain the surface node space coordinate point set R m within the contact domain of part m, and the surface node space coordinate point set R n within the contact domain of part n. The expression is:

[0033]

[0034] Furthermore, the specific implementation method of step S3 is to calculate the interval length L m of part m on the X-axis and the interval length L x m on the Z-axis for the surface node space coordinate point set R z m . The expression is:

[0035]

[0036] If L x m ≥ L z m , then interpolate R m in the XY plane. If L x m < L z m , then interpolate R m in the YZ plane to obtain the surface node space coordinate point set S m of the part within the contact domain after interpolation refinement of part m. The expression is:

[0037]

[0038] Furthermore, the specific implementation method of step S4 includes the following steps:

[0039] S4.1. For the set of spatial coordinate points S of the surface nodes of the parts within the contact domain obtained by interpolating and refining parts m and n in step S3 m and S n extract the corresponding node sets S j m and S j n in each cross-section corresponding to the Y coordinate. The expression is:

[0040]

[0041] where y j is the set of parallel cross-sections along the Y axis;

[0042] For each cross-section y j calculate the distance d j m between all pairs of points in S j n and S j mn The expression is:

[0043]

[0044] S4.2. For all the distances between pairs of points obtained based on step S4.1 less than the given determination criterion ε, determine the points closest to the upper and lower limits in the X or Z direction. The expression is:

[0045]

[0046] where is the minimum value point closest to the X direction in the upper boundary set, is the maximum value point closest to the X direction in the upper boundary set, is the minimum value point closest to the Z direction in the lower boundary set, is the maximum value point closest to the Z direction in the lower boundary set, argmin represents calculating the value of j when x j or z j is the smallest, and argmax represents calculating the value of j when x j or z j is the largest;

[0047] S4.3. Based on the points closest to the upper and lower limits in the X or Z direction obtained in step S4.2, construct the set of contact profile points within the parallel cross-section of the part within the contact domain, and the upper boundary point set T mn-sand the lower boundary point set T mn-x The expression is as follows:

[0048] T mn-s ={t is =(x is , y is , z is ) | i = 1, 2,..., n s}}

[0049] T mn-x ={t ix =(x ix , y ix , z ix ) | i = 1, 2,..., n x}}

[0050] Among them, t is is the i-th upper boundary adjacent point, t ix is the i-th lower boundary adjacent point, n s is the total number of upper boundary adjacent points, n x is the total number of lower boundary adjacent points.

[0051] Furthermore, the specific implementation method of step S5 includes the following steps:

[0052] S5.1. Calculate the contact length l is , t (i+1)s and the contact width w ix , t (i+1)x of the spatial quadrilateral formed by the upper boundary adjacent points and the lower boundary adjacent points as vertices, and the expressions are as follows: i(i+1) mn i(i+1) mn

[0053]

[0054] S5.2. Calculate the contact resistance of a single spatial quadrilateral The expression is as follows:

[0055]

[0056]

[0057] Among them, ρ is the resistivity of the material, and r is the radius of the circular cross-section of the wire;

[0057] S5.3. Considering that the contact resistances of multiple spatial quadrilaterals are in parallel, obtain the contact resistance between the contact parts The expression is as follows:

[0058]

[0059] Further, the specific implementation method of step S6 is to obtain the contact resistance R between the contact parts c mn After that, according to the distribution relationship between the wires and the terminals after crimping, a wire harness terminal resistance network is established. Considering that the contact resistances between N wires and the terminals are in parallel, the wire harness terminal resistance R c has the following expression:

[0060]

[0061] Advantages of the present invention:

[0062] A modeling and calculation method for the terminal resistance of a wire harness for new energy vehicles according to the present invention, by extracting the spatial coordinates of the surface nodes of the wire and the terminal after crimping, combining the dynamic division of the contact domain range and the interpolation refinement process, accurately restores the microscopic contact morphology, and overcomes the problem of calculation deviation of the contact area caused by the simplified geometric model in the traditional method.

[0063] A modeling and calculation method for the terminal resistance of a wire harness for new energy vehicles according to the present invention, based on the layer-by-layer calculation of the contact profile point set of the axially parallel cross-section, can quantify the influence of local deformation, material properties and pressure distribution on the contact resistance, and provides refined modeling support for the non-uniform crimping scenario of multiple wires.

