Intelligent digital modeling method for laying process of metal rubber component

Abstract

The invention discloses an intelligent digital modeling method for a laying process of a metal rubber component, and belongs to the technical field of computational simulation. The method comprises the following steps: firstly, establishing a straight line center track path of a spiral metal wire, establishing a spiral line center path of the spiral metal wire around the straight line center track path, then generating a grid of the metal rubber based on the path, and finally generating a solid three-dimensional model of the metal rubber. According to the intelligent digital modeling method, the finite element method and the computer graphics theory are combined to solve the intelligent digital modeling problem of the metal rubber component laying process, and intelligent digital modeling of the metal rubber component laying process can be rapidly achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of computational simulation, and in particular is an intelligent digital modeling method for a metal rubber component laying process. Background Art

[0002] Metal rubber is an elastic porous material with nonlinear stiffness and high damping. Inside the metal rubber, metal wires are intertwined to form a spatial network structure, which is similar to the macromolecular structure of rubber, and has rubber-like elasticity and damping properties. Metal rubber is often used in the aerospace field to solve problems such as vibration, sealing, and filtration in harsh space environments. Common metal rubber manufacturing processes include: laying, winding, and weaving.

[0003] At present, 3D modeling technology is widely used in the field of industrial manufacturing. However, due to the complexity of the actual manufacturing method of metal rubber, existing commercial software cannot directly model it, and there are also the following disadvantages: on the one hand, the spiral metal wire in the metal rubber cannot be accurately modeled; on the other hand, manual adjustment is required during modeling, which is time-consuming and laborious. Based on the above disadvantages, it is increasingly important to study a rapid modeling method for metal rubber components.

[0004] Therefore, an intelligent digital modeling method for the laying process of metal rubber components is established. By applying the mature finite element theory and graphics theory, the metal rubber three-dimensional model can be effectively established. Not only can the metal rubber entity three-dimensional model be automatically established at a relatively low cost, but the model can also be controlled more accurately, which can provide more effective guidance for subsequent design, simulation and optimization. Summary of the invention

[0005] The present invention discloses an intelligent digital modeling method for a metal rubber component laying process. The method combines finite element theory with graphics theory to solve related problems of intelligent digital modeling for a metal rubber component laying process, and can quickly realize intelligent digital modeling for a metal rubber component laying process.

[0006] The technical solution provided by the present invention to solve the above technical problems is: an intelligent digital modeling method for the laying process of metal rubber components, comprising the following steps:

[0007] S1, generating the initial center trajectory path point of the metal rubber component laying process;

[0008] S2, performing plane correction, vertical correction and smoothing processing on the path points of the initial center trajectory;

[0009] S3, interpolating the corrected laying center trajectory path points to generate the center trajectory points of the metal rubber component;

[0010] S4. Generate the helical center trajectory of the metal rubber component based on the central trajectory points;

[0011] S5. Surrounding the helical center trajectory, generate helical nodes and elements through an arithmetic progression, and then form a grid to complete the intelligent digital modeling of the metal rubber component laying process;

[0012] A further technical solution is that the specific implementation method of the step S1 is as follows:

[0013] S11. Set the initial parameters: For the pegboard as Figure 2 shown, it is necessary to set the number s of pins, the central coordinates C i (i = 1, 2,..., s) of the pins, the allowable laying radius r of the attached circles of the pins, the pin path w that the multi-layer laying trajectory needs to pass through, as Figure 2 The pin path shown by the thick solid line is pin 1 - pin 2 - pin 4 - pin 5...,, the interpolation spacing d, the vertical coordinate z0 of the starting laying layer, the distance delta between every two laying layers, the vertical correction height h (h < delta), the number of laying layers i, and the vertical coordinate z of each laying layer i = z0 + delta × (i - 1), etc.;

[0014] S12. In the rectangular coordinate system, there are s pins in total, and the pin path is Generate the position of the initial center trajectory path point according to the pin path and the relative position of the positioning pins:

[0015] For the first segment of the path, that is, segment: If pin a3 is above the line a1a2, then the corresponding trajectory takes the lower one of the external common tangents of the two attached circles ( Figure 3 (a)) of the tangent point; if pin a3 is below the line a1a2, then the corresponding trajectory takes the upper one of the external common tangents of the two attached circles ( Figure 3 (b)) of the tangent point.

[0016] For the middle segment of the path, that is, segment, i = 1, 2, 3, 4,..., s - 2: If a i-1 is below the line a i a i+1 below, a i+2 is above the line, then the corresponding trajectory takes Figure 3 (c) shown as the tangent point of the internal common tangent of the two attached circles; if a i-1 is above the line a i a i+1 above, a i+2 is below the line, then the corresponding trajectory takes Figure 3 (d) shown as the tangent point of the internal common tangent of the two attached circles; if ai-1 、a i+2 All in straight line a i a i+1 Below, the corresponding trajectory is the upper one of the external common tangent lines of the two attached circles ( Figure 3 (e)) is the point of tangency; if a i-1 、a i+2 All in straight line a i a i+1 Above, the corresponding trajectory is the lower one of the two subordinate circles' external tangents ( Figure 3 (f)) of the tangent point.

