R/C Structures Under Impulsive Loading

Abstract

A finite element method is presented to analyze the effects of airblast‐induced ground shock on shallow‐buried, flat‐roofed, reinforced concrete structures. A finite element based on Timoshenko beam theory is adopted. Material properties are defined in terms of nonlinear stress‐strain relations in each of several layers through the thickness of the element. Elastic, ideally‐plastic constitutive properties for plain concrete are cast in terms of shear‐stress/normal‐stress variables. Elastic, strain‐hardening constitutive properties are assumed for steel. Dynamic explicit and implicit and static solution algorithms are available. General two‐dimensional structures, such as rings and arches as well as boxes, can be represented. This analysis method is applied to simulation of static beam‐column tests reported by ACI Committee 318‐77. It is then applied to simulation of structural response in FOAM HEST Events 2, 3 and 4 in which shear, flexure and combined shear‐flexure damage was observed. In these post‐test simulations, measured interface stress‐time histories are used as input.