Field quantity updating method for numerical manifold simulation of metal plastic deformation

Abstract

This invention relates to the technical field of metal plastic deformation simulation calculation, and proposes a field quantity update method for numerical manifold simulation calculation of metal plastic deformation, comprising the following steps: acquiring the node information of the mathematical mesh used for metal plastic deformation simulation calculation, the mesh information of the manifold element at the previous time step during the metal plastic deformation process, and the mesh information of the manifold element before the current time step update; using the acquired information to determine the manifold element number of the point P located at the node position of the mathematical mesh at the current time step at the previous time step, thereby obtaining the element information; using the element information to calculate the coordinates of point P at the previous time step; and using the acquired information to calculate the point P located at the fixed boundary position of the physical geometry of the deformable body at the current time step. g and point P located at the free boundary of the deformable body's physical geometry. z Find the coordinates of the previous time step; calculate point P and point P' at the previous time step. g and point P z The velocity field quantity is obtained, and the field quantity of the manifold element is updated using the obtained velocity field quantity.

Description

Technical Field

[0001] This invention relates to the technical field of simulation calculation of metal plastic deformation, and more specifically, to a field quantity update method for numerical manifold simulation calculation of metal plastic deformation. Background Technology

[0002] Metal plastic forming is a fundamental metal processing technology widely used in various fields of manufacturing. Currently, the plastic finite element method (FEM) is the main numerical method used in computer simulation of metal plastic deformation during the forming process. The FEM method introduces a finite element mesh to simulate the geometry, structure, and mechanical behavior of the metal. It utilizes the computer to update the field quantities on the finite element mesh at each time step of the metal plastic deformation process to simulate the behavior during deformation. Among the finite element mesh field quantities that need to be updated is the velocity field, which is crucial. The velocity field allows for the calculation of the stress and strain states of the metal, which are key indicators of metal plastic deformation and have a significant impact on the accuracy of the numerical simulation results.

[0003] In the simulation of metal plastic deformation, the geometry of the metal changes as deformation progresses. Using the plastic finite element method (FEM) for simulation calculations leads to distortion of the finite element mesh. It is necessary to use mesh re-meshing methods to adjust the shape and density of the finite element mesh elements to adapt to the deformed geometry. Moreover, the parameters of the finite element mesh need to be updated synchronously, resulting in low computational efficiency and accuracy of the plastic finite element method in simulating large metal deformation. Furthermore, since the computational accuracy of the plastic finite element method is only related to the time step and the shape and size of the element mesh, the only way to improve the computational accuracy of the plastic finite element method is to refine the mesh. However, refining the mesh increases the workload of mesh generation during the simulation process, thereby reducing the computational efficiency of the plastic finite element method.

[0004] To overcome the limitations of the plastic finite element method, existing technologies propose a numerical manifold simulation method for metal forming processes. This method introduces the numerical manifold method into the field of metal deformation simulation and establishes a numerical manifold analysis system for metal deformation processes.

[0005] The numerical manifold method, proposed by Shi Genhua in 1991, is based on the theory of finite covers associated with a freely moving interface and a fixed mathematical mesh. It employs a finite element cover system for numerical computation. This system has two separate and independent meshes: a mathematical mesh and a physical mesh. Both the mathematical and physical meshes require unit decomposition and transformation into mathematical and physical covers. The shape of the mathematical cover is unrestricted, while the shape of the physical cover is determined by the physical and geometric properties of the material. The common region or intersection of all physical covers is called a manifold element.

[0006] Numerical manifold methods utilize the theory of finite coverings, which associate free-moving interfaces with fixed mathematical meshes, to track the positional changes of the covering midpoint on the mathematical mesh at each time step, thereby updating the finite covering system. The fixed mathematical mesh of the finite element covering system simplifies mesh generation and avoids mesh distortion, making it well-suited for physical problems with rapidly changing field variables. This gives numerical manifold methods excellent adaptability to numerical simulation analysis of metal plastic deformation problems characterized by large displacements, large deformations, and material damage, addressing the issues of mesh distortion, computational efficiency, and handling of moving interfaces present in current plastic finite element and finite volume methods. Because numerical manifold methods use finite covering techniques based on mathematical and physical meshes for computation, the physical mesh changes at each time step during deformation, while the mathematical mesh remains constant. Therefore, updating the mathematical mesh by updating the finite covering system is necessary to ensure that the updated mathematical mesh is correlated with the changing physical mesh.

[0007] In existing methods, a mesh repartitioning technique is used to update a finite coverage system by re-dividing the elongated or defective mathematical mesh. However, this mesh repartitioning technique causes some nodes of the mathematical mesh to malfunction, resulting in low computational accuracy. Moreover, this mesh repartitioning technique is computationally difficult and is hard to implement in practice using programming. In numerical manifold simulation of metal plastic deformation, a time-stepping method is required to simulate the time evolution during the metal plastic deformation process. If this mesh repartitioning technique is represented in a programmatic way, the elongated or defective mathematical mesh must be re-divided in each time step. This means that a mesh repartitioning calculation must be performed in each time step, which requires a large amount of computation, resulting in long processing time and low computational efficiency when obtaining the results of the numerical simulation of plastic forming.