[0064] A modeling and calculation method for the terminal resistance of a wire harness for new energy vehicles according to the present invention, by establishing a spatial distribution resistance network model covering N wires and the terminals, can reflect the complex coupling relationship of the current path, significantly improve the overall resistance prediction accuracy, and is especially suitable for the multi-condition calculation of the high-voltage wire harness of new energy vehicles.

[0065] A modeling and calculation method for the terminal resistance of a wire harness for new energy vehicles according to the present invention can be directly applied to the design optimization of wire harness terminals, the verification of production process parameters and the reliability evaluation, provides a theoretical basis for reducing the contact resistance and suppressing the temperature rise, and helps to improve the energy efficiency and safety guarantee of the electrical system of new energy vehicles. Description of the drawings

[0066] Figure 1 is a flowchart of a modeling and calculation method for the terminal resistance of a wire harness for new energy vehicles according to the present invention;

[0067] Figure 2 is a schematic diagram of the wire harness terminal after crimping according to the present invention, where 1 is the first wire, 2 is the second wire, 3 is the third wire, 4 is the fourth wire, 5 is the fifth wire, 6 is the sixth wire, 7 is the seventh wire, and 8 is the terminal;

[0068] Figure 3 is a schematic diagram of the local contact profile of two parts according to the present invention;

[0069] Figure 4 Schematic diagram of the wire harness terminal resistance network established for the present invention. Detailed implementation manners

[0070] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners. It should be understood that the specific implementation manners described herein are only used to explain the present invention and are not used to limit the present invention, that is, the specific implementation manners described are only a part of the implementation manners of the present invention, rather than all of the specific implementation manners. Usually, the components of the specific implementation manners of the present invention described and shown in the accompanying drawings herein can be arranged and designed in various different configurations, and the present invention can also have other implementation manners.

[0071] Therefore, the detailed description of the specific implementation manners of the present invention provided in the accompanying drawings below is not intended to limit the scope of the claimed present invention, but merely represents the selected specific implementation manners of the present invention. Based on the specific implementation manners of the present invention, all other specific implementation manners obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

[0072] To further understand the content, features and effects of the present invention, the following specific implementation manners are exemplified and are accompanied by Figure 1 - Attachment Figure 4 The details are as follows:

[0073] Example 1:

[0074] A modeling calculation method for the wire harness terminal resistance of new energy vehicles includes the following steps:

[0075] S1. Extract the surface node space coordinates of N wires and terminals after crimping, define the N wires and terminals after crimping as parts, and construct a surface node space coordinate point set of the parts;

[0076] Furthermore, in step S1, a three-dimensional solid model of the terminal, N wires, upper die and lower die is established according to the actual working conditions, the finite element software is used to simulate the crimping process of the terminal and the wire, and then the surface node space coordinates of the N wires and terminals after crimping are extracted;

[0077] Define the N wires and terminals after crimping as parts, and construct a surface node space coordinate point set P k , and the expression is:

[0078]

[0079] where k is the kth part, k = 1 to N + 1, nk is the total number of surface node coordinates of the k-th part, and i is the i-th surface node of the k-th part. is the spatial coordinate point of the i-th surface node of the k-th part. is the X-axis coordinate point of the i-th surface node of the k-th part. is the Y-axis coordinate point of the i-th surface node of the k-th part. is the Z-axis coordinate point of the i-th surface node of the k-th part;

[0080] S2. Determine the contact domain range of different parts based on the set of spatial coordinate points of the surface nodes of the parts obtained in step S1, and extract the set of spatial coordinate points of the surface nodes of the parts within the contact domain for overlapping parts;

[0081] Furthermore, the specific implementation method of step S2 includes the following steps:

[0082] S2.1. First, calculate the maximum and minimum values of the part on the x, y, and z coordinate axes respectively to obtain the minimum point B of the set of spatial coordinate points of the surface nodes of the part k min and the maximum point B k max . The expression is:

[0083] B k min =(minx i k , miny i k , minz i k )

[0084] B k max =(maxx i k , maxy i k , maxz i k )

[0085] where min is the minimum value function and max is the maximum value function;

[0086] Then, with B k min and B k max as the two diagonal points of the cuboid, construct the bounding box of the set of spatial coordinate points P k of the surface nodes of the part;

[0087] If parts m and n, 1 ≤ m, n ≤ N + 1 and m ≠ n, satisfy the following conditions:

[0088]

[0089] It is preliminarily determined that there is an overlapping part between part m and part n; otherwise, there is no overlapping part.

[0090] Then, determine the contact domain range of different parts to obtain part m and part n whose preliminary judgment shows overlap.

