JP2021149887A - Relative displacement calculation method and relative displacement calculation device - Google Patents

Abstract

To easily specify magnitude of relative displacement of a joining section of a component for composing a structure.SOLUTION: A relative displacement calculation device 10 acquires displacement information of nodes of plural elements obtained by executing structure analysis to a structure model in which a structure is expressed by plural elements, and joining position information regarding a joining position of plural components for composing a structure, extracts elements of joining surfaces of plural components for composing a structure on the basis of the displacement information and the joining position information, sets a correspondence point corresponding to each node of an element of a joining surface of a first component out of two components that are joined on the joining surface onto an element of a joining surface of a second component joined with the first component on the joining surface, calculates relative displacement of a node corresponding to a correspondence point, and outputs relative displacement in a parallel direction relative to a joining surface in the relative displacement.SELECTED DRAWING: Figure 1

Description

The present invention relates to a relative displacement calculation method and a relative displacement calculation device.

Patent Document 1 describes joining by evaluating the displacement of parts between a state in which no load is applied and a state in which a maximum load is applied to a portion where parts of a structure such as an automobile body are joined to each other. A technology that can easily carry out strengthening measures without relying on the designer's trial and error is disclosed.

In addition, the thinning of high-tensile steel sheets used for automobile bodies has made it possible to achieve both collision safety and weight reduction. However, the thinning of high-tensile steel has made it possible to achieve rigidity and NV (noise / vibration) performance. Decreases.

Further, it is known that when a load is applied to a joint portion where parts such as flanges are joined to each other, the relative displacement between the parts becomes large, and the rigidity is improved by reinforcing with an adhesive or the like. There is. Furthermore, the excitation force is input to the vehicle body from the engine and undercarriage, propagates through the vehicle body skeleton, and the panel parts vibrate and radiate noise. Panel radiation sound can be suppressed.

Japanese Patent No. 6278122

However, if the scope of application of reinforcement is simply expanded, joints that do not originally need to be reinforced, that is, joints where the relative displacement between parts is small, will also be reinforced, causing a decrease in productivity and an increase in cost. .. Therefore, in order to specify the applicable range of appropriate reinforcement, it is necessary to specify the magnitude of the relative displacement.

The present invention has been made in view of the above circumstances, and provides a relative displacement calculation method and a relative displacement calculation device capable of easily specifying the magnitude of relative displacement of joints of parts constituting a structure. It is a thing.

The relative displacement calculation method according to the first aspect includes displacement information of nodes of the plurality of elements obtained by a computer performing structural analysis on a structure model in which the structure is represented by a plurality of elements. The joint position information regarding the joint position of the joint portions of the plurality of parts constituting the structure is acquired, and based on the displacement information and the joint position information, the joint surface of the plurality of parts constituting the structure Each element is extracted, and a process of outputting the relative displacement of the nodes of the elements on the joint surface is executed.

In the relative displacement calculation method according to the second aspect, the computer outputs the relative displacement in the direction parallel to the joint surface among the relative displacements.

In the relative displacement calculation method according to the third aspect, the computer outputs the relative displacement in the direction perpendicular to the joint surface among the relative displacements.

In the relative displacement calculation method according to the fourth aspect, the computer displays in different display modes depending on the magnitude of the relative displacement.

In the relative displacement calculation method according to the fifth aspect, the computer displays a portion where the relative displacement is equal to or higher than a predetermined threshold value in an embodiment indicating that the portion needs to be reinforced.

The relative displacement calculation device according to the sixth aspect includes displacement information of nodes of the plurality of elements obtained by performing structural analysis on a structure model in which the structure is represented by a plurality of elements, and the structure. Based on the acquisition unit for acquiring the joint position information regarding the joint position of the joint portions of the plurality of parts constituting the structure, the displacement information, and the joint position information, the joint surface of the plurality of parts constituting the structure. An extraction unit that extracts each element and a corresponding point corresponding to each node of the element of the joint surface of the first part among the two parts joined at the joint surface are set with the first part and the joint surface. A setting unit set on the element of the joint surface of the second component to be joined in the above, a calculation unit for calculating the relative displacement of the node with respect to the corresponding point, and the relative displacement parallel to the joint surface. It includes an output unit that outputs relative displacement in the direction.

According to the present invention, the magnitude of the relative displacement of the joints of the parts constituting the structure can be easily specified.