[0008] In summary, the methods proposed in the existing technology for numerical simulation calculations of plastic forming have the drawbacks of low computational accuracy and efficiency. Summary of the Invention

[0009] To overcome the shortcomings of low computational accuracy and efficiency in the prior art, this invention provides a field quantity update method for numerical manifold simulation of metal plastic deformation that can improve computational efficiency and accuracy.

[0010] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0011] A method for updating field quantities in numerical manifold simulation of plastic deformation of metals includes the following steps:

[0012] S1: Obtain the node information of the mathematical mesh used for the simulation calculation of metal plastic deformation, the mesh information of the manifold element at the previous time step during the metal plastic deformation process, and the mesh information of the manifold element before the current time step update.

[0013] S2: Using the node information of the mathematical grid and the grid information of the manifold cell in the previous time step, determine several manifold cells adjacent to the mathematical grid node, and use the several manifold cells adjacent to the mathematical grid node to determine the manifold cell number of the point P located at the mathematical grid node position in the previous time step, thus obtaining the cell information.

[0014] S3: Using the cell information, the coordinates of point P in the manifold cell are represented by the coordinate interpolation of the nodes of the manifold cell at the current time, and the coordinate interpolation relationship between point P and the nodes of the manifold cell is obtained.

[0015] S4: Using the coordinate interpolation relationship between point P and the nodes of the manifold element in which it is located, and the node coordinates of the manifold element at the previous time step, calculate the coordinates of point P at the previous time step.

[0016] S5: Using the mesh information of the manifold element from the previous time step and the mesh information of the manifold element before the current time step update, calculate the point P located at the fixed boundary position of the deformable body's physical geometry at the current time step. g and point P located at the free boundary of the deformable body's physical geometry. z The coordinates at the previous moment;

[0017] S6: Based on point P, point P g and point P z Given the coordinates of the previous moment, calculate the points P and P' of the previous moment. g and point P z The velocity field quantity is obtained, and the field quantity of the manifold element is updated using the obtained velocity field quantity to obtain the mesh information and field quantity information of the updated manifold element.

[0018] This invention also proposes a field quantity update system for numerical manifold simulation of metal plastic deformation to implement the above-mentioned field quantity update method for numerical manifold simulation of metal plastic deformation, including:

[0019] The data acquisition module is used to acquire the node information of the mathematical mesh used for the simulation calculation of metal plastic deformation, the mesh information of the manifold element at the previous moment during the metal plastic deformation process, and the mesh information of the manifold element before the current moment update.

[0020] The cell information calculation module is used to determine several manifold cells adjacent to the mathematical grid nodes using the node information of the mathematical grid and the grid information of the manifold cells at the previous time step, and to determine the manifold cell number of the point P located at the mathematical grid node position at the current time step at the previous time step using the several manifold cells adjacent to the mathematical grid nodes, thus obtaining cell information.

[0021] The coordinate interpolation calculation module is used to use cell information to represent the coordinates of point P in the manifold cell by interpolating the coordinates of the nodes of the manifold cell at the current time, and to obtain the coordinate interpolation relationship between point P and the nodes of the manifold cell.

[0022] The first coordinate calculation module is used to calculate the coordinates of point P at the previous moment by using the coordinate interpolation relationship between point P and the nodes of the manifold unit and the node coordinates of the manifold unit at the previous moment.

[0023] The second coordinate calculation module is used to calculate the point P located at the fixed boundary position of the deformable body's physical geometry at the current moment, using the mesh information of the manifold element at the previous time step and the mesh information of the manifold element before the current time step's update. g and point P located at the free boundary of the deformable body's physical geometry. z The coordinates at the previous moment;

[0024] The field quantity update module is used to update the field quantity based on point P and point P. g and point P z Given the coordinates of the previous moment, calculate the points P and P' of the previous moment. g and point P z The velocity field quantity is obtained, and the field quantity of the manifold element is updated using the obtained velocity field quantity to obtain the mesh information and field quantity information of the updated manifold element.

[0025] The present invention also proposes a computer device, including a memory and a processor, wherein the memory stores computer-readable instructions, wherein when the computer-readable instructions are executed by the processor, the processor causes the processor to perform the steps of the field quantity update method for numerical manifold simulation calculation of metal plastic deformation proposed in the present invention.