[0091] S2.2. For part m and part n whose preliminary judgment shows overlap obtained in step S2.1, calculate the set of spatial coordinate points P of the surface nodes of part m and part n respectively m and P n of the convex hull. If the vertices of the convex hull of P m are inside the convex hull of P n , determine that there is an overlapping part between P m and P n , and there is a contact domain between part m and part n.

[0092] S2.3. Assume that the Y-axis is the axial direction of each wire and terminal, project the point sets P m and P n with a contact domain onto the Y-axis, and respectively obtain the set of coordinate points Proj XZ (P m ) of part m in the XZ plane and the set of coordinate points Proj XZ (P n ) of part n in the XZ plane. The expression is:

[0093]

[0094] Extract the intersection Q XZ (P m ) and Proj XZ (P n ), and the expression is: mn Q

[0095] Q mn =[Proj XZ (P m )]I[Proj XZ (P n )]

[0096] where I is the intersection operator;

[0097] Map Q mn to the original sets of spatial coordinate points P of the surface nodes of parts m and n respectively m and P n , and obtain the set of spatial coordinate points R m of the surface nodes within the contact domain of part m and the set of spatial coordinate points R of the surface nodes within the contact domain of part nn , the expression is:

[0098]

[0099] S3. Perform interpolation refinement on the set of spatial coordinate points of the surface nodes of the parts within the contact domain obtained in step S2 to obtain the set of spatial coordinate points of the surface nodes of the parts within the contact domain after interpolation refinement;

[0100] Further, the specific implementation method of step S3 is to perform interpolation on the set of spatial coordinate points R of the surface nodes within the contact domain of part m m Calculate the interval length L of part m on the X-axis x m and the interval length L on the Z-axis z m , the expression is:

[0101]

[0102] If L x m ≥L z m , then perform interpolation on R in the XY plane. If L m x m <L z m , then perform interpolation on R in the YZ plane to obtain the set of spatial coordinate points S of the surface nodes of the parts within the contact domain of part m after interpolation refinement m m , the expression is:

[0103]

[0104]

[0105] S4. Calculate the set of contact profile points within the parallel cross-section of the part within the contact domain along the axial direction of the wire for the set of spatial coordinate points of the surface nodes of the part within the contact domain after interpolation refinement obtained in step S3;

[0106] Further, the specific implementation method of step S4 includes the following steps:

[0106] S4.1. For the set of spatial coordinate points S of the surface nodes of the parts within the contact domain of part m and part n after interpolation refinement obtained in step S3 m , S n , extract the corresponding node sets S j m and S j n , the expression is:

[0107]

[0108] Among them, y j is a set of parallel cross-sections along the Y-axis;

[0109] For each cross-section y j , calculate S j m and S j n the distances between all pairs of points in The expression is:

[0110]

[0111] S4.2. For all the distances between pairs of points obtained based on step S4.1 points with distances less than the given determination criterion ε, determine the points closest to the upper and lower limits in the X direction or Z direction. The expression is:

[0112]

[0113] Among them, is the minimum value point closest to the X direction in the upper boundary set, is the maximum value point closest to the X direction in the upper boundary set, is the minimum value point closest to the Z direction in the lower boundary set, is the maximum value point closest to the Z direction in the lower boundary set, argmin represents calculating the value of j when x j or z j is the smallest, argmax represents calculating the value of j when x j or z j is the largest;

[0114] S4.3. Based on the points closest to the upper and lower limits in the X direction or Z direction obtained in step S4.2, construct a set of contact profile points within the parallel cross-section of the part within the contact domain. The upper boundary point set T mn-s and the lower boundary point set T mn-x are expressed as:

[0115] T mn-s ={t is =(x is ,y is ,z is )|i = 1, 2,..., n s}

[0116] T mn-x ={t ix =(x ix ,y ix ,z ix)|i = 1, 2, ..., n x [[ID=2}}

[0117] Among them, t is is the i-th upper boundary adjacent point, t ix is the i-th lower boundary adjacent point, n s is the total number of upper boundary adjacent points, n x is the total number of lower boundary adjacent points.