[0017] For the end of the path, Section: If pin a s-2 On the straight line a s-1 a s Above, the corresponding trajectory is the lower one of the two external tangent lines of the attached circles ( Figure 3 (g)) tangency point; if the pin a s-2 On the straight line a s-1 a s Below, the corresponding trajectory is the upper common tangent line of the two attached circles ( Figure 3 (h)) tangent point;

[0018] S13, integrating all the above-mentioned tangent points to form an initial center trajectory path point;

[0019] A further technical solution is that the specific implementation method of step S2 is:

[0020] S21, plane correction;

[0021] If the initial track segment passes through some pin attached circles during the laying process, the corresponding track needs to be corrected in the plane. Figure 4 The method shown is to change the line segment to be corrected into a line segment-a minor arc-a line segment, and the radius of the minor arc is the same as the radius of the pin attachment circle;

[0022] S22, vertical correction;

[0023] During paving, the current track may cross or overlap with the previous track in the same paving layer. In this case, the vertical coordinates of the current track need to be changed. When the crossing or overlapping ends, the path returns to the paving layer. The vertical corrections required include the vertical corrections of the straight line segment and the vertical corrections of the arc segment.

[0024] For vertical correction of straight line segments, such as Figure 5As shown in (a), the tracks intersect at point K. The current laying track needs to be corrected vertically. A circle is made with the track intersection point K as the center and the allowable laying radius r of the pin attachment circle as the radius. The intersection points of this circle with the current laying track are B' and C'. Another circle is made with 2r as the radius. The intersection points of this circle with the current laying track are A and D. Then the vertical coordinates of B' and C' are changed to z i =z0+delta×i-1)+h, and obtain B and C, and finally obtain the coordinates of the trajectory points A, B, C and D after vertical correction.

[0025] S23, smoothing processing;

[0026] For the non-guidable points (sharp points) formed by connecting straight lines and arcs at the plane correction and vertical correction in the initial trajectory, arc smoothing is needed to be used for transition removal; for the sharp points in the plane correction, plane arc transition is used; for the sharp points in the vertical correction, space arc transition is used.

[0027] Through Figure 6 The smoothing process shown in the figure solves the cusp problem, changes the path ADE into the path AMNE, and replaces the cusp D with the arc MN to ensure that the straight line segment and the arc segment can transition smoothly;

[0028] The specific method of plane arc transition is: take the pin C as the center of the circle and make a circle 1 with a radius of twice the allowable laying radius r of the pin attached circle, offset the line segment AD in the direction away from the center of the circle C by r to obtain the line segment A′D', the intersection point of the line segment A′D' and the circle 1 is P, project P to the line segment AD, the projection point is M, let the midpoint of PC be N, and finally obtain the coordinates of the trajectory points A, M, N and E after smoothing;

[0029] The specific method of spatial arc transition is: first, the path to be smoothed is transformed to the horizontal plane by using the Rodrigues rotation formula, then the plane arc transition is performed, and then the coordinates of the points after the plane arc transition are rotated back to the original plane by using the Rodrigues rotation formula;

[0030] A further technical solution is that the specific implementation method of step S3 is:

[0031] S31. If a straight line segment is used to connect every two adjacent initial path points, the length of the line segment needs to be calculated, and then the number of interpolation points m is determined according to the required interpolation spacing d, and then the coordinates of each interpolation point are calculated by linear interpolation. The formula used is as follows:

[0032]

[0033] m is the number of interpolation points, x A ,y Aare the x- and y-coordinates of the starting and ending points of the line segment. B ,y B are the x- and y-coordinates of the end points of the line segment, and d is the interpolation spacing.

[0034] S32, if every two adjacent initial path points are connected by arc segments, it is necessary to calculate the length of the arc, and then determine the number and coordinates of the interpolation points according to the required interpolation spacing;

[0035] S33, integrating all interpolation points and initial path points to generate the center trajectory point of the paving path, see Figure 7 ;

[0036] A further technical solution is that the specific implementation method of step S4 is:

[0037] S41. In the global coordinate system, a cylindrical spiral is generated between every two center trajectory path points. The formula is as follows:

[0038]

[0039] Where θ=ωt, ω is the angular velocity, h is the pitch, β is the helix angle, the right helix takes a positive sign, and the left helix takes a negative sign.

[0040] S42, moving the cylindrical helix in the global coordinate system to the local coordinate system by translation and rotation (making the Z axis of the global coordinate system coincide with the Z axis of the local coordinate system);

[0041] Calculate the vectors between the two adjacent points of the interpolation point and set it as the Z-axis direction of the local coordinate system; calculate the rotation matrix R and translation matrix T between the Z-axes of the two coordinate systems, and the calculation formula for the coordinates of the points on the real spiral line is as follows:

[0042] The coordinates of a point on the real helix = T × R × the coordinates of a point on the cylindrical helix in the global coordinate system.