[0026] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0027] This invention utilizes the node information of a mathematical mesh, the mesh information of the manifold element at the previous moment during the plastic deformation of metal, and the mesh information of the manifold element before the current moment update to calculate the velocity field. The calculated velocity field is then used to update the field of the manifold element, resulting in the updated mesh information and field information of the manifold element. This method eliminates the need to re-divide the mathematical mesh, requires minimal computation, and ensures that all nodes of the mathematical mesh can operate normally, thereby improving the computational efficiency and accuracy of numerical simulation of plastic forming. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating the field quantity update method for numerical manifold simulation calculation of metal plastic deformation proposed in Example 1.

[0029] Figure 2 This is a schematic diagram of the roughing deformation process of the metal uproot as proposed in Example 1;

[0030] Figure 3 This is a schematic diagram of the coverage system proposed in Example 1;

[0031] Figure 4 This is a schematic diagram of the displacement changes of the manifold element nodes proposed in Example 1;

[0032] Figure 5 This is a schematic diagram of the mesh before and after the manifold unit update proposed in Example 1;

[0033] Figure 6 This is a schematic diagram of the node states of the manifold unit before and after deformation as proposed in Example 1;

[0034] Figure 7 This is an overall framework diagram of the field quantity update system for numerical manifold simulation calculation of metal plastic deformation proposed in Example 2. Detailed Implementation

[0035] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0036] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions;

[0037] It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings.

[0038] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] Example 1

[0040] This embodiment proposes a field quantity update method for numerical manifold simulation calculation of metal plastic deformation. Figure 1 This is a flowchart illustrating the field quantity update method for numerical manifold simulation calculation of metal plastic deformation in this embodiment.

[0041] The field quantity update method for numerical manifold simulation of metal plastic deformation proposed in this embodiment includes the following steps:

[0042] S1: Obtain the node information of the mathematical mesh used for the simulation calculation of metal plastic deformation, the mesh information of the manifold element at the previous time step during the metal plastic deformation process, and the mesh information of the manifold element before the current time step update.

[0043] S2: Using the node information of the mathematical grid and the grid information of the manifold cell in the previous time step, determine several manifold cells adjacent to the mathematical grid node, and use the several manifold cells adjacent to the mathematical grid node to determine the manifold cell number of the point P located at the mathematical grid node position in the previous time step, thus obtaining the cell information.

[0044] S3: Using the cell information, the coordinates of point P in the manifold cell are represented by the coordinate interpolation of the nodes of the manifold cell at the current time, and the coordinate interpolation relationship between point P and the nodes of the manifold cell is obtained.

[0045] S4: Using the coordinate interpolation relationship between point P and the nodes of the manifold element in which it is located, and the node coordinates of the manifold element at the previous time step, calculate the coordinates of point P at the previous time step.

[0046] S5: Using the mesh information of the manifold element from the previous time step and the mesh information of the manifold element before the current time step update, calculate the point P located at the fixed boundary position of the deformable body's physical geometry at the current time step. g and point P located at the free boundary of the deformable body's physical geometry. z The coordinates at the previous moment;

[0047] S6: Based on point P, point P g and point P z Given the coordinates of the previous moment, calculate the points P and P' of the previous moment. g and point P z The velocity field quantity is obtained, and the field quantity of the manifold element is updated using the obtained velocity field quantity to obtain the mesh information and field quantity information of the updated manifold element.

[0048] In the specific implementation process, the velocity field is calculated by using the node information of the mathematical grid, the grid information of the manifold element at the previous moment during the plastic deformation of the metal, and the grid information of the manifold element before the current moment update. The calculated velocity field is then used to update the field of the manifold element, resulting in the updated grid information and field information of the manifold element. This eliminates the need to re-divide the mathematical grid, requires less computation, and ensures that all nodes of the mathematical grid can operate normally, thereby improving the computational efficiency and accuracy of the numerical simulation of plastic forming.

[0049] As an example, point P represents any point located within the physical geometric boundary of the mathematical grid at the current moment; point P g Point P represents any point located at a fixed boundary position in the physical geometry of the deformable body at the current moment; z This represents any point located at the free boundary of the deformable body's physical geometry at the current moment;

[0050] As an example, Figure 2 The diagram shows the deformation process of the metal pier. The area enclosed by the solid line is the physical geometry of the metal pier. Now, a rectangular mathematical grid is established that is independent of the structure of the metal pier but must cover the entire solution domain, i.e., mathematical coverage. Each intersection of the mathematical grid is the center point of the corresponding mathematical coverage, called a node, and is denoted as (1), (2)...(16). The area of ​​each mathematical coverage is all the basic rectangular areas that contain this node. As an example, mathematical coverage (5) is a rectangular area enclosed by (1)(2)(6)(10)(9)(5)(1), and mathematical coverage (6) is composed of rectangular areas enclosed by (1)(2)(3)(7)(11)(10)(9)(5)(1).

