금속 성형 공정의 준정적 변형 예측을 위한 외연적 시간 적분 유한 요소법의 적용성 연구

Abstract

In the analysis of metal forming problems, the explicit time integration finite element method, which does not have convergence problems, is frequently used. The present work is to assess the applicability of the explicit time integration finite element method to quasi-static metal forming problems, Compression analyses of thin-walled tubes and solid cylinders are performed with different landing velocities. The computed buckled profiles of thin walled tubes are compared with the theoretical and experimental ones and it is found that at sufficiently low loading velocity. the explicit time integration finite element method accurately predict quasi-static buckled profiles. When loading velocity is increased, the computed buckled profiles of thin-walled tubes are very sensitive to loading velocity, however. the computed profiles of solid cylinders are less sensitive to loading velocity. In other words, the geometrically self-constrained specimens like solid cylinders are less sensitive to loading velocity than the geometrically unconstrained specimens like thin-walled tubes. As a result. it is found that the geometrically self-constrained problems which include the greater part of metal forming problems can be efficiently analyzed with loading velocity control technique.