JP2007179175A - Mastic adhesive modeling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for simply and quickly modeling mastic adhesives of different sizes and values of physical properties. <P>SOLUTION: A mastic adhesive modeling method, for generating an analysis model of the mastic adhesive 22 for performing finite element analysis of components 20, 21 including portions to be bonded with the mastic adhesive 22, includes an information acquisition step S1 for acquiring information on the mastic adhesive 22, an element division step S2 for dividing the mastic adhesive into a plurality of solid elements, and an information setting step S3 for setting information on the mastic adhesive 22 acquired in the information acquisition step S1 as information on the solid elements of the mastic adhesive 22 divided in the element division step S2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for modeling a mastic adhesive in a CAE (Computer Aided Engineering) system, and more particularly, by dividing the mastic adhesive into a plurality of solid elements and modeling them, thereby obtaining dimensions and physical property values. The present invention relates to a method for quickly and quickly modeling different mastic adhesives.

  The CAE system is a computer system for analyzing heat, fluid, electromagnetic field, structure, climate and the like, and includes a preprocessor unit, a solver unit, and a postprocessor unit.

  The preprocessor unit models the shape of the analysis target (creates a shape model), divides the mesh (creates an analysis model), or sets physical properties such as Young's modulus and Poisson's ratio, or analysis conditions such as load conditions and constraint conditions Is a software that allows the user to perform the operation via a GUI (Graphical User Interface).

  The solver unit is an arithmetic processing unit that performs analysis or the like by a finite element method (FEM (Finite Element Method)) based on data for analysis created by the preprocessor unit.

  In addition, the post-processor unit has a function to post-process various analysis results such as displacement, stress, temperature output by the solver unit, and to display the processing results on a display etc., filing in an appropriate format, This is software that evaluates or determines whether it is useful as design data.

Some of these CAE systems have an adaptive mesh function that automatically re-executes mesh division to obtain a better analysis result based on the analysis result of the solver unit. There is also known one having a function of inheriting the analysis conditions input to the shape element of the analysis model generated from the shape model (see, for example, Patent Document 1).
Japanese Patent No. 3221137

  However, in the conventional CAE system, when modeling a mastic adhesive that is a part of an analysis target, one mastic adhesive is modeled as a single solid element, so the dimensions and physical properties of the mastic adhesive. Each time the value changes, it is necessary to adjust the physical property value of the solid element, which is an analysis model, to a physical property value suitable for the actual dimensions and physical property values of the mastic adhesive. Further, the invention described in Patent Document 1 does not mention modeling of a mastic adhesive.

  In view of the above-described problems, an object of the present invention is to provide a method for easily and quickly modeling mastic adhesives having different dimensions and physical property values.

  To achieve the above object, the mastic adhesive modeling method according to the first invention generates a mastic adhesive analysis model for performing finite element analysis of a part including a portion bonded by the mastic adhesive. A mastic adhesive modeling method for acquiring information on the mastic adhesive, an element dividing step for dividing the mastic adhesive into a plurality of solid elements, and acquired in the information acquiring step An information setting step of setting information on the mastic adhesive as information on the solid element of the mastic adhesive divided in the element dividing step.

  A second invention is a mastic adhesive modeling method according to the first invention, wherein in the information setting step, information on the mastic adhesive set for each of the solid elements is the mastic adhesive. It is a physical property value of the agent.

  By the above-mentioned means, the present invention can provide a method for easily and quickly modeling mastic adhesives having different dimensions and physical property values.

  Hereinafter, the best mode for carrying out the present invention will be described in several embodiments with reference to the drawings.

  FIG. 1 is a schematic block diagram of a CAE system according to the present invention. The CAE system 100 includes an HDD (Hard Disk Drive) 1, a display 2, an input device 3, a CPU (Central Processing Unit) 4 and a RAM (Random Access Memory) 5.

  The HDD 1 is a non-volatile storage device, and stores a preprocessor 10, a solver 11, and a post processor 12.

  The display 2 is a display device for displaying the analysis result output by the post processor 12.

  The input device 3 is a keyboard or a mouse for inputting physical property values such as rigidity, Young's modulus, Poisson's ratio, and attenuation to the preprocessor 10.

  The CPU 4 is an arithmetic processing unit, and expands the preprocessor 10, solver 11, and postprocessor 12 stored in the HDD 1 in the RAM 5, and performs processing such as shape modeling, analysis modeling, FEM analysis processing, and image processing of an analysis target. Execute.

  The RAM 5 is a nonvolatile memory and provides work areas such as the preprocessor 10, the solver 11, and the postprocessor 12.