[0051] The intersection of the physical structure and the mathematical cover forms a physical cover system over the solution domain, and the common region or intersection of each physical cover is a manifold element; as an example, for a rectangular mesh, a 4-node manifold element is the common region of 4 physical covers.

[0052] Figure 3 This is a schematic diagram of the coverage system; Figure 3 The four-node manifold elements in the model include 1, 5, 6, 2, 2, 6, 7, 3, 3, 7, 8, 4, etc. Each four-node manifold element has four physical covers, and adjacent manifold elements share the same cover nodes along a common boundary. During the plastic deformation of the metal, the nodes of the originally divided manifold elements will shift and change with the plastic deformation of the metal. Figure 4 This is a schematic diagram of the displacement changes of the nodes in the manifold element. Figure 4 In the middle, at the previous moment t n The partitioned manifold units at the current time t n+1Deformation occurs, and some manifold element nodes are no longer applicable at the current time t. n+1 The simulation calculation requires grid updates and field transformations to determine the current time t. n+1 The simulation calculations require mesh updates and field transformations at every moment during the metal's plastic deformation process until the metal reaches the deformation requirements and the plastic deformation ends.

[0053] Figure 5 This is a schematic diagram of the mesh before and after the manifold element update. Figure 5 It shows the current time t n+1 The corresponding mesh diagram before the manifold unit update, and the current time t. n+1 The corresponding updated mesh diagram of the manifold unit.

[0054] In an optional embodiment, point P is located at grid node J of the mathematical grid at the current moment, and point P was located inside or at the boundary of a four-node rectangular manifold cell klmn at the previous moment, where k, l, m and n are all nodes of the rectangular manifold cell klmn; using the coordinates of point P, the number of the manifold cell where point P was located at the current moment at the previous moment is determined, and cell information is obtained.

[0055] The steps for obtaining unit information include:

[0056] S2.1: Let node k of manifold element klmn coincide with node J of mathematical grid;

[0057] S2.2: If vector or If point P at the current moment is located at the boundary of manifold element klmn, the element information is obtained, and the process proceeds to step S3; otherwise, the process proceeds to step S2.3.

[0058] S2.3: If vector If all values ​​are positive or all values ​​are negative, then point P at the current moment is determined to be inside manifold unit klmn, and the unit information is obtained, proceeding to step S3; otherwise, point P at the current moment is determined to be outside manifold unit klmn.

[0059] S2.4: Let node l of manifold element klmn coincide with node J of mathematical grid, and repeat steps S2.2 to S2.3. If element information is obtained, proceed to step S3; otherwise, execute step S2.5.

[0060] S2.5: Let node m of manifold element klmn coincide with node J of mathematical grid, and repeat steps S2.2 to S2.3. If element information is obtained, proceed to step S3; otherwise, execute step S2.6.

[0061] S2.6: Let node m of manifold element klmn coincide with node J of mathematical grid, repeat steps S2.2 to S2.3, and then execute step S3;

[0062] As an example, at the previous time t n With the current time t n+1 The interval between them is a preset value. Because this preset value is small, the displacement of the manifold element nodes is also small. Therefore, at the previous time t... n A point located within a manifold cell at the current time t n+1 The manifold element remains within the manifold element before deformation;

[0063] by Figure 4 Taking node (6) as an example, at the previous time t n The manifold elements adjacent to node (6) are manifold elements 6,10,11,17, 2,6,7,3, 1,5,6,2 and 5,9,10,6. If at the current time t n+1 Point P arrives at node (6), in order to track point P at the previous time t n Let the node numbers of manifold elements 6, 10, 11, and 17 be k, l, m, and n respectively, arranged counterclockwise. Then, by comparing the coordinates of point P with those of node klmn in manifold element t at the current time... n+1 The coordinates of point P can be used to obtain the vectors between point P and nodes k, l, m, n respectively. The sign of the cross product of these vectors can be used to determine whether point P is inside or on the boundary of manifold element klmn. If the result is that point P is not inside or on the boundary of manifold element klmn, then the node numbers of manifold elements 2, 6, 7, 3 are set to k, l, m, n respectively in a counterclockwise direction, and the judgment is repeated. If the result is that point P is not inside or on the boundary of manifold element klmn, then the node numbers of manifold elements 1, 5, 6, 2 are set to k, l, m, n respectively in a counterclockwise direction, and the judgment is repeated. If the result is that point P is not inside or on the boundary of manifold element klmn, then the node numbers of manifold elements 5, 9, 10, 6 are set to k, l, m, n respectively in a counterclockwise direction, and the judgment is repeated.