[0043] Rotation matrix R: calculated by Rodrigues rotation formula;

[0044] Translation matrix T: Where x, y and z are the coordinates of the interpolation point;

[0045] The final spiral path is shown in Figure 8 ;

[0046] A further technical solution is that the specific implementation method of step S5 is:

[0047] S51. Metal rubber is made of metal wire, and the cross section of the metal wire is circular. Therefore, the mesh division takes the central trajectory interpolation point as the center point, and generates the surrounding nodes (counterclockwise) around each center point through an arithmetic sequence, and then generates a unit. The nodes in the unit need to be sorted counterclockwise accordingly;

[0048] First, set the circular section radius r0, the number of nodes per circle on the circumference a, the number of grid division circles b, and the number of layers l (i.e. the number of center points).

[0049] The node coordinates of the center point are the coordinates of the center trajectory interpolation point, and the node number of the center point uses the following formula:

[0050] n i =n1+(a×b+1)×(c i -1) (i=1,2,…,l)

[0051] Where n is the node number, a is the number of nodes on the circumference, b is the number of mesh divisions, and c is the number of nodes on the circumference. i is the i-th center point.

[0052] Then generate the coordinates and numbers of the remaining nodes around the central node. The coordinates of the remaining nodes are calculated using the following formula:

[0053]

[0054] Where x0, y0 and z0 are the coordinates of the center node, x, y and z are the coordinates of the nodes to be generated. is the radius of the i-th circle where the node is located, b is the number of grid division circles, and β=(j-1)θ is the circumferential angle corresponding to the j-th node.

[0055] The surface formed by each layer of nodes needs to be rotated accordingly around the corresponding center point.

[0056] The remaining nodes are numbered as follows:

[0057] For the nodes in the first circle of the first layer, the nodes in the horizontal direction are numbered 2, and the remaining nodes in the circle are sorted counterclockwise and numbered 3, 4, …, a+1; for the nodes in the kth circle of the first layer, the nodes in the horizontal direction are numbered 2+5×(k-1), and the remaining nodes in the circle are sorted counterclockwise and numbered 2+5×(k-1)+1, 2+5×(k-1)+2, …, 2+5×(k-1)+(a-1); and the same goes for the remaining circles.

[0058] S52, generate Fig. 9The units and nodes shown in the figure include pentahedral units with a center point, a×(l-1) in total, and the rest are hexahedral units, a×(l-1)×(b-1) in total. The unit numbers are also generated in a counterclockwise manner. First, all pentahedral units are coded. The pentahedron composed of nodes 1-2-3-12-13-14 is unit 1, and the pentahedron composed of nodes 1-3-4-12-14-15 is unit 2, ..., counterclockwise, and so on; then all hexahedral units are coded. The hexahedron composed of nodes 2-7-8-3-13-18-19-14 is unit a×(l-1)+1, and the hexahedron composed of nodes 3-8-9-4-14-19-20-15 is unit a×(l-1)+2, ..., counterclockwise, and so on, until all units are coded.

[0059] S53, the grid is composed of six-node pentahedral elements and eight-node hexahedral elements. For the six-node pentahedral elements, the shape function adopts the following formula:

[0060]

[0061] Among them, L i is the area of ​​the triangle.

[0062] For eight-node hexahedral elements, the shape function uses the following formula:

[0063]

[0064] In the formula, (ξ i ,η i ,ζ i ) represents the coordinates of node i of the unit in the (ξ,η,ζ) coordinate system.

[0065] like Fig.10 As shown in Figure 2, different numbers of elements and nodes can be generated for the model. The final metal rubber model is shown in Figure 2. Fig.11 , see the enlarged view of the local grid Fig.12 .

[0066] The beneficial effects of the present invention are as follows: the present invention calculates the coordinates of each trajectory based on MATLAB to form the coordinates of the unit and the node, and then realizes the establishment of the finite element model through Qt. Different from the local three-dimensional model of metal rubber established by beam unit simulation in the past, the present invention adopts solid unit for modeling, which can simulate the actual structure of metal rubber more accurately, so that the practical problems such as friction and wear, contact state and fatigue cracking between the metal wires inside the metal rubber can be considered. The present invention can generate the precise coordinates of each node and unit, and the user can flexibly modify the number of nodes and units according to the needs, and can quickly establish models with different numbers of grids to meet the analysis requirements of different precision requirements. The present invention realizes the flexible adjustment of parameters such as the metal rubber laying process path and the number of laying layers through intelligent digital modeling, eliminates the tedious process of manual geometric modeling, facilitates the rapid adjustment of structural design, and can realize the process optimization of any laying path, which provides great convenience for subsequent simulation optimization and can significantly improve the design efficiency and the expansibility of the model. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 It is a flow chart of an intelligent digital modeling method for a metal rubber component laying process of the present invention;

