Experiment on beam-truss structure model by introducing incipient failure in collapse

Abstract:

Experiments on structural progressive collapse were carried out to truss-beam in three dimensional system model. A manually controlled apparatus inducing initial member failure was developed, which can be easily installed as part of structural members subjected axial forces. By using non-contact digital image processing technique and high frequency strain acquisition system, the displacements and strains occurred during the dynamic process after initial member failure could be obtained. The duration of collapse process, displacement and strain history at the measuring spots were analyzed to reveal the collapse mechanism. The results show that the margin of loading capacity of members over their inner forces induced by vertical loads and the interaction of structural components in the three dimensional system provide main redundancy against progressive collapse. Simple model analysis and non-linear dynamic numerical simulation were also performed to explain the behavior of failure process.