Analysis of Masonry Wall under Blast Loads using Coupled Lagrangian – Eulerian Method

Abstract

Due to different accidental or intentional events, blast loads have received considerable attention in recent years and have become important service load for some structures. An attempt has been made in this paper for dynamic analysis of 3D brick masonry wall of size 2025 mm x 1800 mm x 102.5 mm under blast loads. Numerical simulation studies to characterize the various structural effects of explosions are presented. A coupled numerical approach using Lagrangian and Eulerian methods is adopted for the incorporation of the essential processes, namely the explosion, shock wave propagation, shock wave-structure interaction and structural response, in the same model. The charge and the air are modeled with Eulerian mesh, while the wall is modeled with Lagrangian mesh. The explicit finite element modelling and analysis are carried out in ANSYS AUTODYN software. The main focus is to evaluate localized damage and global dynamic response of a masonry wall for blast due to a charge of 0.5 kg TNT equivalent at a stand-off distance of 0.5 m from the wall. Two cases are studied such that the charge was kept on the ground and at mid-height of the wall. The analysis results are obtained in terms of velocity, acceleration, pressure and internal energy at critical target points on the wall. The wall was found to experience maximum acceleration is 0.83g and 1.2g for ground blast and air blast, respectively.