  FIG. 2 is a diagram showing a mastic adhesive model. FIG. 2A shows a perspective view of the mastic adhesive analysis model, and FIG. 2B shows a front view of the mastic adhesive analysis model. When the physical property value of the mastic adhesive 22 is input to the preprocessor 10, the CAE system 100 displays an analysis model of the mastic adhesive on the display 2.

  Here, the mastic adhesive is an elastic adhesive mainly composed of synthetic rubber, which bonds a vehicle hood, door, bonnet, roof, trunk lid or other outer plate to a reinforcing plate or other inner plate. Used to improve rigidity and prevent vibration and noise of the outer plate.

  The analysis model of the mastic adhesive is composed of the first component 20, the second component 21, and the mastic adhesive 22 that bonds the first component 20 and the second component 21. Based on the dimensions of the mastic adhesive inputted via the above, it is divided into three parts in the height direction, two parts in the length direction and the width direction, respectively, and automatically divided into a plurality of solid elements.

  Here, a solid element is an element expressed by a solid model, which is a solid representation method used in finite element analysis, and has the information of vertices, ridges, faces and masses, and the shape closest to the actual object. Is an element that expresses

  Note that the physical property values (Young's modulus, Poisson's ratio, etc.) of the mastic adhesive inputted via the input device 3 are applied as they are to the divided solid elements.

  An element 23 indicated by a dotted line in FIG. 2B is an interpolation constraint element 23 that connects each node on the upper surface or the lower surface of the mastic adhesive analysis model and each node of the first component 20 or the second component 21. Yes, for modeling the transition region between the first part 20 or the second part 21 and the mastic adhesive 22.

  Next, the difference between the conventional modeling method and the modeling method according to the present invention will be described. FIG. 3 is a diagram illustrating deformation caused by a load acting on the mastic adhesive. FIGS. 4 and 5 are deformations generated when a predetermined load is applied to the mastic adhesive divided into a predetermined number of elements. It is a figure which shows the analysis result.

  First, FIG. 3A shows a mastic adhesive 22A that is divided into three parts in the height direction and two parts in the length direction and the width direction (hereinafter referred to as “multiple parts”) according to the present invention. A state in which a vertical direction (compression direction) load VL (for example, 40 N) is applied from above is shown. When a vertical load VL is applied to the plurality of divided mastic adhesives 22A, the plurality of divided mastic adhesives 22A are distorted downward by a deformation amount VD1 and divided into a plurality of pieces as shown in FIG. The mastic adhesive 22B is brought into a state.

  FIG. 3C shows a conventional CAE system in which a vertical load VL is applied to a mastic adhesive 22C that is not divided into a plurality of parts and treated as one element (hereinafter referred to as “not divided into a plurality of parts”). The state added from is shown. When the vertical load VL is applied to the non-divided mastic adhesive 22C, as shown in FIG. 3D, the non-divided mastic adhesive 22C is distorted downward by the deformation amount VD2, and is divided into plural pieces. It will be in the state of mastic adhesive 22D which is not done.

  Here, each of the solid elements of the mastic adhesive 22A divided into a plurality of pieces and the mastic adhesive 22C not divided into a plurality of pieces are calculated to have the same physical property values, and the difference in the number of divisions is calculated. Therefore, the deformation amount VD1 and the deformation amount VD2 have different values. In general, the mastic adhesive 22C that is not divided into multiple pieces cannot express deformation of the adhesive that is an elastic body, and tends to be more rigid than the actual one. Therefore, in the conventional CAE system, multiple divisions are required. The physical property value of the mastic adhesive 22C that has not been changed is changed, the analysis process is executed again, and the physical property values are adjusted until rigidity close to the actual material is obtained.

  On the other hand, the mastic adhesive 22A divided into a plurality according to the present invention has an analysis result calculated on the basis of the physical property value input through the input device 3, compared with the mastic adhesive 22C not divided into a plurality of parts. The close rigidity is shown, and the user does not need to change the physical property value first input via the input device 3 and perform adjustment of the physical property value.

  FIG. 3E shows a state in which a horizontal (shear direction) load HL (for example, 40 N) is applied from the left side to the upper surface of the plurality of mastic adhesives 22E. When a horizontal load HL is applied to the plurality of divided mastic adhesives 22E, the upper surface of the plurality of divided mastic adhesives 22E is distorted to the right by the deformation amount HD1, as shown in FIG. It becomes the state of the divided mastic adhesive 22F.

  FIG. 3G shows a state in which a horizontal load HL is applied from the left to the upper surface of the mastic adhesive 22G that is not divided into a plurality of parts in the conventional CAE system. When a horizontal load HL is applied to the non-divided mastic adhesive 22G, as shown in FIG. 3 (H), the non-divided mastic adhesive 22G is distorted to the right by the deformation amount HD2. The mastic adhesive 22H is not divided.

