Research On Contact Search Algorithm And Software Development Based On SiPESC.FEM

Contact-impact problems exist widely in various practical engineering problems,such as automobile collision,sheet metal forming,mobile phone falling and so on.Because of the high experimental cost of this kind of problems,explicit finite element method is often used in the design of modern industrial products.At present,foreign countries are in absolute monopoly in the field of commercial explicit finite element,such as ABAQUS-Explicit and LS-DYNA.In the face of foreign technology blocking of China's high-end industries,it is urgent to develop independent and controllable explicit finite element software.One of the cores of explicit finite element solution is contact calculation,and the most important thing in contact calculation is contact search.In the actual engineering simulation,the calculation time of contact search accounts for one third or even more than half of the whole analysis.At the same time,the calculation accuracy of contact force depends on accurate contact search.Therefore,the contact search algorithm is very important for the overall efficiency and accuracy of the explicit finite element method.In this paper,we focus on the contact search algorithm and implement it on the framework of SiPESC explicit finite element methodNode to surface search algorithm: This paper introduces the fast global search algorithm based on "node search node" and the corresponding data storage structure,the fast global search algorithm based on "node search segment" and the corresponding data storage structure,and discusses the computational efficiency and application of the two global search algorithms;The calculation methods of contact information such as contact point,penetration and slip in local search algorithm are introduced.The global search algorithm and local search algorithm of the point surface search algorithm are implemented on the framework of SiPESC explicit finite element method.For a series of typical examples,the correctness of the program is verified by comparing the calculation results with the NTS algorithm of LS-DYNA.Single surface self-contact search algorithm: the related problems of self-contact search algorithm are discussed;The fast global search algorithm based on "segment search node" and the corresponding data storage structure are introduced;In the self-contact local search algorithm,the processing of shell thickness and the judgment criterion of penetration direction are introduced.The single-sided self-contact search algorithm is implemented on the framework of SiPESC explicit finite element method.For a series of typical examples,the correctness of the program is verified by comparing with the results of the ASSC algorithm of LS-DYNA.Automatic contact search algorithm is used to deal with the contact problem between multiple parts.A surface mesh extraction tool is developed to extract the outer surface mesh of the model for contact calculation.For a series of typical examples,the correctness of the program is verified by comparing the calculation results with the Ag algorithm of LS-DYNA.