An experimental study of the effects of degrees of confinement on the response of thermoplastic fibre–metal laminates subjected to blast loading

Abstract

A series of tests on the dynamic response of thermoplastic fibre–metal laminates (TFMLs) subjected to blast loading with three different degrees of confinement (unconfined, vented and fully confined) were performed. The deflection time histories, the residual deformation, the internal delamination and damage mode of the TFMLs were recorded or observed by employing the digital image correlation, the 3D scanning and X-ray computed tomography techniques. Based on equivalent material properties combined with dimensionless damage numbers φq, the deformation of fibre–metal hybrid structures of different configurations can be effectively predicted and verified by experimental data. In addition, the effective load applied to the hybrid structure within the saturation response time is a key factor in determining the blast performance at different degrees of confinement. Vented explosions can result in the same dynamic response as fully confined explosions with even more severe internal delamination. The presence of quasi-static pressure in fully confined explosions can contribute more than 20% to the final deformation. The results can provide a basis for further understanding of the dynamic response and failure behaviour of fibre–metal hybrid structures subjected to blast loading with different degrees of confinement.