It is a block diagram which shows the hardware composition of the relative displacement calculation apparatus. It is a block diagram which shows the functional structure of the relative displacement calculation apparatus. It is a figure which shows an example of the structure which has a flange. It is a figure which shows an example of the FEM model of a structure. It is a figure which shows an example of the case where bending deformation is given to the FEM model of a structure. It is a figure for demonstrating the extraction method of the element of a joint surface. It is a figure for demonstrating the calculation method of a relative displacement. It is a figure for demonstrating the calculation method of a relative displacement. It is a figure for demonstrating the calculation method of a relative displacement. It is a flowchart of a relative displacement calculation process. It is a figure which shows an example of the vehicle body as a structure. It is a figure which shows the display example of the relative displacement in the direction parallel to a joint surface. It is a figure which shows the display example of the relative displacement in the direction perpendicular to a joint surface.

Hereinafter, embodiments of the present invention will be described.

FIG. 1 is a configuration diagram of a relative displacement calculation device 10 according to the present embodiment. The relative displacement calculation device 10 is a device including a general computer, and is composed of, for example, a personal computer or the like.

As shown in FIG. 1, the relative displacement calculation device 10 includes a controller 12. The controller 12 includes a CPU (Central Processing Unit) 12A, a ROM (Read Only Memory) 12B, a RAM (Random Access Memory) 12C, a non-volatile memory 12D, and an input / output interface (I / O) 12E. The CPU 12A, ROM 12B, RAM 12C, non-volatile memory 12D, and I / O 12E are each connected via the bus 12F.

Further, the operation unit 14, the display unit 16, the communication unit 18, and the storage unit 20 are connected to the I / O 12E.

The operation unit 14 includes, for example, a mouse and a keyboard.

The display unit 16 is composed of, for example, a liquid crystal display or the like.

The communication unit 18 is an interface for performing data communication with an external device.

The storage unit 20 is composed of a non-volatile storage device such as a hard disk, and stores the relative displacement calculation program 20A, the displacement information 20B, the junction position information 20C, and the like, which will be described later. The CPU 12A reads and executes the relative displacement calculation program 20A stored in the storage unit 20.

Next, the functional configuration of the CPU 12A when the relative displacement calculation device 10 executes the relative displacement calculation program 20A will be described.

As shown in FIG. 2, the CPU 12A functionally includes an acquisition unit 30, an extraction unit 32, a setting unit 34, a calculation unit 36, and an output unit 38.

The acquisition unit 30 acquires the displacement information 20B of the nodes of the plurality of elements obtained by performing the structural analysis on the structure model in which the structure is represented by the plurality of elements. Further, the acquisition unit 30 acquires the joint position information 20C regarding the joint position of the joint portions of a plurality of parts constituting the structure. The joint position information 20C includes the coordinate values of the joint positions of the joints where the plurality of parts are joined and the part numbers (Part ID, hereinafter referred to as PID) uniquely assigned to each of the plurality of parts to be joined. The associated information. The form of joining includes, but is not limited to, resistance spot welding, arc welding, laser welding, and the like.

As an example, the structure model uses the FEM model used in the numerical analysis method represented by the finite element method (Finite Element Method: hereinafter, FEM). The plurality of elements representing the structure include, for example, shell elements, solid elements, and the like, but are not limited thereto.

FIG. 3 shows, as an example of the structure, a structure 40 formed by forming a thin steel plate and welding and assembling two parts PID1 and PID2 having flanges. The flange FL1 of the component PID1 and the flange FL2 of the component PID2 are joined at predetermined intervals by spot welding as an example.

FIG. 4 shows a structural model 40A in which the structure 40 is represented by an FEM model. In the structure model 40A, the parts PID1 and PID2 are represented by quadrangular shell elements, and the joint SPW of the flanges FL1 and FL2 by spot welding is represented by a rectangular parallelepiped solid element.

By performing a structural analysis by FEM on such a structure model 40A, for example, a structural analysis when a load for bending and deforming the structure model 40A is applied as shown in FIG. 5, each of the plurality of elements is performed. The displacement information 20B of the node is obtained. The obtained displacement information 20B is stored in advance in the storage unit 20.

The acquisition unit 30 acquires the displacement information 20B of each node obtained as a result of the structural analysis by reading it from the storage unit 20. The displacement information 20B includes information on the three-dimensional coordinates of each node after the displacement.

