Predicting the response of locally resonant concrete structure under blast load

Abstract

Ternary locally resonant metamaterial (LRM) is a manmade material consisting of rigorously designed heavy inclusions with coated soft layer. Such design enables the LRM to possess good wave-filtering characteristics that differ from the matrix materials. Researches of application of this new material for seismic isolation and sound insulation in civil engineering have been reported. In recent decades, there has been an increasing demand to protect civil engineering structures against the effects of blast loading. When blast wave acts on a concrete structure, complex stress waves are generated and propagate in the structure. The wave-filtering characteristics of LRM have brought inspiration to investigate its potential application to reduce the stress wave propagation and hence the damage to cementitious material and enhance the performance of structures under blast wave. By embedding heavy inclusions with soft coating layer into mortar matrix, the product can be named as ternary locally resonant concrete (ternary LRC). Previous studies of the performances of ternary LRC structures are mainly limited to finite element (FE) modeling of elastic wave propagation. The study of the performance of ternary LRC structure subjected to blast loading and the influence of blast loading-induced damage to LRC structure on stress wave propagation is very limited. This paper carries out analytical derivation and numerical modelling to study the mechanism and performance of ternary LRC structure under blast loading. The strain rate effect and material damage of the mortar matrix are considered in numerical simulation. The influence of different material inclusions (natural aggregates and lead), different elastic modulus and thickness of the soft coating on the response of ternary LRC structure are studied. The results show that the ternary LRC can effectively reduce the damage of ternary LRC structure subjected to blast loading.