One of the biggest deficiencies of most current structural design codes is that they do not necessitate performing a progressive collapse analysis of a building. The catastrophic result of this deficiency is that many existing buildings may collapse totally or partially due to the failure of just one column under the effect of man-made or natural disasters. One of the sad examples is the collapse of almost 40% of the Alfred P. Murrah Building at Oklahoma City due to a terrorist attack that affected one of its columns.

Currently, design codes all over the world are being modified to have mandatory checks of buildings against progressive collapse. Simulation of progressive collapse of a structure is one of the most complicated engineering tasks. Accurate analysis should consider numerous factors, including nonlinear behavior of concrete and steel, accurate failure criteria, automated criteria for element separation, and collision between falling debris and other structural elements.

The question which arises for many engineers is “Which structural analysis tool can we use to study progressive collapse?”

Applied Element Method is a new concept in structural analysis that is designed mainly for engineers to do advanced analysis that is usually done by scientists. Using the AEM, the progressive collapse analysis can incorporate crack initiation and propagation, yield of steel, buckling and post-buckling behavior of columns, element separation, falling of debris, and collision between different structural elements. The analysis can be completed in reasonable time, with reliable accuracy and without any user intervention or pre-conditioning to control the way the building should behave under extreme loadings.