[0068] Figure 2 It is a schematic diagram of parameters used in the metal rubber laying process of the present invention;

[0069] Figure 3 It is a schematic diagram of the laying track direction of the metal rubber laying process of the present invention;

[0070] Figure 4 It is a schematic diagram of the plane correction of the laying track of the metal rubber laying process of the present invention;

[0071] Figure 5 It is a schematic diagram of vertical correction of the laying track of the metal rubber laying process of the present invention;

[0072] Figure 6 It is a schematic diagram of smoothing the laying track of the metal rubber laying process of the present invention;

[0073] Figure 7 It is the central trajectory path point of different metal rubber models obtained by the present invention through intelligent digital modeling;

[0074] Figure 8 It is a spiral path diagram of different metal rubber models obtained by the present invention through intelligent digital modeling;

[0075] Fig. 9 It is a schematic diagram of units and nodes generated by the present invention through intelligent digital modeling;

[0076] Fig.10 These are schematic diagrams of different numbers of units and nodes obtained through intelligent digital modeling of the present invention;

[0077] Fig.11 These are different metal rubber models obtained through intelligent digital modeling of the present invention;

[0078] Fig.12 This is a partial mesh enlarged view of the metal rubber model obtained through intelligent digital modeling of the present invention; Detailed implementation manners

[0079] Next, the technical solution of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0080] As Figure 1 shown, the present invention provides an intelligent digital modeling method for the laying process of metal rubber components, including the following steps:

[0081] S1. Generate the initial central trajectory path points of the laying process of metal rubber components;

[0082] Specifically, it includes the following steps:

[0083] S11. Set the initial parameters: For the nail plate as Figure 2 shown, it is necessary to set the number s of pins, the central coordinates C i (i = 1, 2,..., s) of the pins, the allowable laying radius r of the attached circle of the pins, the pin path w that the multi-layer laying trajectory needs to pass through, as Figure 2 shown by the thick solid line, the pin path of pin 1 - pin 2 - pin 4 - pin 5...、the interpolation spacing d, the vertical coordinate z0 in the vertical direction of the starting laying layer, the distance delta between every two laying layers, the vertical correction height h (h < delta), the number of laying layers i, and the vertical coordinate z i of each laying layer = z0 + delta × (i - 1), etc.;

[0084] S12. In the rectangular coordinate system, there are s pins in total, and the pin path is Generate the position of the initial central trajectory path points according to the pin path and the relative position of the positioning pins:

[0085] For the first segment of the path, that is segment: If pin a3 is above the line a1a2, then the corresponding trajectory takes the lower one of the two external common tangents of the attached circles ( Figure 3(a)) tangent point; if the pin a3 is below the straight line a1a2, the corresponding trajectory is the upper common tangent line of the two attached circles ( Figure 3 (b)) of the tangent point.

[0086] For the middle segment of the path, Segment, i=1,2,3,4,...,s-2:If a i-1 On the straight line a i a i+1 Below, a i+2 Above the straight line, the corresponding trajectory is Figure 3 (c) The points of tangency of the internal common tangents of the two subsidiary circles shown; if a i-1 On the straight line a i a i+1 Above, a i+2 Below the straight line, the corresponding trajectory is Figure 3 (d) The points of tangency of the internal common tangents of the two subsidiary circles shown; if a i-1 、a i+2 All in straight line a i a i+1 Below, the corresponding trajectory is the upper one of the external common tangent lines of the two attached circles ( Figure 3 (e)) tangent point; if a i-1 、a i+2 All in straight line a i a i+1 Above, the corresponding trajectory is the lower one of the two subordinate circles' external tangents ( Figure 3 (f)) of the tangent point.

[0087] For the end of the path, Section: If pin a s-2 On the straight line a s-1 a s Above, the corresponding trajectory is the lower one of the two external tangent lines of the attached circles ( Figure 3 (g)) tangency point; if the pin a s-2 On the straight line a s-1 a s Below, the corresponding trajectory is the upper common tangent line of the two attached circles ( Figure 3 (h)) tangent point;

[0088] S13, integrating all the above-mentioned tangent points to form an initial center trajectory path point;

[0089] S2, performing plane correction, vertical correction and smoothing processing on the path points of the initial center trajectory;

[0090] The specific steps include:

[0091] S21, plane correction;

[0092] If the initial track segment passes through some pin attached circles during the laying process, the corresponding track needs to be corrected in the plane. Figure 4 The method shown is to change the line segment to be corrected into a line segment-a minor arc-a line segment, and the radius of the minor arc is the same as the radius of the pin attachment circle;

[0093] S22, vertical correction;

[0094] During paving, the current track may cross or overlap with the previous track in the same paving layer. In this case, the vertical coordinates of the current track need to be changed. When the crossing or overlapping ends, the path returns to the paving layer. The vertical corrections required include the vertical corrections of the straight line segment and the vertical corrections of the arc segment.

