Finite Element Collapse Analysis of Framed Structures by the Shifted Integration Technique

The present study is concerned with the finite element collapse analysis of framed structures by using the shifted integration technique, in which the locations of plastic hinge formation are controlled by the movement of numerical integration points in each finite element. Theoretical basis of the shifted integration technique is described with some numerical illustrations for a simple beam. The refined version of the shifted integration technique, in which the adaptive shifting of integration points is conducted, is introduced and applied to the plastic collapse problem of a simple space frame. The shifted integration technique is also applied to the crush analysis of three-dimensional framed structures under quasi-static loading, which is based on the incremental theory by the updated Lagrangian Jaumann stress rate formulation employing the resultant forces and considering the strain hardening and the frictional contact. The calculated finite element solutions are compared with the results of the crush tests conducted by the authors.