Further, the acquisition unit 30 acquires the joint position information 20C regarding the joint position of the joint SPW of the parts PID1 and PID2 constituting the structure 40 by reading from the storage unit 20. The joint position information 20C can be acquired from, for example, the design information of the structure 40, and is stored in the storage unit 20 in advance.

The extraction unit 32 extracts elements of the joint surface of a plurality of parts constituting the structure, for example, elements of the flange surface, based on the displacement information and the joint position information 20C acquired by the acquisition unit 30. It should be noted that the joint surface is not limited to the flange surface as long as it is a joint surface to which a plurality of parts are joined.

Hereinafter, an example of a method for extracting the joint surface of the structure 40 shown in FIG. 4 will be described.

First, based on the joint position information 20C of the structure 40, the extraction unit 32 sets the element EL1 including the node ND1 closest to the joint position of the joint SPW among the elements of the component PID1 as shown in FIG. 6, for example. Extract.

Next, an element adjacent to the extracted element EL1, that is, an element EL2 that shares the two nodes ND3 and ND4 with the element EL1 is extracted. When the angle θ1 formed by the surface EL1A extending the element EL1 toward the element EL2 and the element EL2 is equal to or less than a predetermined threshold value TH or less, the element EL2 is set as an element candidate for the joint surface (flange surface), and the angle θ1 is the threshold value. If it is larger than TH, it is determined that the element EL2 is not an element candidate of the joint surface. In the example of FIG. 6, since the angle θ1 is equal to or less than the threshold value TH, the element EL2 is determined to be an element candidate of the joint surface.

Further, the same processing is performed on the element EL2. That is, when the element EL3 adjacent to the element EL2 is extracted and the angle θ2 formed by the surface EL2A extending the element EL2 toward the element EL3 and the element EL3 is equal to or less than a predetermined threshold value TH, the element EL3 is used as an element of the joining surface. Make it a candidate. On the other hand, when the angle θ2 is larger than the threshold value TH, it is determined that the element EL3 is not an element candidate of the joint surface. In the example of FIG. 6, since the angle θ2 is larger than the threshold value TH, it is determined that the element EL3 is not an element candidate of the joint surface.

By repeating such a process, all the element candidates constituting the joint surface are extracted from the joint SPW. By executing this for all the joints, all the element candidates of the joint surface with respect to the part PID2 of the part PID1 are extracted.

Then, among the element candidates of the component PID1, the element candidate in which the node of the component PID 2 does not exist within a predetermined distance D from the node of the element candidate is determined not to be an element of the joint surface. On the other hand, among the element candidates of the component PID1, the element candidate in which the node of the component PID 2 exists within a predetermined distance D from the node of the element candidate is determined to be an element of the joint surface.

Then, by executing the same process for the component PID2, all the elements of the joint surfaces of the components PID1 and PID2 are extracted from the joint SPW.

Further, by executing the same process for the other joints, all the elements of the joint surfaces of the parts PID1 and PID2 are extracted.

The setting unit 34 joins the first part and the second part to be joined at the joint surface at the corresponding points corresponding to the nodes of the elements of the joint surface of the part PID1 among the two parts to be joined at the joint surface. Set on the face element.

The calculation unit 36 calculates the relative displacement of the nodes with respect to the corresponding points set by the setting unit 34.

Hereinafter, an example of the setting of the corresponding points and the calculation method of the relative displacement will be described.

For each node included in the element of the joint surface extracted by the extraction unit 32, the relative displacement with the corresponding element is calculated using the displacement information of the node obtained from the analysis result of the numerical analysis by FEM.

First, as shown in FIG. 7, define a normal vector at a certain node N ₀ elements constituting the flange FL1 part number PID1. In the _{elements including the node N 0} (there are a plurality of elements), the _{plane determined by the node N 0} and the two adjacent nodes can be defined as many as the number of elements including _{the node N 0.} These planes unit length normal vector _n i of (i = 1, 2, 3, 4) average (in this case, a simple averaging) of the node _{N 0} vector ^{n N0} with parallel unit length vector Defined as the normal vector in. In the example of FIG. 7, with a unit normal vector n _i, the vector n ^N0 is defined by the following equation.