[0095] For vertical correction of straight line segments, such as Figure 5 As shown in (a), the tracks intersect at point K. The current laying track needs to be corrected vertically. A circle is made with the track intersection point K as the center and the allowable laying radius r of the pin attachment circle as the radius. The intersection points of this circle with the current laying track are B' and C'. Another circle is made with 2r as the radius. The intersection points of this circle with the current laying track are A and D. Then the vertical coordinates of B' and C' are changed to z i =z0+delta×i-1)+h, and obtain B and C, and finally obtain the coordinates of the trajectory points A, B, C and D after vertical correction.

[0096] S23, smoothing processing;

[0097] For the non-guidable points (sharp points) formed by connecting straight lines and arcs at the plane correction and vertical correction in the initial trajectory, arc smoothing is needed to be used for transition removal; for the sharp points in the plane correction, plane arc transition is used; for the sharp points in the vertical correction, space arc transition is used.

[0098] Through Figure 6 The smoothing process shown in the figure solves the cusp problem, changes the path ADE into the path AMNE, and replaces the cusp D with the arc MN to ensure that the straight line segment and the arc segment can transition smoothly;

[0099] The specific method of plane arc transition is: take the pin C as the center of the circle and make a circle 1 with a radius of twice the allowable laying radius r of the pin attached circle, offset the line segment AD in the direction away from the center of the circle C by r to obtain the line segment A′D', the intersection point of the line segment A′D' and the circle 1 is P, project P to the line segment AD, the projection point is M, let the midpoint of PC be N, and finally obtain the coordinates of the trajectory points A, M, N and E after smoothing;

[0100] The specific method of spatial arc transition is: first, the path to be smoothed is transformed to the horizontal plane by using the Rodrigues rotation formula, then the plane arc transition is performed, and then the coordinates of the points after the plane arc transition are rotated back to the original plane by using the Rodrigues rotation formula;

[0101] S3, interpolating the corrected laying center trajectory path points to generate the center trajectory points of the metal rubber component;

[0102] The specific steps include:

[0103] S31. If a straight line segment is used to connect every two adjacent initial path points, the length of the line segment needs to be calculated, and then the number of interpolation points m2 is determined according to the required interpolation spacing d, and then the coordinates of each interpolation point are calculated by linear interpolation. The formula used is as follows:

[0104]

[0105] m1 is the number of linear interpolation points, x A ,y A are the x- and y-coordinates of the starting and ending points of the line segment. B ,y B are the x- and y-coordinates of the end points of the line segment, and d is the interpolation spacing.

[0106] S32. If an arc segment is used to connect every two adjacent initial path points, the length of the arc needs to be calculated, and then the number of interpolation points m2 is determined according to the required interpolation spacing d, and then the coordinates of each interpolation point are calculated by linear interpolation of the angle. The formula used is as follows:

[0107]

[0108] m2 is the number of arc interpolation points, α is the arc angle corresponding to the arc, r arc is the radius of the arc, and d is the interpolation spacing.

[0109] S33, integrating all interpolation points and initial path points to generate the center trajectory point of the paving path, see Figure 7 ;

[0110] S4, generating a spiral center trajectory of the metal rubber component according to the center trajectory point;

[0111] The specific steps include:

[0112] S41. In the global coordinate system, a cylindrical spiral is generated between every two center trajectory path points. The formula is as follows:

[0113]

[0114] Where θ=ωt, ω is the angular velocity, h is the pitch, β is the helix angle, the right helix takes a positive sign, and the left helix takes a negative sign.

[0115] S42, moving the cylindrical helix in the global coordinate system to the local coordinate system by translation and rotation (making the Z axis of the global coordinate system coincide with the Z axis of the local coordinate system);

[0116] Calculate the vectors between the two adjacent points of the interpolation point and set it as the Z-axis direction of the local coordinate system; calculate the rotation matrix R and translation matrix T between the Z-axes of the two coordinate systems, and the calculation formula for the coordinates of the points on the real spiral line is as follows:

[0117] The coordinates of a point on the real helix = T × R × the coordinates of a point on the cylindrical helix in the global coordinate system.

[0118] Rotation matrix R: calculated by Rodrigues rotation formula;

[0119] Translation matrix T: Where x, y and z are the coordinates of the interpolation point;

[0120] The final spiral path is shown in Figure 8 ;

[0121] S5. Around the central trajectory of the spiral, the spiral nodes and units are generated through an arithmetic progression, and then a grid is formed to complete the intelligent digital modeling of the metal rubber component laying process;

[0122] The specific steps include:

[0123] S51. Metal rubber is made of metal wire, and the cross section of the metal wire is circular. Therefore, the mesh division takes the central trajectory interpolation point as the center point, and generates the surrounding nodes (counterclockwise) around each center point through an arithmetic sequence, and then generates a unit. The nodes in the unit need to be sorted counterclockwise accordingly;

[0124] First, set the circular section radius r0, the number of nodes per circle on the circumference a, the number of grid division circles b, and the number of layers l (i.e. the number of center points).