  Here, as in the case of the vertical load, each of the solid elements of the mastic adhesive 22E divided into plural pieces and the mastic adhesive 22G not divided into plural pieces have the same physical property value, and the deformation amount is calculated. Therefore, the deformation amount HD1 and the deformation amount HD2 have different values due to the difference in the number of divisions. In the conventional CAE system, it is the same as the case of the vertical load that the physical property values need to be adjusted.

  Next, with reference to FIG. 4 and FIG. 5, the difference in deformation amount will be described using actual analysis results.

  FIG. 4 is a diagram showing how the amount of deformation changes depending on the number of elements after division by applying a load in the compression direction and shear direction to a mastic adhesive having a height of 6 mm, a length of 60 mm, and a width of 60 mm. is there. 4A is a table including a column 40 indicating “the number of elements in the height direction”, a column 41 indicating “deformation amount due to compression”, and a column 42 indicating “deformation amount due to shear”. 4 (B) is a graph in which the horizontal axis indicates “the number of elements in the height direction” and the vertical axis indicates “the amount of deformation due to compression”, and FIG. 4C shows the “elements in the height direction” on the horizontal axis. This is a graph in which “number” and “vertical deformation” are plotted on the vertical axis. Note that the unit of deformation is millimeters, and the “number of elements in the height direction” means, for example, that the number of elements is 3 divided into three in the height direction. Moreover, it is not divided | segmented into the length direction and the width direction.

  As shown in FIGS. 4B and 4C, “the amount of deformation due to compression” and “the amount of deformation due to shear” are substantially constant when the “number of elements in the height direction” is 3 or more, and the number of elements is 1 Compared to the cases of 2 and 2, the rigidity is closer to the actual product. In addition, since the amount of calculation required for the analysis process increases as the number of elements increases, the optimum number of elements as the “number of elements in the height direction” is the minimum number of elements among which the deformation amount is substantially constant. 3 is selected.

  FIG. 4D is a table composed of a column 43 indicating the “number of elements” of the entire mastic adhesive and a column 44 indicating the “deformation amount due to compression”. It is a graph in which “number of elements” and “vertical deformation amount” are plotted on the vertical axis.

  “3” in the second row of column 43 indicates that the number of elements is 3, and means a mastic adhesive that is divided into three in the height direction. “12” in the third row of the column 43 indicates that the number of elements is 12, and means a mastic adhesive that is divided into three parts in the height direction and two parts in the length direction and the width direction. Fixing the height direction to three divisions is based on the analysis result described above. Similarly, for example, “27” in the third row of column 43 means a mastic adhesive that is divided into three parts in the height direction and three parts in the length direction and the width direction. “48” on the line means a mastic adhesive that is divided into three parts in the height direction and four parts in the length direction and the width direction.

  As shown in FIG. 4E, the “deformation amount due to compression” becomes substantially constant when the “number of elements” becomes 27 or more, and the rigidity closer to the actual object than when the “number of elements” is 3 or 12. Will be shown. For this reason, the optimum number of elements as the “number of elements” of the mastic adhesive is 27 (3 divisions in the height direction, 3 in the height direction, and in the length direction and width direction, respectively) while the deformation amount is substantially constant. 3 divisions) is selected. In this case, even when the number of elements is 3 or 12, there is no significant difference in the amount of deformation due to compression, so there may be cases where it may be selected.

  FIG. 5 is a diagram illustrating how the amount of deformation changes depending on the number of divisions when a load in the compression direction and shear direction is applied to a mastic adhesive having a height of 4 mm, a length of 15 mm, and a width of 22 mm. For example, Young's modulus of 0.105, Poisson's ratio of 0.45, and attenuation of 0.188 are applied to each of the solid elements of the mastic adhesive not divided into plural pieces and the solid elements of the plural divided mastic adhesives. Is done.

  FIG. 5A is a table composed of a column 50 indicating “number of elements in the height direction”, a column 51 indicating “deformation amount due to compression”, and a column 52 indicating “deformation amount due to shear”. 5 (B) is a graph in which the horizontal axis represents “the number of elements in the height direction” and the vertical axis represents “the amount of deformation due to compression”, and FIG. 5C shows the “elements in the height direction” on the horizontal axis. This is a graph in which “number” and “vertical deformation” are plotted on the vertical axis.

  Similar to FIG. 4, as shown in FIGS. 5B and 5C, the “deformation amount due to compression” and the “deformation amount due to shear” are approximately when the “number of elements in the height direction” is 3 or more. As compared with the case of the number of elements 1 and 2, the rigidity is closer to the actual object. In addition, since the amount of calculation required for the analysis process increases as the number of elements increases, the optimum number of elements as the “number of elements in the height direction” is the minimum number of elements among which the deformation amount is substantially constant. 3 is selected.