・・・（１）

... (1)

を用いて、ｓ_１、ｓ_２を次式のように予め定義する。 7 and 8, the intersection of the element surfaces constituting the flange in the direction of the straight line and the part PID2 determined by street vector ^{n N0} nodal _{N 0} and the corresponding point P of the node _{N 0} (pair-point P) It is assumed that the corresponding point P exists in the triangle formed by the three nodes N1, N2, and N3 in the above element. At this time,

Is used to _{define s 1} and s ₂ in advance as in the following equation.

・・・（２）

... (2)

Then, the relative displacement of the node _{N 0} to the corresponding point P, and defined as a relative displacement with respect to the flange FL2 of PID2 at node _{N 0.}

Further, as shown in FIG. 9, it is considered that each point moves to a point with a dash "'" after the transformation. The translational displacement vector u ^P and the rotational displacement vector φ ^P at the corresponding point P are defined as follows.

・・・（３）

・・・（４）

... (3)

... (4)

Here, _{u i} and phi _i (however, i = 1, 2, 3) are each a translational displacement vector and rotational displacement vectors at the nodes _{N i,} can be obtained from the FEM analysis results. Further, the weighting coefficient wi is defined by the following equation.

・・・（５）

... (5)

Here, the matrix C ^P is defined by the following equation.

・・・（６）

... (6)

を次式で定義する。 Here, I ₃ is a 3 × 3 identity matrix, and the rotation axis vector λ ^P and the outer product matrix.

Is defined by the following equation.

・・・（７）

... (7)

Using the matrix C ^P obtained in the above, it calculates the relative displacement S by the following equation.

・・・（８）

... (8)

Further, when n'= C ^P n, _{the relative displacement (gap change, gap change) vector S ⊥ in the} direction perpendicular to the joint surface of the component PID 2 at the _{node N 0} and the parallel direction (relative slip, relative) to the joint surface of the component PID 2 Sliding) Vector S _‖ is expressed by the following equation.

・・・（９）

... (9)

Then, the relative displacement distribution can be obtained by executing the above processing for all the nodes included in the elements of the joint surface.

The output unit 38 outputs the relative displacement in the direction parallel to the joint surface among the relative displacements calculated by the calculation unit 36. For example, the relative displacement is displayed on the display unit 16 or stored in the storage unit 20. At this time, the display unit 16 may display different display modes depending on the magnitude of the relative displacement. Further, the portion where the relative displacement is equal to or larger than the predetermined threshold value may be displayed in a manner indicating that the portion needs to be reinforced. Further, among the relative displacements calculated by the calculation unit 36, the relative displacements in the direction perpendicular to the joint surface may be output.

Hereinafter, the relative displacement calculation process executed by the CPU 12A will be described with reference to the flowchart shown in FIG. The relative displacement calculation process shown in FIG. 10 is executed by reading the relative displacement calculation program from the storage unit 20, for example, when the user operates to instruct the execution of the relative displacement calculation program. Further, in the following, a case of calculating the relative displacement of the joint surfaces of the parts constituting the vehicle body 50 of the automobile as shown in FIG. 11 will be described. The vehicle body 50 is a middle-class hatchback type (5-door) that is widely available on the market as an example.

Before executing the relative displacement calculation program, structural analysis is performed when, for example, bending deformation is applied to the FEM model of the vehicle body 50. As a result, the displacement information 20B of each node of the plurality of elements constituting the FEM model of the vehicle body 50 can be obtained. Then, the obtained displacement information 20B is stored in the storage unit 20. Further, the joint position information 20C regarding the joint positions of the joint portions of the plurality of parts constituting the vehicle body 50 is acquired from, for example, the design information of the vehicle body 50 and stored in the storage unit 20.

In step S100, the CPU 12A, as the acquisition unit 30, displacement information 20B of each node of a plurality of elements constituting the FEM model of the vehicle body 50 and joint position information regarding the joint position of the joint portions of the plurality of parts constituting the vehicle body 50. 20C and 20C are acquired by reading from the storage unit 20.

In step S102, the CPU 12A, as the extraction unit 32, extracts the elements of the joint surfaces of the plurality of parts constituting the vehicle body 50 based on the displacement information and the joint position information acquired in step S100.

In step S104, the CPU 12A, as the setting unit 34, sets the corresponding points corresponding to the nodes of the elements of the joint surface of the first component among the two components joined at the joint surface at the joint surface with the first component. It is set on the element of the joint surface of the second component to be joined. This is performed for the joint surfaces of all the parts of the vehicle body 50.

