Tetrahedral mesh generating method for finite-element analysis and finite-element analyzing system using its method

Abstract

A finite-element analyzing system executable by a computer includes an analyzing-condition setting unit that captures data on a solid model of a product and sets an analyzing condition, a high-density tetrahedral mesh generating unit that captures the solid model and the analyzing condition and adds an identification sign to an element, to which the analyzing condition is set, based on at least a setting element size, thereby generating a tetrahedral mesh with high density, a multi-resolution tetrahedral mesh generating unit that captures the tetrahedral mesh which is generated by the tetrahedral mesh generating unit and additionally has the identification sign, and a finite-element analyzing unit 4 that captures the tetrahedral mesh with multi-resolution which controls the resolution generated by the multi-resolution tetrahedral mesh generating unit and performs the finite-element analysis by using the analyzing condition.

1 . A tetrahedral mesh generating method for finite-element analysis executable by a computer, comprising: 
 a first step of adding an identification sign to an element, to which an analyzing condition of a solid model of a product is set, and of generating a tetrahedral mesh of said product; and    a second step of performing simplification for storing said element for setting the analyzing condition and reducing the number of tetrahedral meshes generated by said first step and generating the tetrahedral mesh for finite-element analysis.    
   
   
       2 . A tetrahedral mesh generating method for finite-element analysis according to  claim 1 , further comprising: 
 a third step of executing the finite-element analysis based on said analyzing condition set as the tetrahedral mesh for finite-element analysis generated by said second step.    
   
   
       3 . A tetrahedral mesh generating method for finite-element analysis according to  claim 1  or  2 , wherein said second step calculates a new vertex for integrating vertexes at both end points of a ridge line forming the tetrahedral mesh to one, and performs said simplification based on said calculated new vertex.  
   
   
       4 . A tetrahedral mesh generating method for finite-element analysis according to  claim 3 , wherein said processing for calculating the new vertex executes the processing while storing the mesh element to which the analyzing condition is set.  
   
   
       5 . A tetrahedral mesh generating method for finite-element analysis according to  claim 4 , wherein said processing for calculating the new vertex does not execute said simplification, when said ridge line is a ridge line to which said analyzing condition is set or when the end point of the ridge line is a vertex or end point to which said analyzing condition is set.  
   
   
       6 . A tetrahedral mesh generating method for finite-element analysis according to  claim 3 , wherein said simplification in said second step reduces the number of said meshes under a condition to satisfy a parameter for controlling the characteristics of mesh which is preset, and 
 said tetrahedral mesh generating method for finite-element analysis further comprises: a fourth step of correcting said parameter based on an analyzing result executed by said third step.    
   
   
       7 . A tetrahedral mesh generating method for finite-element analysis according to  claim 4 , wherein said simplification in said second step reduces the number of said meshes under a condition to satisfy a parameter for controlling the characteristics of mesh which is preset, and 
 said tetrahedral mesh generating method for finite-element analysis further comprises: a fourth step of correcting said parameter based on an analyzing result executed by said third step.    
   
   
       8 . A tetrahedral mesh generating method for finite-element analysis according to  claim 5 , wherein said simplification in said second step reduces the number of said meshes under a condition to satisfy a parameter for controlling the characteristics of mesh which is preset, and 
 said tetrahedral mesh generating method for finite-element analysis further comprises: a fourth step of correcting said parameter based on an analyzing result executed by said third step.    
   
   
       9 . A generating method of tetrahedral mesh for finite-element analysis according to  claim 5 , wherein said parameter for controlling the characteristics of mesh is at least one of a lower limit τ ST  of the quality of element shape, an upper limit τ SZ , of the size, an upper limit τ SL  of an approximation error for shape, and an upper limit τ VL  for vertex estimation.  
   
   
       10 . A finite-element analyzing system executable by a computer, comprising: 
 an analyzing-condition setting unit that captures data on a solid model of a product and sets an analyzing condition;    a tetrahedral mesh generating unit that captures said analyzing condition and said solid model and adds an identification sign to an element, to which the analyzing condition is set, based on at least a setting element size, to generate a tetrahedral mesh;    a multi-resolution tetrahedral mesh generating unit that captures the tetrahedral mesh which is generated by said tetrahedral mesh generating unit and additionally has said identification sign and generates the tetrahedral mesh for analyzing with low density; and    a finite-element analyzing unit that captures the tetrahedral mesh of multi-resolution for controlling the resolution generated by said multi-resolution tetrahedral mesh generating unit and performs the finite-element analysis by using said analyzing condition.    
   
   
       11 . A finite-element analyzing system according to  claim 10 , further comprising: 
 a parameter changing unit that changes said characteristic control parameter of the mesh based on the analyzing result of said finite-element analyzing unit.