JP5081844B2 - Deformation amount evaluation support apparatus, deformation amount evaluation support method, and program - Google Patents

Description

  The present invention relates to a deformation amount evaluation support apparatus, a deformation amount evaluation support method, and a program for supporting evaluation of a deformation amount of a cross section of an object.

  Conventionally, a test for evaluating the rigidity of a vehicle body has been performed. Examples of such tests include a cantilever test in which the rear suspension attachment point is fixed and a load is applied in the lateral direction of the front suspension attachment point, the rear upper support is fixed, and the front left and right upper supports are fixed. There is a torsion test that applies a load in the opposite direction. Further, Patent Document 1 describes an evaluation method that can accurately evaluate the operability, a measurement point specifying method that specifies a measurement unit to be measured, and the like.

JP 2002-107272 A

  However, since the conventional evaluation method can only obtain information on the sum of the components constituting the deformation amount, side-by-side evaluation is possible, but as design change information for suppressing the deformation amount at a certain point of the vehicle body Is insufficient. The amount of deformation measured is composed of a bending component, a rigid body rotation component (hereinafter simply referred to as a rotation component), and a strain component. If these are evaluated without being separated, it is necessary to consider measures for reinforcement. I have to rely on experience.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a deformation amount evaluation support device and the like that can separate and quantitatively evaluate a bending component, a rotation component, and a strain component that constitute a deformation amount. It is.

In order to achieve the above-described object, a first invention is a deformation amount evaluation support apparatus that supports evaluation of a deformation amount of a cross section of an object, and is a first setting means for setting a shear center point of a cross section of an evaluation object. And the coordinate (Y, Z) of the pre-deformation calculation point in the cross section to be evaluated, the coordinates of the post-deformation calculation point corresponding to the pre-deformation calculation point (y, z) ) And a second setting means for setting y = a ₁ Y + b ₁ Z + c ₁ and z = a ₂ Y + b ₂ Z + c ₂ , coefficients a ₁ , b ₁ , c ₁ , a ₂ , b ₂ , c ₂ are calculated. Using the first calculation means and an expression indicating that the coefficients a ₁ , a ₂ , b ₁ , b ₂ and the deformation gradient tensor are equivalent, the deformation state of the cross section to be evaluated is expressed as a bending component, a rotation component, A second calculating means for separating the strain components and calculating a quantitative value of each component; Bending components, the rotating component, a deformation amount evaluation support apparatus characterized by comprising an output means for outputting the quantitative value of each component of the distortion components.

The second calculation means in the first invention calculates a displacement gradient tensor from the deformation gradient tensor, separates the displacement gradient tensor into a symmetric tensor and an antisymmetric tensor, calculates a quantitative value of the strain component from the symmetric tensor, A quantitative value of the rotational component is calculated from the antisymmetric tensor, and a quantitative value of the bending component is calculated from the coefficients c ₁ and c ₂ . The second calculation means preferably calculates a quantitative value of the compressive strain component from the diagonal component of the symmetric tensor and calculates a quantitative value of the shear strain component from the non-diagonal component of the symmetric tensor.

  The output means in the first invention includes, for example, the first shape before deformation, and the second shape and third shape after individually applying deformation by the three components of the bending component, the rotation component, and the strain component. The fourth shape is displayed. The output unit displays, for example, the displacement amount due to the bending component, the rotation component, and the strain component for each arbitrary point in the cross section to be evaluated.

A second invention is a deformation amount evaluation support method for supporting an evaluation of a deformation amount of a cross section of an object, the first setting step of setting a shear center point of a cross section to be evaluated, and the shear center point as an origin The second setting for setting the coordinates (Y, Z) of the pre-deformation calculation point in the cross section to be evaluated and the coordinates (y, z) of the post-deformation calculation point corresponding to the calculation point before the deformation And a _first calculation step for calculating coefficients a ₁ , b ₁ , c ₁ , a ₂ , b ₂ , c ₂ of y = a ₁ Y + b ₁ Z + c ₁ , z = a ₂ Y + b ₂ Z + c ₂ , Using a formula indicating that the coefficients a ₁ , a ₂ , b ₁ , b ₂ and the deformation gradient tensor are equivalent, the deformation state of the cross section to be evaluated is separated into a bending component, a rotation component, and a strain component, A second calculation step of calculating a quantitative value of the component, the bending component, Serial rotation component, a deformation amount evaluation support method characterized by comprising an output step of outputting the quantitative value of each component of the distortion components.

