Discrete element method-based collapse simulation,validation and application to frame structures

A discrete element model (DEM) is proposed herein for the collapse analysis of reinforced concrete (RC) frame structures, which is based on the improved segment-multi-spring model (SMSM). Failure criteria of the springs between elements are well established and the coupling effects between them are considered, while a methodology that can assess the global angular displacement of discrete element is developed. Moreover, a new modified element contact detection algorithm is also provided to improve computing efficiency and accuracy after elements fail. Accordingly, a DEM-based software is developed for the collapse simulation of RC frame structures utilising SMSM. Its accuracy and reliability are validated through a simulation of an experiment in which a frame structure collapsed due to the failure of a middle bottom column. Subsequently, a further investigation on the overall collapse process of the examined frame is performed. Simulation results agree well with experimental results. Finally, the software is applied to analyse a real building destroyed by the Wenchuan earthquake and the results show a good agreement with the in situ earthquake damage investigation.