[0064] In an optional embodiment, the expression for the coordinate interpolation relationship between point P and the node of its manifold element is:

[0065]

[0066]

[0067] In the formula, x j The x-coordinate of point P at the current moment is represented by y. j This represents the ordinate value of point P at the current moment, x. kLet x represent the coordinates of node k in manifold element klmn at the current time. l Let x represent the coordinates of node l of manifold element klmn at the current time. m Let x represent the coordinates of node m of manifold element klmn at the current time. n Represents the coordinates of node n of manifold element klmn at the current time;

[0068] As an example, Figure 6 This is a schematic diagram of the nodal states of the manifold element before and after deformation. Figure 4 Taking a node (6) of a mathematical grid as an example, Figure 6 Showing Figure 4 Node (6) and manifold elements 2, 6, 7, 3 at the previous time t n up to the current time t n+1 Positional relationship, Figure 6 k'l'm'n' represents the state of manifold element 2673 before deformation. Figure 6 Let klmn be the deformed state; let point P be at the current time t. n+1 Reaching the mathematical grid node (6) Figure 6 The position of node l' in the middle is determined by point P at the current time t. n+1 After the mesh deformation, the element is 2, 6, 7, 3, meaning the nodes of the manifold element klmn are in the order 2, 6, 7, 3. Therefore, at the current time t... n+1 The node coordinates of manifold element klmn and the current time t n+1 The position of point P, i.e., the coordinates of point l', allows us to determine the coordinates of point P before the deformation of the manifold element; because at the current time t... n+1 The manifold element klmn is an irregular quadrilateral. To find the coordinates of point P, we need the coordinates at the current time t. n+1 The deformed irregular quadrilateral manifold element is mapped to a square with a side length of 2. Specifically, a local reference coordinate system Oξη is established, thereby mapping the current time t... n+1 The deformed irregular quadrilateral manifold element is mapped to a square with a side length of 2. Any point (ξ, η) in the mapped manifold element klmn is analogous to a point (x, η) in the original manifold element klmn. j ,y j There is a one-to-one correspondence, although they are in two different coordinate systems, but the point (x) j ,y j The interpolation relationship between the nodes k, l, m, n in the original coordinate system and the mapped nodes is consistent with the interpolation relationship between the point (ξ, η) corresponding to the point (x, y) in the reference coordinate system Oξη. We can use this property of invariant interpolation relationship to calculate the coordinates (ξ, η) of the mapped point P.

[0069] exist Figure 4 Let point P be at the current time t. n+1 The coordinates are (x j ,y j If point P is a point within a manifold element klmn containing point P, then the interpolation relationship between the coordinates of point P and the four nodes of that manifold is:

[0070] Where c∈k,l,m,n(1)

[0071] The displacement function expression for the manifold element klmn is:

[0072]

[0073] Combining equations (1) and (2), we obtain the following linear equation in two variables:

[0074]

[0075]

[0076] Solving this linear equation in two variables will yield the coordinates (ξ, η).

[0077] In an optional embodiment, the expression for calculating the coordinates (x', y') of point P at the previous moment is:

[0078]

[0079]

[0080] In the formula, x k 'Represents the coordinates of node k in manifold element klmn at the previous time step, x' l ' represents the coordinates of node l of manifold element klmn at the previous time step, x m 'Represents the coordinates of node m of manifold element klmn at the previous time step, x' n ' represents the coordinates of node n of manifold element klmn at the previous time step.

[0081] In an alternative embodiment, point P g (x g The coordinates (x, 0) at the previous time step. g The expression for calculating ',0) is:

[0082]

[0083]

[0084]

[0085] x g =N1x1'+N2x2'

[0086] x1≤x g ≤x2

[0087] In the formula, x1 represents the current time relative to P. g The x-coordinate of an adjacent boundary node, x2, represents the distance between the current time and P. g The x-coordinate of the adjacent boundary node, x1' represents the coordinate of x1 at the previous time, and x2' represents the coordinate of x2 at the previous time;

[0088] As an example, the velocity of a point on a fixed boundary in the horizontal or vertical direction is zero or a fixed value. This optional embodiment provides a point P where the calculated vertical coordinate value is zero. g (x g The method for calculating the coordinates of a point P at the previous time step (0) is also applicable to calculating the coordinates of a point P with a x-coordinate of zero. g (x g The coordinates of ,0) at the previous time step.

[0089] In an alternative embodiment, point P z (x z ,y z The coordinates (x, y) at the previous time step z ',y z The calculation expression for ') is:

[0090]

[0091]

[0092]

[0093] x z =N3x3'+N4x4'

[0094]

[0095] x3≤x z ≤x4 or y3≤y z ≤y4

[0096] In the formula, the point with coordinates (x3, y3) and the point with coordinates (x4, y4) at the current time are related to point P. z (x z ,y z (x3',y3') represents the coordinates of the point with coordinates (x3,y3) at the previous moment, and (x4',y4') represents the coordinates of the point with coordinates (x4,y4) at the previous moment.

[0097] As an example, the velocity of a point on the free boundary in the horizontal or vertical direction is not zero and is not a fixed value.

