结构仿真高精度有限元网格划分方法

Meshing Method of High Precision FEM in Structural Simulations

为了得到高精度计算结果的有限元网格,在有限元模型任一单元小片内将其误差分解为全局误差与局部误差两部分:局部误差是由于该单元小片内单元的残值所引起的,而全局误差是由单元小片外区域内单元的残值所导致。提出关键性区域的概念,并得出有限元求解模型中所有关键性区域的网格划分水平决定整个有限元模型的计算结果精度的论断。基于该结论建立高精度有限元网格划分方法流程。以连杆为实例,应用高精度有限元网格划分方法流程对连杆进行高精度网格划分。在压缩工况下,对其平面模型进行关键性区域的划分,并研究其误差特性,可知局部误差是连杆结构仿真误差的主导部分。划分疏密得当的高精度网格。应用实例证明了提出方法的可行性、实用性。

In order to obtain the finite element network from the result of high precision calculation, the error in any patch of the finite element is split into two components： the local error and global error, the former is caused by the residual value of element in the element patch, while the latter is caused by the residual value of element in the external area of the element patch. The concept of key areas is put forward, and it is concluded that the precision of calculation result of the whole finite element model is determined by the meshing level of all the key areas in the finite element model. Based on this conclusion, the meshing flowchart of high precision FEM is established. Taking the connecting-rod as example, it is meshed by using the method of above flowchart. Under the compression work condition, the key areas of connecting-rod plane model are figured out, and its error property is studied. The high precision meshing grids are obtained. Feasibility and practicability of the method are proved.