[0125] The node coordinates of the center point are the coordinates of the center trajectory interpolation point. The node number of the center point uses the following formula:

[0126] n i =n1+(a×b+1)×(c i -1) (i=1,2,…,l)

[0127] Where n is the node number, a is the number of nodes on the circumference, b is the number of mesh divisions, and c is the number of nodes on the circumference. i is the i-th center point.

[0128] Then generate the coordinates and numbers of the remaining nodes around the central node. The coordinates of the remaining nodes are calculated using the following formula:

[0129]

[0130] Where x0, y0 and z0 are the coordinates of the center node, x, y and z are the coordinates of the nodes to be generated. is the radius of the i-th circle where the node is located, b is the number of grid division circles, and β=(j-1)θ is the circumferential angle corresponding to the j-th node.

[0131] The surface formed by each layer of nodes needs to be rotated accordingly around the corresponding center point.

[0132] The remaining nodes are numbered as follows:

[0133] For the nodes in the first circle of the first layer, the nodes in the horizontal direction are numbered 2, and the remaining nodes in the circle are sorted counterclockwise and numbered 3, 4, …, a+1; for the nodes in the kth circle of the first layer, the nodes in the horizontal direction are numbered 2+5×(k-1), and the remaining nodes in the circle are sorted counterclockwise and numbered 2+5×(k-1)+1, 2+5×(k-1)+2, …, 2+5×(k-1)+(a-1); and the same goes for the remaining circles.

[0134] S52, generate Fig. 9 The units and nodes shown in the figure include pentahedral units with a center point, a×(l-1) in total, and the rest are hexahedral units, a×(l-1)×(b-1) in total. The unit numbers are also generated in a counterclockwise manner. First, all pentahedral units are coded. The pentahedron composed of nodes 1-2-3-12-13-14 is unit 1, and the pentahedron composed of nodes 1-3-4-12-14-15 is unit 2, ..., counterclockwise, and so on; then all hexahedral units are coded. The hexahedron composed of nodes 2-7-8-3-13-18-19-14 is unit a×(l-1)+1, and the hexahedron composed of nodes 3-8-9-4-14-19-20-15 is unit a×(l-1)+2, ..., counterclockwise, and so on, until all units are coded.

[0135] S53, the grid is composed of six-node pentahedral elements and eight-node hexahedral elements. For the six-node pentahedral elements, the shape function adopts the following formula:

[0136]

[0137] For eight-node hexahedral elements, the shape function uses the following formula:

[0138]

[0139] In the formula, (ξ i ,η i ,ζ i ) represents the coordinates of node i of the unit in the (ξ,η,ζ) coordinate system.

[0140] like Fig.10 As shown in Figure 2, different numbers of elements and nodes can be generated for the model. The final metal rubber model is shown in Figure 2. Fig.11 , see the enlarged view of the local grid Fig.12 .

[0141] The present invention combines the finite element method with computer graphics theory to solve the related problems of intelligent digital modeling of the metal rubber component laying process, and can quickly realize the intelligent digital modeling of the metal rubber component laying process.

[0142] The above description does not limit the present invention in any form. Although the present invention has been disclosed by the above embodiments, it is not used to limit the present invention. Any technician familiar with the profession can make changes or modifications to equivalent embodiments of equivalent changes by using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An intelligent digital modeling method for the laying process of metal rubber components, characterized in that The following steps are involved: S1, generating the initial center trajectory path point of the metal rubber component laying process; S2, performing plane correction, vertical correction and smoothing processing on the path points of the initial center trajectory; S3, interpolating the corrected laying center trajectory path points to generate the center trajectory points of the metal rubber component; S4, generating a spiral center trajectory of the metal rubber component according to the center trajectory point; S5. Around the central trajectory of the spiral, the spiral nodes and units are generated through an arithmetic progression to form a grid, thus completing the intelligent digital modeling of the metal rubber component laying process.