[0098] In an alternative embodiment, based on point P, point P g and point P z Given the coordinates of the previous moment, calculate the points P and P' of the previous moment. g and point P z The expression for calculating the velocity field under constant coverage is:

[0099]

[0100]

[0101]

[0102] In the formula, (x,y) represents point P and point P' at the previous time step. g Or point P z The coordinates are given by: u represents the velocity of the point at coordinate (x, y) along the horizontal axis, v represents the velocity of the point at coordinate (x, y) along the vertical axis; (x0, y0) represents the center coordinates of the manifold cell containing the point at coordinate (x, y); a and b represent the length and width of the manifold cell containing the point at coordinate (x, y), respectively. i and v i d1 and d2 represent the velocities of the i-th node in the manifold cell containing the point with coordinates (x, y) in the horizontal and vertical directions, respectively; d1 and d2 represent the coverage coefficients of the constant cover; and e represents the manifold cell corresponding to the point with coordinates (x, y).

[0103] In an alternative embodiment, based on point P, point P g and point P z Given the coordinates of the previous moment, calculate the points P and P' of the previous moment. g and point P z The expression for calculating the velocity field under linear coverage is:

[0104]

[0105]

[0106]

[0107] In the formula, (x,y) represents point P and point P' at the previous time step. g Or point P zThe coordinates are given by: u represents the velocity of the point at coordinate (x, y) along the horizontal axis, v represents the velocity of the point at coordinate (x, y) along the vertical axis; (x0, y0) represents the center coordinates of the manifold cell containing the point at coordinate (x, y); a and b represent the length and width of the manifold cell containing the point at coordinate (x, y), respectively. i and v i These represent the i-th node (x, y) of the manifold unit containing the point with coordinates (x, y). i ,y i ) the velocity in the horizontal direction and the velocity in the vertical direction; d3~d8 represent the coverage coefficients of the linear cover with the cover formula [1 xy], and e represents the manifold element corresponding to the point with coordinates (x,y).

[0108] Example 2

[0109] This embodiment proposes a field quantity update system for numerical manifold simulation of metal plastic deformation, which is used to implement the field quantity update method for numerical manifold simulation of metal plastic deformation proposed in Embodiment 1.

[0110] Figure 7 This is an overall framework diagram of the field quantity update system for numerical manifold simulation calculation of metal plastic deformation in this embodiment.

[0111] The field quantity update system for numerical manifold simulation of metal plastic deformation includes:

[0112] The data acquisition module is used to acquire the node information of the mathematical mesh used for the simulation calculation of metal plastic deformation, the mesh information of the manifold element at the previous moment during the metal plastic deformation process, and the mesh information of the manifold element before the current moment update.

[0113] The cell information calculation module is used to determine several manifold cells adjacent to the mathematical grid nodes using the node information of the mathematical grid and the grid information of the manifold cells at the previous time step, and to determine the manifold cell number of the point P located at the mathematical grid node position at the current time step at the previous time step using the several manifold cells adjacent to the mathematical grid nodes, thus obtaining cell information.

[0114] The coordinate interpolation calculation module is used to use cell information to represent the coordinates of point P in the manifold cell by interpolating the coordinates of the nodes of the manifold cell at the current time, and to obtain the coordinate interpolation relationship between point P and the nodes of the manifold cell.

[0115] The first coordinate calculation module is used to calculate the coordinates of point P at the previous moment by using the coordinate interpolation relationship between point P and the nodes of the manifold unit and the node coordinates of the manifold unit at the previous moment.

[0116] The second coordinate calculation module is used to calculate the point P located at the fixed boundary position of the deformable body's physical geometry at the current moment, using the mesh information of the manifold element at the previous time step and the mesh information of the manifold element before the current time step's update. g and point P located at the free boundary of the deformable body's physical geometry. z The coordinates at the previous moment;

[0117] The field quantity update module is used to update the field quantity based on point P and point P. g and point P z Given the coordinates of the previous moment, calculate the points P and P' of the previous moment. g and point P z The velocity field quantity is obtained, and the field quantity of the manifold element is updated using the obtained velocity field quantity to obtain the mesh information and field quantity information of the updated manifold element.

[0118] It is understood that the system in this embodiment is applied to the method in Embodiment 1 above, and the options in Embodiment 1 above are also applicable to this embodiment, so they will not be described again here.

[0119] Example 3

[0120] This embodiment proposes a computer device, including a memory and a processor. The memory stores computer-readable instructions, wherein when the computer-readable instructions are executed by the processor, the processor performs the steps of the field quantity update method for numerical manifold simulation calculation of metal plastic deformation proposed in Embodiment 1.

[0121] It is understood that the computer device in this embodiment is applied to the method in Embodiment 1 above, and the options in Embodiment 1 above are also applicable to this embodiment, so they will not be described again here.