  A third invention is a program for causing a computer to function as the deformation amount evaluation support apparatus of the first invention.

  With the deformation amount evaluation support apparatus of the present invention, the bending component, the rotation component, and the strain component constituting the deformation amount can be separated and quantitatively evaluated.

Computer hardware configuration diagram The flowchart which shows the detail of operation | movement of the deformation amount evaluation assistance apparatus 1. Diagram for explaining measurement points before deformation Diagram showing an example of shear center point Diagram showing an example of an object before deformation A figure showing an example of a deformed object The figure which shows the example of a display of the quantitative value of each ingredient The figure which shows an example of the output of the displacement amount by each component for every calculation point The figure which shows an example of the output of the displacement amount by each component for every calculation point The figure which shows an example of the output of the displacement amount by each component for every calculation point The figure which shows an example of the output of the displacement amount by each component for every calculation point

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a hardware configuration diagram of a computer that realizes a deformation amount evaluation support apparatus 1 according to an embodiment of the present invention. Note that the hardware configuration in FIG. 1 is an example, and various configurations can be adopted depending on the application and purpose.

  The deformation amount evaluation support apparatus 1 includes a control unit 3, a storage unit 5, a media input / output unit 7, a communication control unit 9, an input unit 11, a display unit 13, a peripheral device I / F unit 15, and the like via a bus 17. Connected.

  The control unit 3 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like.

The CPU calls and executes a program stored in the storage unit 5, ROM, recording medium, etc. to a work memory area on the RAM, drives and controls each device connected via the bus 17, and a deformation amount evaluation support device 1 to realize the later-described processing.
The ROM is a non-volatile memory and permanently holds a computer boot program, a program such as BIOS, data, and the like.
The RAM is a volatile memory, and temporarily stores programs, data, and the like loaded from the storage unit 5, ROM, recording medium, and the like, and includes a work area used by the control unit 3 for performing various processes.

The storage unit 5 is an HDD (hard disk drive), and stores a program executed by the control unit 3, data necessary for program execution, an OS (operating system), and the like. With respect to the program, a control program corresponding to an OS (operating system) and an application program for causing a computer to execute processing described later are stored.
Each of these program codes is read by the control unit 3 as necessary, transferred to the RAM, read by the CPU, and executed as various means.

  The media input / output unit 7 (drive device) inputs / outputs data, for example, a CD drive (-ROM, -R, -RW, etc.), DVD drive (-ROM, -R, -RW, etc.), MO drive, etc. And other media input / output devices.

  The communication control unit 9 includes a communication control device, a communication port, and the like, and is a communication interface that mediates communication between the computer and the network 19, and performs communication control between other computers via the network 19.

The input unit 11 inputs data and includes, for example, a keyboard, a pointing device such as a mouse, and an input device such as a numeric keypad.
An operation instruction, an operation instruction, data input, and the like can be performed on the computer via the input unit 11.

  The display unit 13 includes a display device such as a CRT monitor and a liquid crystal panel, and a logic circuit (such as a video adapter) for realizing a video function of the computer in cooperation with the display device.

  The peripheral device I / F (interface) unit 15 is a port for connecting a peripheral device to the computer, and the computer transmits and receives data to and from the peripheral device via the peripheral device I / F unit 15. The peripheral device I / F unit 15 is configured by USB, IEEE 1394, RS-232C, or the like, and usually has a plurality of peripheral devices I / F. The connection form with the peripheral device may be wired or wireless.

  The bus 17 is a path that mediates transmission / reception of control signals, data signals, and the like between the devices.

  FIG. 2 is a flowchart showing details of the operation of the deformation amount evaluation support apparatus 1. The deformation amount evaluation support apparatus 1 targets a cross-section of an object as an evaluation target, coordinates of a shear center point of the cross-section to be evaluated, coordinates of a pre-deformation calculation point in the cross-section, and post-deformation calculation points corresponding to the pre-deformation calculation points. Using coordinates as input, the amount of deformation of the object is separated into a bending component, a rotation component, and a strain component, and a quantitative value is calculated and output.

  FIG. 3 is a diagram illustrating an example of an evaluation target. Reference numeral 21 denotes a cylindrical rectangular parallelepiped, which is an object to be evaluated. A region 23 indicated by a right-downward parallel oblique line is parallel to the YZ plane and is a cross section to be evaluated. Arrows 25 and 27 indicate loads applied to the object 21. A region 29 indicated by a right-upward parallel oblique line is parallel to the YZ plane and is a fixed end surface. Hereinafter, the details of the operation of the deformation amount evaluation support apparatus 1 will be described by taking the shape of the object, the boundary condition, the cross-sectional position of the evaluation target, and the load condition shown in FIG. 3 as examples.

