PROGRESSIVE COLLAPSE ANALYSIS OF 2-D RC FRAMES USING AEM

Abstract

Numerical simulation of a progressive collapse of structures using computer has a very actual apprehension for structural engineers due to their interest in structures veracity estimation. This simulation helps engineers to develop methods for increasing or decreasing the progressive failure. Finite Element Method (FEM) is the most computer simulation analysis currently used to perform a structural vulnerability assessment. Unfortunately, FEM is not able to automatically analyze a structure after element separation and collision which has a great effect on a structure’s performance during collapse. For instances, a bombing load can cause damage to a main supporting column in a structure, which will cause debris flying at a very high velocity from the damaged column. This debris can cause another local failure in another column upon impact and lead to the progressive collapse of the whole structure. A new simulation technique, which was developed in 1995 as part of Tagel-Din’s doctoral research, called Applied Element Method (AEM) can simulate the structure’s behaviour from zero loading until collapse, through the elastic phase, opening and propagation of cracks, yielding of reinforcement bars and separation and collision of elements. This method is used in Extreme Loading for Structures software (ELS) by Applied Science International (ASI). In the current paper, a brief description of the AEM is given. Also, numerical modelling based on two experimental studies available in the literature conducted by Ahmadi et al. and Yi et al. are generated using ELS. These models are used to confirm the capability of AEM in simulation the progressive collapse behaviour of structures. Also, the models are utilized to examine and measure the structural resisting mechanisms of reinforced concrete structures against progressive collapse. The obtained numerical results indicated that, ELS can accurately model all structural behaviour stages up to collapse. A better agreement between the experimental and numerical results is observed. Moreover, the results obtained with ELS indicated an enhanced agreement with other software packages such as; OpenSees, Ansys, Abacus, and MSC Marc.

Keywords

• Progressive collapse
• Reinforced concrete frames
• Applied element method
• Extreme loading for structures
• Displacement control