Combined Blast and Fragments Loading of Explosively Welded Plates

Abstract

The paper presents the results of a experimental and numerical investigation into the deformation and failure mechanisms of explosively welded steel/titanium plates (EWP) subjected to combined blast and fragment loading - an area with limited prior exploration. Close-in blast tests were conducted using TNT charges embedded with tungsten ball bearings to replicate realistic multi-threat scenarios. The performance of EWP was directly compared to that of monolithic steel plates of equivalent mass. The results demonstrated that EWP exhibited significantly reduced deflection and damage, highlighting its superior resistance to combined loading. A validated numerical model was developed, in LS-Dyna, to capture the complex interaction between blast and fragments loading and the subsequent structural response. The simulations, together with analytical closed-form solutions, provided insights into key mechanisms contributing to the enhanced performance of EWP, including the influence of blast-induced projectile deformation, target/projectile relative motion and elevated strength from membrane action. These findings underscore the synergistic effects of combined loads and the critical role of loading sequence. This study provides new understanding of EWP behaviour under multi-modal threats and establishes its practical potential for lightweight, high-performance protective structures for critical infrastructure applications.

Keywords: Combined loading, Explosive welding plates, large deformation, Ductile fracture, Synergistic effect