  As shown in FIG. 2, the control unit 3 of the deformation amount evaluation support apparatus 1 sets the shear center point of the cross section to be evaluated (S101). The coordinates of the shear center point can be calculated from the shape of the object, the boundary condition, the cross-sectional position of the evaluation target, the load condition, and the like by numerical analysis. The shear center point may be input via the input unit 11.

  FIG. 4 is a diagram illustrating an example of the shear center point. Point 31 is the shear center point. The shear center point 31 is a point on the cross section 23 to be evaluated. For processing to be described later, the control unit 3 sets a two-dimensional (YZ plane) coordinate system having the shear center point 31 as the origin, as shown in FIG.

  In the coordinate system having the origin of the shear center point set in S101, the control unit 3 coordinates the calculation points before deformation (Y, Z) and the coordinates (y, z) of the calculation points after deformation corresponding to the calculation points before deformation. ) Is set (S102).

  FIG. 5 is a diagram illustrating an example of an object before deformation. A region 23a indicated by a right-downward parallel oblique line is a cross section of an evaluation target before deformation. Reference numerals 33a, 35a, 37a, and 39a are pre-deformation calculation points. The number of calculation points is not limited to four but may be at least three. The reason why at least three are necessary will be described later in the description of S103. The coordinates (Y, Z) of the pre-deformation calculation point are input via the input unit 11, for example.

  FIG. 6 is a diagram illustrating an example of the deformed object. The deformed object 21b shown in FIG. 6 is deformed by the load by the arrows 25 and 27 shown in FIG. A region 23b indicated by a right-downward parallel oblique line is a cross section of an evaluation target before deformation. Reference numerals 33b, 35b, 37b, and 39b are post-deformation calculation points. The shape of the deformed object 21b can be calculated by numerical analysis (for example, a finite element method or the like), and coordinates (y, z) of the calculated calculation point can be obtained.

  Note that the coordinates of the shear center point, the coordinates of the pre-deformation calculation points, and the coordinates of the post-deformation calculation points may be based on the results of an actually performed rigidity evaluation test, without using numerical analysis. That is, the present invention can be applied not only to simulation by numerical analysis but also to actual test results.

Returning to the description of FIG. The control unit 3 determines the coordinates (y, z) of the post-deformation calculation point.
y = a ₁ Y + b ₁ Z + c ₁ (1),
z = a ₂ Y + b ₂ Z + c ₂ (2),
The coefficients a ₁ , b ₁ , c ₁ , a ₂ , b ₂ , c ₂ are calculated (S103).

Since the equations (1) and (2) each have three undetermined coefficients, the coefficients a ₁ , b ₁ , c ₁ , a ₂ , b ₂ , and c ₂ can be calculated if there are at least three calculation points. . When there are four or more calculation points, the coefficients a ₁ , b ₁ , c ₁ , a ₂ , b ₂ , and c ₂ are calculated using a technique such as regression analysis.

  Hereinafter, the process of S103 will be described. The deformation gradient tensor L, which is defined as an operator that relates the positions of two-dimensional arbitrary points before and after the motion, assumes that the coordinates before the motion are (y, z) and the coordinates after the motion are (Y, Z). It is defined by an expression.

The deformation gradient tensor L can be expressed using the coefficients a ₁ , b ₁ , a ₂ , and b ₂ from the expressions (1) and (2) as shown in the following expression. That is, the coefficients a ₁ , a ₂ , b ₁ , b ₂ and the deformation gradient tensor are equivalent.

  Here, the displacement gradient tensor D is defined by the following equation.

The displacement gradient tensor D and the deformation gradient tensor L are
[D] = [L] −I (6)
The relationship holds.

  Further, when the displacement gradient tensor D is separated into a symmetric tensor M and an antisymmetric tensor N as shown in the following equation, the diagonal term of the symmetric tensor indicates the compressive strain component, and the off-diagonal term of the symmetric tensor indicates the shear strain component. ing. In addition, the off-diagonal term of the antisymmetric tensor indicates the rotation component.

The symmetric tensor M and antisymmetric tensor N are obtained from the equations (4), (5), (6), and (7) using the coefficients a ₁ , b ₁ , a ₂ , and b ₂ as shown in the following equation. Can be represented.

