Preventing progressive collapse through strengthening beam-to-column connection, Part 2: Finite element analysis

This two-part paper presents part of the results of a study devoted to the investigation of retrofitting effect of simple steel construction. Through strengthening simple beam-to-column connection, progressive collapse can be prevented by catenary action. The evaluation of catenary action represents a complex analytical problem with a large tension affecting its structural behavior. With the advent of high speed computers and powerful calculation software package, the finite element method offers an ideal tool for tackling such a complex problem. This paper develops sophisticated one-, two- and three-dimensional models of catenary action, and simulates the post-attack behavior of the original and the strengthened structures by means of the ABAQUS finite element package. The global behavior of the one-dimensional beam element model is close to that corresponding to the two-dimensional solid or the three-dimensional shell models, particularly for the structures with strengthened joints. Comparison of results between this study and literature has been carried out for the purpose of validating the present finite element prediction model. Through the comparing computational results before and after strengthening, the advantages of proposed retrofitting scheme are demonstrated.