[0118] S5. For the set of contact profile points in the parallel cross-section of the parts within the contact area obtained in step S4, calculate the actual contact length, contact width between the contacting parts, and the contact resistance between the contacting parts;

[0119] Furthermore, the specific implementation method of step S5 includes the following steps:

[0120] S5.1. Calculate the contact length l is and l (i+1)s of the spatial quadrilateral formed by the upper boundary adjacent points t ix and t (i+1)x and the lower boundary adjacent points t i(i+1) mn and the contact width w i(i+1) mn , and the expression is:

[0121]

[0122] S5.2. Calculate the contact resistance of a single spatial quadrilateral The expression is:

[0123]

[0124] Among them, ρ is the resistivity of the material, and r is the radius of the circular cross-section of the wire;

[0125] S5.3. Considering that the contact resistances of multiple spatial quadrilaterals are in parallel relationship, obtain the contact resistance between the contacting parts, and the expression is:

[0126]

[0127] S6. Based on the contact resistance between the contacting parts obtained in step S5, according to the spatial distribution relationship of the N wires and terminals after crimping; establish a wire harness terminal resistance network model for new energy vehicles;

[0128] Furthermore, the specific implementation method of step S6 is to obtain the contact resistance R c mnAfter that, according to the distribution relationship between each wire and the terminal after the crimping is completed, a wire harness terminal resistance network is established. Considering that the contact resistances between N wires and the terminal are in parallel, the wire harness terminal resistance R c The expression is:

[0129]

[0130] It should be noted that relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0131] Although the present application has been described above with reference to specific embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the various features in the specific embodiments disclosed in the present application can be combined with each other in any way, and the exhaustive description of these combinations is not given in this specification only for the sake of saving space and resources. Therefore, the present application is not limited to the specific specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A modeling and calculation method for the resistance of wiring harness terminals for new energy vehicles, characterized in that: The steps include: S1. extracting the surface node space coordinates of the N crimped wires and terminals, defining the N crimped wires and terminals as parts, and constructing the surface node space coordinate point set of the parts; S2. Determine the contact domain range of different parts based on the surface node space coordinate point set of the parts obtained in step S1, and extract the surface node space coordinate point set of the parts within the contact domain range for the overlapping parts; S3. Performing interpolation and refinement processing on the surface node space coordinate point set of the part within the contact domain obtained in step S2 to obtain the surface node space coordinate point set of the part within the contact domain that has been processed by interpolation and refinement; S4. For the surface node space coordinate point set of the part within the contact domain range obtained by interpolation and refinement in step S3, the contact contour point set in the parallel section of the part within the contact domain range is calculated along the axial direction of the wire; S5. Calculate the actual contact length, contact width and contact resistance between the contact parts for the contact contour point set in the parallel cross section of the parts within the contact domain obtained in step S4; S6. Based on the contact resistance between the contact parts obtained in step S5 and the spatial distribution relationship between the N crimped wires and the terminals, a resistance network model of the wiring harness terminals for new energy vehicles is established.

2. A modeling and calculation method for the resistance of wiring harness terminals for new energy vehicles according to claim 1, characterized in that: Step S1: Establish a three-dimensional solid model of the terminal, N wires, an upper mold, and a lower mold according to actual working conditions, use finite element software to simulate the crimping process of the terminal and the wire, and then extract the surface node space coordinates of the crimped N wires and the terminal; Define the N crimped wires and terminals as parts, and construct the surface node space coordinate point set P of the parts. k , the expression is: Where k is the kth part, k = 1 ~ N + 1, n k is the total number of surface node coordinates of the kth part, i is the i-th surface node of the kth part, is the spatial coordinate point of the i-th surface node of the k-th part, is the X-axis coordinate point of the i-th surface node of the k-th part, is the Y-axis coordinate point of the i-th surface node of the k-th part, is the Z-axis coordinate point of the i-th surface node of the k-th part.

3. A modeling and calculation method for the resistance of wiring harness terminals for new energy vehicles according to claim 2, characterized in that: The specific implementation method of step S2 includes the following steps: S2.

1. First, calculate the maximum and minimum values ​​of the part on the x, y and z coordinate axes respectively, and obtain the minimum point B of the surface node space coordinate point set of the part k min and maximum point B k max , the expression is: B k min =(minx i k , mines i k ,min i k ) B k max =(maxx i k ,maxy i k ,maxz i k ) Among them, min is the minimum function and max is the maximum function; Then with B k min and B k max For the two diagonal points of the cuboid, construct the surface node space coordinate point set P of the part k The bounding box of If part m and part n, 1≤m, n≤N+1 and m≠n, the following conditions are met: It is preliminarily determined that part m and part n have overlapping parts, otherwise there is no overlapping part; Then, the contact domain ranges of different parts are determined, and a preliminary judgment is made on the overlapping parts m and n; S2.