In step S106, the CPU 12A, as the calculation unit 36, calculates the relative displacement of the nodes with respect to the corresponding points. This is performed for the joint surfaces of all the parts of the vehicle body 50.

_{In step S108, the CPU 12A outputs the relative displacement S ‖ in the} direction parallel to the joint surface among the relative displacements calculated in step S106 as the output unit 38. For example, as shown in FIG. 12, the relative displacement S _‖ of the vehicle body 50 is displayed on the display unit 16 or stored in the storage unit 20. In the example of FIG. 13, the display mode is different by color-coding according to the magnitude of the relative displacement.

Further, for example, as shown in FIG. 13, of the relative displacements calculated in step S106, the relative displacement S _{⊥ in the} direction perpendicular to the joint surface is displayed on the display unit 16 or stored in the storage unit 20. May be good.

Further, a portion where the relative displacement is equal to or higher than a predetermined threshold value may be displayed in a manner indicating that the portion needs to be reinforced. For example, by displaying only the portion where the relative displacement is equal to or greater than the predetermined threshold value, the portion requiring reinforcement and the portion not requiring reinforcement may be clearly distinguished.

As described above, in the present embodiment, the displacement information of each node of the plurality of elements obtained by performing the structural analysis on the structure model in which the structure is represented by the plurality of elements and the structure are constructed. Based on the joint position information regarding the joint positions of the joint portions of the plurality of parts, the elements of the joint surfaces of the plurality of parts constituting the structure are extracted. Then, of the two parts to be joined at the joint surface, the corresponding points corresponding to the nodes of the elements of the joint surface of the first part are set to the joint surfaces of the second component to be joined at the joint surface with the first component. It is set on the element of, and the relative displacement of the node with respect to the corresponding point is calculated and output. Thereby, the magnitude of the relative displacement of the joints of the parts constituting the structure can be easily specified.

In the present embodiment, the mode in which the relative displacement calculation program is stored (installed) in the storage unit 20 in advance has been described, but the present invention is not limited to this. The relative displacement calculation program is recorded on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versaille Disc Read Only Memory), and a USB (Universal Serial Bus) memory. May be good. Further, the relative displacement calculation program may be downloaded from an external device via a network.

10 Relative displacement calculation device 12 Controller 14 Operation unit 16 Display unit 18 Communication unit 20 Storage unit 20A Relative displacement calculation program 20B Displacement information 20C Joint position information 30 Acquisition unit 32 Extraction unit 34 Setting unit 36 Calculation unit 38 Output unit 40 Structure

Claims (6)

The computer
Displacement information of nodes of the plurality of elements obtained by performing structural analysis on a structure model in which the structure is represented by a plurality of elements, and joints of joints of a plurality of parts constituting the structure. Get the joint position information about the position,
Based on the displacement information and the joint position information, the elements of the joint surfaces of the plurality of parts constituting the structure are extracted.
A relative displacement calculation method for executing a process of outputting the relative displacement of the nodes of the elements of the joint surface. The computer
The relative displacement calculation method according to claim 1, wherein the relative displacement in the direction parallel to the joint surface is output among the relative displacements. The computer
The relative displacement calculation method according to claim 1 or 2, wherein the relative displacement in the direction perpendicular to the joint surface is output among the relative displacements. The computer
The relative displacement calculation method according to any one of claims 1 to 3, wherein the display is performed in a different display mode depending on the magnitude of the relative displacement. The relative displacement calculation method according to any one of claims 1 to 4, wherein the computer displays a portion where the relative displacement is equal to or higher than a predetermined threshold value in a manner indicating that the portion requires reinforcement. Displacement information of nodes of the plurality of elements obtained by performing structural analysis on a structure model in which the structure is represented by a plurality of elements, and joints of joints of a plurality of parts constituting the structure. An acquisition unit that acquires joint position information related to the position, and
An extraction unit that extracts elements of the joint surface of a plurality of parts constituting the structure based on the displacement information and the joint position information.
Of the two parts to be joined at the joint surface, the corresponding points corresponding to the nodes of the elements of the joint surface of the first part are set to the corresponding points of the second part to be joined to the first part at the joint surface. A setting unit set on the element of the joint surface and
A calculation unit that calculates the relative displacement of the node with respect to the corresponding point,
An output unit that outputs the relative displacement in the direction parallel to the joint surface among the relative displacements,
Relative displacement calculation device equipped with.

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