  FIG. 5D is a table composed of a column 53 indicating the “number of elements” of the entire mastic adhesive and a column 54 indicating the “deformation amount due to compression”. FIG. It is a graph in which “number of elements” and “vertical deformation amount” are plotted on the vertical axis.

  Unlike FIG. 4, in FIG. 5E, the “deformation amount due to compression” becomes substantially constant when the “number of elements” becomes 12 or more, and is closer to the real object than when the “number of elements” is 3. It shows rigidity. For this reason, the optimum number of elements as the “number of elements” of the mastic adhesive is 12 which is the minimum number of elements in which the amount of deformation is substantially constant (3 divisions in the height direction, respectively in the length direction and width direction). 2) is selected.

  As described above, based on the analysis results of FIG. 4E and FIG. 5E, the number of solid elements of the divided mastic adhesive is 12 (3 divisions in the height direction) regardless of the dimensions of the mastic adhesive. , Two divisions each in the length direction and the width direction) seems to be optimal.

  Next, a method for generating an analytical model of a mastic adhesive by the CAE system 100 based on the above analysis result will be described below.

  FIG. 6 is a flowchart showing a flow of processing in which the CAE system 100 creates an analysis model of a mastic adhesive.

  First, the CAE system 100 activates the preprocessor 10 and inputs information on the dimensions (height, length, width) and physical property values of the mastic adhesive 22 via the input device 3 and acquires these information. (Information acquisition step of step S1). Next, the CAE system 100 automatically divides the mastic adhesive 22 into three solid elements in the height direction and two solid elements in the length direction and the width direction (element division step in step S2). Finally, the CAE system 100 sets the physical property value of the mastic adhesive inputted via the input device 3 as the physical property value of the solid element of the divided mastic adhesive (information setting step in step S3). The dimensions and physical property values of the mastic adhesive may be stored in the HDD 1 in advance.

  As described above, the CAE system 100 according to the present invention automatically divides the inputted mastic adhesive dimensions into three in the height direction when creating the analysis model of the mastic adhesive. By dividing into two in the width direction, it is possible to express the rigidity close to the real object, and it is possible to eliminate the need to re-input the physical property values or to adjust the physical property values.

  Further, the CAE system 100 according to the present invention can use the physical property value of the mastic adhesive before being divided into a plurality of pieces as the physical property value of each solid element of the mastic adhesive after being divided into a plurality of pieces. Thereby, it is not necessary to input different physical property values before and after the division, and one mastic adhesive is easily managed as having a corresponding one physical property value. Further, by storing and managing physical property values corresponding to each of a plurality of mastic adhesives in the HDD 1 or the like, analysis modeling of the mastic adhesive can be performed easily and quickly.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the number of divisions in the length direction and the number of divisions in the width direction are set to the same number of divisions, but the optimum number of divisions with the number of divisions in the length direction and the number of divisions in the width direction being different. The number may be set in advance.

1 is a schematic block diagram of a CAE system according to the present invention. It is a figure which shows the model of a mastic adhesive agent. It is a figure explaining the deformation | transformation which arises by the load which acts on a mastic adhesive agent. It is a figure (the 1) which shows the analysis result of the deformation | transformation which arises when a load is applied to the mastic adhesive divided | segmented into the some element number. It is a figure (the 2) which shows the analysis result of the deformation | transformation which arises when a load is applied to the mastic adhesive divided | segmented into the some element number. It is a flowchart which shows the flow of the process which creates the analysis model of a mastic adhesive agent.

Explanation of symbols

1 HDD
2 Display 3 Input device 4 CPU
5 RAM
DESCRIPTION OF SYMBOLS 10 Preprocessor 11 Solver 12 Postprocessor 20 1st part 21 2nd part 22, 22A-22H Mastic adhesive 23 Interpolation restraint element 40, 50 The row | line | column which shows the number of elements of a height direction 41, 44, 51, 54 Deformation by compression A column indicating the amount 42, 52 A column indicating the amount of deformation due to shear 43, 53 A column indicating the number of elements 100 CAE system

Claims (2)

In a mastic adhesive modeling method for generating an analytical model of a mastic adhesive in order to perform a finite element analysis of a part including a part bonded by a mastic adhesive,
An information acquisition step of acquiring information about the mastic adhesive;
An element dividing step of dividing the mastic adhesive into a plurality of solid elements;
An information setting step for setting information on the mastic adhesive acquired in the information acquisition step as information on the solid element of the mastic adhesive divided in the element division step;
A mastic adhesive modeling method characterized by comprising: In the information setting step, the information about the mastic adhesive set in each of the solid elements is a physical property value of the mastic adhesive.
The mastic adhesive modeling method according to claim 1.

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