유한요소해석을 이용한 SPFC 780 판재의 충격 특성 연구

The objective of this paper is to investigate the influence of impact conditions on the impact characteristics of the SPFC 780 sheet for the case of the free boundary conditions. In order to examine impact characteristics of the sheet, three-dimensional finite element analyses have been performed. High speed tensile tests have been carried out to obtain strain-stress relationships including the effects of the strain rate. Through the comparison of the results of FE analyses and that of impact tests, an accurate FE model has been developed. In order to reduce error range of load and displacement, the hyper-elastic model and the damping factor have been employed. From the results of FE analyses, the variation of stress and strain energy in the SPFC 780 sheet has been quantitatively examined.