Therefore, by solving the equations (1) and (2) and calculating the coefficients a ₁ , b ₁ , a ₂ , and b ₂ , the symmetric tensor M and the antisymmetric tensor N can be obtained, and the distortion component, rotation The quantitative value of the component can be obtained.

In addition, the coefficients c ₁ and c ₂ in the expressions (1) and (2) indicate the movement amount in the cross section of the evaluation target before deformation, and are equivalent to the bending component. Therefore, by solving the equations (1) and (2) and calculating the coefficients c ₁ and c ₂ , a quantitative value of the bending component can be obtained.

As described above, in S103, the coefficients a ₁ , b ₁ , c ₁ , a ₂ , b ₂ , and c ₂ in equations (1) and (2) are calculated, thereby quantifying strain components, rotational components, and bending components. A value can be obtained.

Returning to the description of FIG. The control unit 3 calculates quantitative values of the bending component, the rotation component, and the strain component (S104). The control unit 3 substitutes the values of the coefficients a ₁ , b ₁ , a ₂ , and b ₂ of the equations (1) and (2) calculated in S103 into the equations (8) and (9), thereby rotating components The quantitative value of the strain component is calculated. Further, the control unit 3 calculates the coefficients c ₁ and c ₂ of the expressions (1) and (2) calculated in S103 as the quantitative values of the bending component.

  The control unit 3 outputs quantitative values of the bending component, the rotation component, and the strain component (S105). For example, the control unit 3 displays the quantitative values of the bending component, the rotation component, and the strain component on the display unit 13.

  FIG. 7 is a diagram illustrating a display example of quantitative values of each component. A rectangle A shown in FIG. 7 indicates a cross section of an evaluation target before deformation. A rectangle B shows a cross section of an evaluation target after the bending component is deformed with respect to the rectangle A. A rectangle C shows a cross section of an evaluation target after the rotation component is deformed with respect to the rectangle B. A rectangle D indicates a cross section of an evaluation target after the deformation of the strain component is applied to the rectangle C.

Adding bending deformation of the component is to be moved by c ₂ to c _1, Z direction in the Y direction with respect to an arbitrary point. Adding the deformation of the rotation component is to apply the rotation defined by the equation (9) to an arbitrary point. Applying the deformation of the strain component is to apply compression and shear defined by the equation (8) to an arbitrary point. A rectangle D indicating the state after the deformation of the bending component, the rotation component, and the strain component is applied to the rectangle A matches the cross section of the evaluation target after the deformation. The rectangles A, B, C, and D may all be displayed at the same time, or may be displayed in the order of the rectangles A, B, C, and D.

  Note that the order of applying the deformation of each component is not limited to the order of the bending component, the rotation component, and the strain component, and can be performed in any order. Further, in the above description, the target to which the deformation of each component is changed in the order of the rectangle A, the rectangle B, and the rectangle C, but the target to be deformed of each component may be all the rectangle A. That is, the state after the deformation of only individual components may be displayed on the cross section of the evaluation target before the deformation.

  FIG. 8 to FIG. 11 are diagrams showing an example of the output of the displacement amount by each component for each calculation point. FIG. 8 shows the output of the displacement amount by each component regarding the pre-deformation calculation point 33a and the post-deformation calculation point 33b. FIG. 9 shows the output of the displacement amount by each component regarding the pre-deformation calculation point 35a and the post-deformation calculation point 35b. FIG. 10 shows the output of the displacement amount by each component regarding the pre-deformation calculation point 37a and the post-deformation calculation point 37b. FIG. 11 shows an output of the displacement amount by each component regarding the pre-deformation calculation point 39a and the post-deformation calculation point 39b. In this example, a load giving a shear strain is applied, and the displacement amount of the strain component (mainly the shear strain component) is large. In addition, based on the calculation result of S104, the displacement amount by each component can be output for every arbitrary point in the cross section to be evaluated in addition to the calculation point.

  According to the deformation amount evaluation support apparatus 1 according to the embodiment of the present invention, the coordinates of the shear center point of the cross section to be evaluated, the coordinates of the pre-deformation calculation points in the cross section, the post-deformation calculation points corresponding to the pre-deformation calculation points. From the coordinates, a quantitative value obtained by separating the deformation amount of the object into a bending component, a rotation component, and a strain component can be obtained. As a result, the designer of the vehicle body or the like can select an appropriate reinforcement location by paying attention to the component that greatly contributes to the deformation, and can avoid excessive reinforcement.