[0122] The same or similar labels correspond to the same or similar parts;

[0123] The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0124] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for updating field quantities in numerical manifold simulation of plastic deformation of metals, characterized in that, Includes the following steps: S1: Obtain the node information of the mathematical mesh used for the simulation calculation of metal plastic deformation, the mesh information of the manifold element at the previous time step during the metal plastic deformation process, and the mesh information of the manifold element before the current time step update. S2: Using the node information of the mathematical grid and the grid information of the manifold cell in the previous time step, determine several manifold cells adjacent to the mathematical grid node, and use the several manifold cells adjacent to the mathematical grid node to determine the manifold cell number of the point P located at the mathematical grid node position in the previous time step, thus obtaining the cell information. S3: Using the cell information, the coordinates of point P in the manifold cell are represented by the coordinate interpolation of the nodes of the manifold cell at the current time, and the coordinate interpolation relationship between point P and the nodes of the manifold cell is obtained. S4: Using the coordinate interpolation relationship between point P and the nodes of the manifold element in which it is located, and the node coordinates of the manifold element at the previous time step, calculate the coordinates of point P at the previous time step. S5: Using the mesh information of the manifold element from the previous time step and the mesh information of the manifold element before the current time step update, calculate the point P located at the fixed boundary position of the deformable body's physical geometry at the current time step. g and point P located at the free boundary of the deformable body's physical geometry. z The coordinates at the previous moment; S6: Based on point P, point P g and point P z Given the coordinates of the previous moment, calculate the points P and P' of the previous moment. g and point P z The velocity field quantity is obtained, and the field quantity of the manifold element is updated using the obtained velocity field quantity to obtain the mesh information and field quantity information of the updated manifold element.

2. The field quantity update method for numerical manifold simulation calculation of metal plastic deformation according to claim 1, characterized in that, Let point P be located at grid node J of the mathematical grid at the current moment, and let point P be located inside or at the boundary of a four-node rectangular manifold element klmn at the previous moment, where k, l, m and n are all nodes of the rectangular manifold element klmn; using the coordinates of point P, determine the number of the manifold element where point P was located at the current moment at the previous moment, and obtain the element information. The steps for obtaining unit information include: S2.1: Let node k of manifold element klmn coincide with node J of mathematical grid; S2.2: If vector or If point P at the current moment is located at the boundary of manifold element klmn, the element information is obtained, and the process proceeds to step S3; otherwise, the process proceeds to step S2.

3. S2.3: If vector and If all values ​​are positive or all values ​​are negative, then point P at the current moment is determined to be inside manifold unit klmn, and the unit information is obtained, proceeding to step S3; otherwise, point P at the current moment is determined to be outside manifold unit klmn. S2.4: Let node l of manifold element klmn coincide with node J of mathematical grid, and repeat steps S2.2 to S2.

3. If element information is obtained, proceed to step S3; otherwise, execute step S2.

5. S2.5: Let node m of manifold element klmn coincide with node J of mathematical grid, and repeat steps S2.2 to S2.

3. If element information is obtained, proceed to step S3; otherwise, execute step S2.

6. S2.6: Let node n of manifold element klmn coincide with node J of mathematical grid, repeat steps S2.2 to S2.3, and then execute step S3.

3. The field quantity update method for numerical manifold simulation calculation of metal plastic deformation according to claim 2, characterized in that, The expression for the coordinate interpolation relationship between point P and the nodes of the manifold element is: In the formula, x j The x-coordinate of point P at the current moment is represented by y. j This represents the ordinate value of point P at the current moment, x. k Let x represent the coordinates of node k in manifold element klmn at the current time. l Let x represent the coordinates of node l of manifold element klmn at the current time. m Let x represent the coordinates of node m of manifold element klmn at the current time. n This represents the coordinates of node n of manifold element klmn at the current time.

4. The field quantity update method for numerical manifold simulation calculation of metal plastic deformation according to claim 3, characterized in that, The expression for calculating the coordinates (x', y') of point P at the previous moment is: In the formula, x k 'Represents the coordinates of node k in manifold element klmn at the previous time step, x' l ' represents the coordinates of node l of manifold element klmn at the previous time step, x m 'Represents the coordinates of node m of manifold element klmn at the previous time step, x' n ' represents the coordinates of node n of manifold element klmn at the previous time step.

5. The field quantity update method for numerical manifold simulation calculation of metal plastic deformation according to claim 4, characterized in that, Point P g (x g The coordinates (x, 0) at the previous time step. g The expression for calculating ',0) is: x g '=N1x1'+N2x2' x1≤x g ≤x2 In the formula, x1 represents the current time relative to P. g The x-coordinate of an adjacent boundary node, x2, represents the distance between the current time and P. g The x-coordinate of the adjacent boundary node, x1' represents the coordinate of x1 at the previous time, and x2' represents the coordinate of x2 at the previous time.

