Experimental investigations and numerical simulations of multi-arch double-layered panels under uniform impulsive loadings

Abstract

A double-layered panel with a structural form of multi-arch-surface has recently been numerically demonstrated capable of absorbing considerable energy and mitigating the blast loading effects on structures. In this study, experimental tests were conducted to further verify the performance of multi-arch double-layered panels subjected to uniform impulsive loadings by using a pendulum impact test system at the University of Western Australia (UWA) Structural Lab. The uniform impulsive loadings were generated by pendulum striking on the surface of a fully confined airbag placed in front of the specimen. Specimens with various configurations were designed and tested to investigate the effects of different configurations, i.e. arch height, arch number, thickness and different loadings on the structural response to the uniform impulsive loads. Single-layered flat steel panels were also tested as control panel for comparison to study the efficiency of double-layered multi-arch panel in resisting impulsive loads. The experimental data including air pressure time history acting on the front arched layer, displacement time history at the center point on the back flat layer and strain history at some representative points on the back flat layer were recorded. The deformation modes of specimens are also identified and discussed. The experimental data show that the multi-arch panel with specific configuration performs better than the flat monolithic panel in resisting uniform impulsive loadings. Numerical models were also developed to simulate the experimental tests by using finite element codes Ls-Dyna. The predicted data from the numerical simulations were compared with the experimental results. A good agreement between the experimental and numerical results was achieved. The responses of peak boundary reaction forces were extracted from numerical results to further examine the effectiveness of multi-arch panels against uniform impulsive loadings. The validated numerical model can be used to conduct intensively numerical simulations to define the best performing multi-arch panel configurations for blast loading resistance.