2. For the parts m and n that are initially judged to overlap in step S2.1, calculate the surface node space coordinate point set P of parts m and n respectively. m and P n The convex hull of m The convex hull vertex is at P n In the convex hull of m , P n There is an overlapping part, and there is a contact domain between part m and part n; S2.

3. Assuming that the Y axis is the axial direction of each wire and terminal, there will be a point set P in the contact domain m and P n Project to the Y axis to obtain the coordinate point set Proj of part m on the XZ plane XZ (P m ), the coordinate point set Proj of part n in the XZ plane XZ (P n ), the expression is: Extract Proj XZ (P m ) and Proj XZ (P n ) mn , the expression is: Q mn =[Proj XZ (P m )]I[Proj XZ (P n )] Among them, I is the intersection operator; Q mn The original surface node space coordinate point set P mapped to parts m and n respectively m , P n , obtain the surface node space coordinate point set R within the contact domain of part m m , the surface node space coordinate point set R within the contact domain of part n n , the expression is:

4. A modeling and calculation method for the resistance of wiring harness terminals for new energy vehicles according to claim 3, characterized in that: The specific implementation method of step S3 is to calculate the surface node space coordinate point set R within the contact domain of part m m Calculate the interval length L of part m on the X axis x m and the interval length L on the Z axis z m , the expression is: If L x m ≥L z m , then in the XY plane, m Interpolation, if L x m <L z m , then in the YZ plane, for R m Interpolation is performed to obtain the surface node space coordinate point set S of the part within the contact domain of the interpolation refinement of part m m , the expression is:

5. A modeling and calculation method for the resistance of wiring harness terminals for new energy vehicles according to claim 4, characterized in that: The specific implementation method of step S4 includes the following steps: S4.

1. The surface node space coordinate point set S of the parts within the contact domain of the interpolated and refined parts m and n obtained in step S3 m , S n , extract the corresponding node set S at each cross section corresponding to the Y coordinate j m and S j n , the expression is: Among them, y j is a set of parallel sections along the Y axis; For each section y j , calculate S j m and S j n The distance between all points in The expression is: S4.

2. For the distances between all the points obtained in step S4.1 For the point that is smaller than the given judgment standard ε, determine the point closest to the upper and lower limits in the X direction or Z direction. The expression is: in, is the minimum point in the upper boundary set closest to the X direction, is the maximum value point closest to the X direction in the upper boundary set, is the minimum point in the lower boundary set closest to the Z direction, is the maximum value point in the lower boundary set that is closest to the Z direction. arg min indicates the calculation of x j or j The value of j when it is minimum, arg max means calculating x j or j The value of j at maximum; S4.

3. Based on the points closest to the upper and lower limits in the X or Z direction obtained in step S4.2, a contact contour point set in the parallel section of the part within the contact domain is constructed, and a contact contour upper boundary point set T mn-s and the lower boundary point set T mn-x The expression is: T mn-s ={t is =(x is ,y is ,z is )|i=1,2,...,n s } T mn-x ={t ix =(x ix ,y ix ,z ix )|i=1,2,...,n x } Among them, t is is the i-th upper boundary adjacent point, t ix is the adjacent point of the ith lower boundary, n s is the total number of adjacent points on the upper boundary, n x is the total number of adjacent points to the lower boundary.

6. A modeling and calculation method for the resistance of wiring harness terminals for new energy vehicles according to claim 5, characterized in that: The specific implementation method of step S5 includes the following steps: S5.

1. Calculate the above boundary adjacent points t is ,t (i+1)s and the lower boundary adjacent point t ix ,t (i+1)x The contact length l of the space quadrilateral formed by the vertices i(i+1) mn and contact width w i(i+1) mn , the expression is: S5.

2. Calculation of the Contact Resistance of a Single Spatial Quadrilateral The expression is: Where ρ is the resistivity of the material and r is the radius of the circular cross section of the conductor; S5.

3. Considering that the contact resistances of multiple spatial quadrilaterals are in parallel, the contact resistance between the contact parts is obtained The expression is:

7. A modeling and calculation method for the resistance of wiring harness terminals for new energy vehicles according to claim 6, characterized in that: The specific implementation method of step S6 is to obtain the contact resistance R between the contact parts. c mn Finally, according to the distribution relationship between the crimped wires and the terminals, the wiring harness terminal resistance network is established. Considering the contact resistance between the N wires and the terminals is in parallel, the wiring harness terminal resistance R is obtained. c The expression is:

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