6. The field quantity update method for numerical manifold simulation calculation of metal plastic deformation according to claim 5, characterized in that, Point P z (x z ,y z The coordinates (x, y) at the previous time step z ',y z The calculation expression for ') is: x z '=N3x3'+N4x4' x3≤x z ≤x4 or y3≤y z ≤y4 In the formula, the point with coordinates (x3, y3) and the point with coordinates (x4, y4) at the current time are related to point P. z (x z ,y z (x3',y3') represents the coordinates of the point with coordinates (x3,y3) at the previous time step, and (x4',y4') represents the coordinates of the point with coordinates (x4,y4) at the previous time step.

7. The field quantity update method for numerical manifold simulation calculation of metal plastic deformation according to claim 6, characterized in that, Based on point P, point P g and point P z Given the coordinates of the previous moment, calculate the points P and P' of the previous moment. g and point P z The expression for calculating the velocity field under constant coverage is: In the formula, (x,y) represents point P and point P' at the previous time step. g Or point P z The coordinates are given by: u represents the velocity of the point at coordinate (x, y) along the horizontal axis, v represents the velocity of the point at coordinate (x, y) along the vertical axis; (x0, y0) represents the center coordinates of the manifold cell containing the point at coordinate (x, y); a and b represent the length and width of the manifold cell containing the point at coordinate (x, y), respectively. i and v i d1 and d2 represent the velocities of the i-th node in the manifold element containing the point with coordinates (x, y) in the horizontal and vertical directions, respectively; d1 and d2 represent the coverage coefficients of the constant cover; and e represents the manifold element corresponding to the point with coordinates (x, y).

8. The field quantity update method for numerical manifold simulation calculation of metal plastic deformation according to claim 6, characterized in that, Based on point P, point P g and point P z Given the coordinates of the previous moment, calculate the points P and P' of the previous moment. g and point P z The expression for calculating the velocity field under linear coverage is: In the formula, (x,y) represents point P and point P' at the previous time step. g Or point P z The coordinates are given by: u represents the velocity of the point at coordinate (x, y) along the horizontal axis, v represents the velocity of the point at coordinate (x, y) along the vertical axis; (x0, y0) represents the center coordinates of the manifold cell containing the point at coordinate (x, y); a and b represent the length and width of the manifold cell containing the point at coordinate (x, y), respectively. i and v i These represent the i-th node (x, y) of the manifold unit containing the point with coordinates (x, y). i ,y i ) the velocity in the horizontal direction and the velocity in the vertical direction; d3~d8 represent the coverage coefficients of the linear cover with the cover formula [1 xy], and e represents the manifold element corresponding to the point with coordinates (x,y).

9. A field quantity update system for numerical manifold simulation of metal plastic deformation, used to implement the field quantity update method for numerical manifold simulation of metal plastic deformation as described in any one of claims 1 to 8, characterized in that, include: The data acquisition module is used to acquire the node information of the mathematical mesh used for the simulation calculation of metal plastic deformation, the mesh information of the manifold element at the previous time step during the metal plastic deformation process, and the mesh information of the manifold element before the current time step update. The cell information calculation module is used to determine several manifold cells adjacent to the mathematical grid nodes using the node information of the mathematical grid and the grid information of the manifold cells in the previous time step, and to determine the manifold cell number of the point P located at the position of the mathematical grid node in the current time step in the previous time step using the several manifold cells adjacent to the mathematical grid nodes, thus obtaining cell information. The coordinate interpolation calculation module is used to use cell information to represent the coordinates of point P in the manifold cell by interpolating the coordinates of the nodes of the manifold cell at the current time, and to obtain the coordinate interpolation relationship between point P and the nodes of the manifold cell. The first coordinate calculation module is used to calculate the coordinates of point P at the previous moment by using the coordinate interpolation relationship between point P and the nodes of the manifold unit and the node coordinates of the manifold unit at the previous moment. The second coordinate calculation module is used to calculate the point P located at the fixed boundary position of the deformable body's physical geometry at the current moment, using the mesh information of the manifold element at the previous moment and the mesh information of the manifold element before the current moment's update. g and point P located at the free boundary of the deformable body's physical geometry. z The coordinates at the previous moment; The field quantity update module is used to update the field quantity based on point P and point P. g and point P z Given the coordinates of the previous moment, calculate the points P and P' of the previous moment. g and point P z The velocity field quantity is obtained, and the field quantity of the manifold element is updated using the obtained velocity field quantity to obtain the mesh information and field quantity information of the updated manifold element.

10. A computer device comprising a memory and a processor, wherein the memory stores computer-readable instructions, characterized in that, When the computer-readable instructions are executed by the processor, the processor performs the steps of the field quantity update method for numerical manifold simulation calculation of metal plastic deformation as described in any one of claims 1 to 8.

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