2. According to claim 1, the intelligent digital modeling method for the laying process of metal rubber components is characterized in that The specific implementation method of step S1 is: S1, generating the initial center trajectory path point of the metal rubber component laying process; The specific steps include: S11. Set initial parameters: For the pegboard shown in Figure 2, it is necessary to set the number of pins s, the central coordinates of the pins C i (i = 1, 2,..., s), the allowable laying radius r of the pin附属圆 (it seems there is a wrong expression here, assuming it should be something like "the auxiliary circle of the pin"), the pin path w that the multi-layer laying trajectory needs to pass through. The pin path shown by the thick solid line in Figure 2 is pin 1 - pin 2 - pin 4 - pin 5... i The interpolation spacing d, the vertical coordinate z0 of the starting laying layer, the distance delta between every two laying layers, the height h of the vertical correction (h < delta), the number of laying layers i, and the vertical coordinate z of each laying layer = z0 + delta × (i - 1), etc.; It should be noted that there may be some inaccuracies in the original text, especially in the part of "销钉附属圆", which is not clearly expressed. The above translation is based on speculation to make the overall meaning as complete as possible. S12. In the rectangular coordinate system, there are s pins, and the pin path is a i+1 , the initial center trajectory path point position is generated according to the relative position of the pin path and the positioning pin: For the first segment of the path, Segment a2: If the pin a3 is above the straight line a1a2, the corresponding trajectory takes the tangency point of the lower common tangent line of the two attached circles (Figure 3(a)); if the pin a3 is below the straight line a1a2, the corresponding trajectory takes the tangency point of the upper common tangent line of the two attached circles (Figure 3(b)); For the middle segment of the path, a i+1 Segment, i=1,2,3,4,...,s-2:If a i-1 On the straight line a i a i+1 Below, a i+2 If a is above the straight line, the corresponding trajectory is the tangent point of the inner common tangent lines of the two attached circles shown in Figure 3(c); i-1 On the straight line a i a i+1 Above, a i+2 Below the straight line, the corresponding trajectory is the tangent point of the inner common tangent lines of the two attached circles shown in Figure 3(d); if a i-1 、a i+2 All in straight line a i a i+1 Below, the corresponding trajectory takes the tangent point of the upper common tangent line of the two attached circles (Figure 3(e)); if a i-1 、a i+2 All in straight line a i a i+1 Above, the corresponding trajectory takes the tangent point of the lower one of the external common tangent lines of the two attached circles (Figure 3(f)); For the end of the path, a s Section: If pin a s-2 On the straight line a s-1 a s Above, the corresponding trajectory takes the tangent point of the lower common tangent line of the two attached circles (Figure 3(g)); if pin a s-2 On the straight line a s-1 a s Below, the corresponding trajectory takes the tangent point of the upper common tangent line of the two subsidiary circles (Figure 3(h)); S13, integrating all the above-mentioned tangent points to form an initial center trajectory path point.

3. The intelligent digital modeling method for metal rubber component laying process according to claim 1 is characterized in that The specific implementation method of step S2 is: S21, plane correction; If the initial track segment passes through some pin attached circles during the laying process, the corresponding track needs to be corrected in the plane. By the method shown in FIG4 , the line segment to be corrected is changed into a line segment-a minor arc-a line segment. The radius of the minor arc is the same as the radius of the pin attached circle. S22, vertical correction; During paving, the current track may cross or overlap with the previous track in the same paving layer. In this case, the vertical coordinates of the current track need to be changed. When the crossing or overlapping ends, the path returns to the paving layer. The vertical corrections required include the vertical corrections of the straight line segment and the vertical corrections of the arc segment. For the vertical correction of the straight line segment, as shown in Figure 5(a), the tracks intersect at point K. The current laying track needs to be vertically corrected. A circle is made with the track intersection point K as the center and the allowable laying radius r of the pin attached circle as the radius. The intersection points of this circle with the current laying track are B′ and C′. Another circle is made with 2r as the radius. The intersection points of this circle with the current laying track are A and D. The vertical coordinates of B′ and C′ are then changed to z. i =z0+delta×(i-1)+h, get B and C, and finally get the coordinates of the vertically corrected trajectory points A, B, C and D; S23, smoothing processing; For the non-guidable points (cusps) formed by connecting straight lines and arcs at the plane correction and vertical correction in the initial trajectory, arc smoothing is required to remove them; for the sharp points in the plane correction, plane arc transition is adopted; for the sharp points in the vertical correction, space arc transition is adopted; The cusp problem is solved by smoothing as shown in FIG6 , changing the path ADE into the path AMNE, and replacing the cusp D with the arc MN to ensure smooth transition between the straight line segment and the arc segment; The specific method of plane arc transition is: take the pin C as the center of the circle and make a circle 1 with a radius of twice the allowable laying radius r of the pin attached circle, offset the line segment AD in the direction away from the center of the circle C by r to obtain the line segment A′D′, the intersection point of the line segment A′D′ and the circle 1 is P, project P onto the line segment AD, the projection point is M, let the midpoint of PC be N, and finally obtain the coordinates of the trajectory points A, M, N and E after smoothing; The specific method of spatial arc transition is: first, the path to be smoothed is transformed to the horizontal plane through the Rodrigues rotation formula, then the plane arc transition is performed, and then the point coordinates after the plane arc transition are rotated back to the original plane through the Rodrigues rotation formula.