  The preferred embodiments of the deformation amount evaluation support apparatus and the like according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these naturally belong to the technical scope of the present invention. Understood.

DESCRIPTION OF SYMBOLS 1 ......... Deformation amount evaluation assistance apparatus 3 ......... Control part 5 ......... Storage part 7 ......... Media input / output part 9 ......... Communication control part 11 ......... Input part 13 ......... Display part 15 ... ...... Peripheral device I / F unit 17 ......... Bus 19 ......... Network 21 ......... Object to be evaluated 21a ...... Object to be evaluated before deformation 21b ......... Object to be evaluated after deformation 23 ... …… Cross section 23a ………… Cross section 23b ………… Cross section 25, 27 ………… Load applied to the object 21 29 ………… Fixed end face 31 ………… Shear Center point 33a, 35a, 37a, 39a ......... Calculation point before deformation 33b, 35b, 37b, 39b ......... Calculation point after deformation

Claims (7)

A deformation amount evaluation support device that supports the evaluation of the deformation amount of a cross section of an object,
First setting means for setting a shear center point of a cross section to be evaluated;
In the coordinate system with the shear center point as the origin, the coordinates (Y, Z) of the pre-deformation calculation point in the cross section to be evaluated, and the coordinates (y, z) of the post-deformation calculation point corresponding to the pre-deformation calculation point A second setting means for setting;
first calculating means for calculating coefficients a ₁ , b ₁ , c ₁ , a ₂ , b ₂ , c ₂ of y = a ₁ Y + b ₁ Z + c ₁ , z = a ₂ Y + b ₂ Z + c ₂ ;
Using the equation indicating that the coefficients a ₁ , a ₂ , b ₁ , b ₂ and the deformation gradient tensor are equivalent, the deformation state of the cross section to be evaluated is separated into a bending component, a rotation component, and a strain component, A second calculating means for calculating a quantitative value of each component;
Output means for outputting a quantitative value of each component of the bending component, the rotation component, and the strain component;
A deformation amount evaluation support apparatus comprising: The second calculating means calculates a displacement gradient tensor from the deformation gradient tensor, separates the displacement gradient tensor into a symmetric tensor and an antisymmetric tensor, calculates a quantitative value of the strain component from the symmetric tensor, The deformation amount evaluation support apparatus according to claim 1, wherein a quantitative value of the rotational component is calculated from the antisymmetric tensor, and a quantitative value of the bending component is calculated from the coefficients c ₁ and c ₂ .   The second calculation means calculates a quantitative value of a compressive strain component from a diagonal component of the symmetric tensor and calculates a quantitative value of a shear strain component from an off-diagonal component of the symmetric tensor. Item 3. The deformation amount evaluation support device according to Item 2.   The output means includes a first shape before deformation, and a second shape, a third shape, and a fourth shape after individually applying deformation by the three components of the bending component, the rotation component, and the strain component. The deformation amount evaluation support apparatus according to claim 1, wherein each of the shapes is displayed.   The deformation amount evaluation support apparatus according to claim 1, wherein the output unit displays a displacement amount due to the bending component, the rotation component, and the strain component for each arbitrary point in the cross section of the evaluation target. . A deformation amount evaluation support method for supporting the evaluation of the deformation amount of a cross section of an object,
A first setting step for setting a shear center point of a cross section to be evaluated;
In the coordinate system with the shear center point as the origin, the coordinates (Y, Z) of the pre-deformation calculation point in the cross section to be evaluated, and the coordinates (y, z) of the post-deformation calculation point corresponding to the pre-deformation calculation point A second setting step to set;
a _first calculation step of calculating coefficients a ₁ , b ₁ , c ₁ , a ₂ , b ₂ , c ₂ of y = a ₁ Y + b ₁ Z + c ₁ , z = a ₂ Y + b ₂ Z + c ₂ ;
Using the equation indicating that the coefficients a ₁ , a ₂ , b ₁ , b ₂ and the deformation gradient tensor are equivalent, the deformation state of the cross section to be evaluated is separated into a bending component, a rotation component, and a strain component, A second calculation step for calculating a quantitative value of each component;
An output step of outputting a quantitative value of each component of the bending component, the rotation component, and the strain component;
A deformation amount evaluation support method characterized by comprising:   A program causing a computer to function as the deformation amount evaluation support apparatus according to claim 1.

Images