Energy Absorption Performance Of Empty And Polyurethane Foam-filled Connectors

Blast-related threats to paramount architectures are surging with a high degree and thus,their safety has become a topic of lofty importance.The research community has been focusing on developing energy absorption structures to protect buildings from the blast load.Despite many studies already been performed to design blast resistant structures,there is still a high research demand of energy absorption connectors that can be placed between the blast-resistant fa?ade and load bearing members of the structure.In this study,energy absorption connectors capable of dissipating blast energy and decreasing peak force transferred to the load bearing members have been proposed.Those empty or polyurethane foam-filled energy absorption connectors possess advanced geometric shapes.Besides being used for energy absorption purposes,proposed connectors also have the potential of being applied to improve the crashworthiness of the vehicles for passengers' safety during a vehicle collision.First of all,Quasi-static compression tests of the connectors were performed experimentally.The numerical models for quasi-static compression of the connectors were developed using explicit LS-DYNA finite element codes.Then,the connectors were experimentally tested under dynamic compression.Numerical models for simulating dynamic compression were also developed using explicit LS-DYNA finite element codes.The failure mechanisms and energy absorption parameters of the devised connectors were evaluated for both cases of compression.The results revealed that polyurethane foam filling,increasing thickness of the armed plates and decreasing height from the top of the armed plate to the intersecting point of the two arms improved energy absorption characteristics of the connectors.The comparison of quasistatic and dynamic compressions diagnosed that dynamic compression(with a highest impacting velocity of 13 m/s)had a similar failure mechanism to that of quasi-static compression,but with higher values of energy absorption parameters.The developed numerical models for quasi-static and dynamic simulations were validated with reference to the experimental results.The numerical and experimental outcomes matched each other with acceptable accuracy.This indicated the non-linearity in both material and geometry of the connectors can be simulated precisely by those finite element models along with providing the complex failure mechanism reliably.The numerical models can also be used to do an in-depth study of the connectors' characteristics which cannot be done accurately from the experimental study related to energy absorption characteristics of the connectors.