Enhanced Modeling of Steel Structures for Progressive Collapse Analysis Using the Applied Element Method

Abstract

This paper studies performing progressive collapse analysis for steel structures using the requirements of recent codes released by the U.S. Department of Defense and the General Services Administration. Based on a review of the code requirements, the nonlinear dynamic progressive collapse analysis resulted in a more uniform factor of safety than the linear static analysis. The applied element method in the structural analysis is proposed as an efficient alternative for performing progressive collapse analysis. A case study is undertaken where the results of the progressive collapse analysis using traditional finite-element-method simplifications are compared with the results from the applied element method in the analysis of a moment-resisting steel frame. The case study shows that simplifications that are usually done in finite-element analysis when studying traditional load cases can be overconservative when performing progressive collapse analysis. The results show that the use of the nonlinear dynamic applied element method, while taking into account the effect of secondary members such as slabs and secondary beams, can lead to considerable savings in the total weight of the steel frame.