4. The intelligent digital modeling method for metal rubber component laying process according to claim 1 is characterized in that The specific implementation method of step S3 is: S31. If a straight line segment is used to connect every two adjacent initial path points, the length of the line segment needs to be calculated, and then the number of interpolation points m2 is determined according to the required interpolation spacing d, and then the coordinates of each interpolation point are calculated by linear interpolation. The formula used is as follows: m1 is the number of linear interpolation points, x A ,y A are the x- and y-coordinates of the starting and ending points of the line segment. B ,y B are the x- and y-coordinates of the end points of the line segment, and d is the interpolation spacing; S32. If an arc segment is used to connect every two adjacent initial path points, the length of the arc needs to be calculated, and then the number of interpolation points m2 is determined according to the required interpolation spacing d, and then the coordinates of each interpolation point are calculated by linear interpolation of the angle. The formula used is as follows: m2 is the number of arc interpolation points, α is the arc angle corresponding to the arc, r arc is the radius of the arc, d is the interpolation spacing; S33, integrating all interpolation points and initial path points to generate the center trajectory point of the paving path, as shown in FIG7.

5. The intelligent digital modeling method for metal rubber component laying process according to claim 1 is characterized in that The specific implementation method of step S4 is: S41. In the global coordinate system, a cylindrical spiral is generated between every two center trajectory path points. The formula is as follows: In the formula, θ = ωωt, ω is the angular velocity, h is the pitch, β is the helix angle, the right helix takes a positive sign, and the left helix takes a negative sign; S42, moving the cylindrical helix in the global coordinate system to the local coordinate system by translation and rotation (making the Z axis of the global coordinate system coincide with the Z axis of the local coordinate system); Calculate the vectors between the two adjacent points of the interpolation point and set it as the Z-axis direction of the local coordinate system; calculate the rotation matrix R and translation matrix T between the Z-axes of the two coordinate systems, and the calculation formula for the coordinates of the points on the real spiral line is as follows: The coordinates of the point on the real helix = T × R × the coordinates of the point on the cylindrical helix in the global coordinate system; Rotation matrix R: calculated by Rodrigues rotation formula; Translation matrix T: Where x, y and z are the coordinates of the interpolation point; The final spiral path is shown in Figure 8.

6. The intelligent digital modeling method for metal rubber component laying process according to claim 1 is characterized in that The specific implementation method of step S5 is: S51. Metal rubber is made of metal wire, and the cross section of the metal wire is circular. Therefore, the mesh division takes the central trajectory interpolation point as the center point, and generates the surrounding nodes around each center point through an arithmetic sequence (sorted counterclockwise), and then generates a unit. The nodes in the unit need to be sorted counterclockwise accordingly. First, set the circular section radius r0, the number of nodes per circle on the circumference a, the number of mesh division circles b, and the number of layers l (i.e., the number of center points); The node coordinates of the center point are the coordinates of the center trajectory interpolation point. The node number of the center point uses the following formula: n i =n1+(a×b+1)×(c i -1) (i=1,2,...,l) Where n is the node number, a is the number of nodes on the circumference, b is the number of mesh divisions, and c is the number of nodes on the circumference. i is the i-th center point; Then generate the coordinates and numbers of the remaining nodes around the central node. The coordinates of the remaining nodes are calculated using the following formula: Where x0, y0 and z0 are the coordinates of the center node, x, y and z are the coordinates of the nodes to be generated. is the radius of the i-th circle where the node is located, b is the number of mesh division circles, β = (j-1)θ is the circumferential angle corresponding to the j-th node; The surface formed by each layer of nodes needs to be rotated around the corresponding center point; The remaining nodes are numbered as follows: For the nodes of the first circle of the first layer, let the horizontal node number be 2, and the remaining nodes of the circle are sorted counterclockwise, and are numbered 3, 4, ..., a+1; for the nodes of the kth circle of the first layer, let the horizontal node number be 2+5×(k-1), and the remaining nodes of the circle are sorted counterclockwise, and are numbered 2+5×(k-1)+1, 2+5×(k-1)+2, ..., 2+5×(k-1)+(a-1); and the rest of the circles are numbered in the same way; S52, generate units and nodes as shown in FIG9 , wherein the unit containing the center point is a pentahedral unit, a×(l-1) in total, and the rest are hexahedral units, a×(l-1)×(b-1) in total, and the unit numbers are also generated in a counterclockwise manner, firstly, all pentahedral units are encoded, the pentahedron composed of nodes 1-2-3-12-13-14 is unit 1, the pentahedron composed of nodes 1-3-4-12-14-15 is unit 2, ..., counterclockwise and so on; then, all hexahedral units are encoded, the hexahedron composed of nodes 2-7-8-3-13-18-19-14 is unit a×(l-1)+1, the hexahedron composed of nodes 3-8-9-4-14-19-20-15 is unit a×(l-1)+2, ..., counterclockwise and so on, until all units are encoded; S53, the grid is composed of six-node pentahedral elements and eight-node hexahedral elements. For the six-node pentahedral elements, the shape function adopts the following formula: For eight-node hexahedral elements, the shape function uses the following formula: In the formula, (ξ i , η i , ζi) represents the coordinates of node i of the unit in the (ξ, η, ζ) coordinate system; As shown in FIG. 10 , different numbers of units and nodes can be generated for the model. The final metal rubber model is shown in FIG. 11 , and the local mesh enlargement is shown in FIG. 12 .

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