Assessment of energy redistribution of structural collapse under seismic loads using wavelet transforms

Damages due to complex loading or under natural disasters may cause progressive collapse (PC) in structures have not received much attention despite the importance of the potentially catastrophic impact of these types of deteriorations. When a structure is exposed to external excitations, an energy flow in the structural components is accumulated and stored depending on the effective stiffness of these components. Any modification in the material properties, connections between components, or structural continuity would modify the effective stiffness, thus leads to the energy distribution variation in structural components. Once a member fails the load supported by the lost member is redistributed to the adjacent structural members. If these members are incapable of withstanding the additional loading, they continue to fail and that gives rise to damage and may result in a PC. The objective of this study is to use continuous wavelet transform (CWT) to study the consequences of the PC distribution trend and the energy redistribution after one of the structural members is lost due to external loading event. An efficient strategy based on various scenarios is developed and used via a robust finite element computational tool to model and simulate the damage in order to capture the structural vibration responses. Nonlinear static and dynamic analyses are used using Abaqus and CWT are used for investigation purposes. The results show proper and effective analysis of the structures having high potential to PC.