A Model for Predicting the Global Response of Reinforced Concrete (RC) Beams Under Blast Loads Considering Shear and Flexure Modes

In recent decades, the response of structures to blast loads has garnered increasing attention. More specifically, using Reinforced Concrete (RC) for the structural elements is very common in protective structures and therefore, the prediction of their dynamic response is of interest. To assess the resistance of RC structural elements to blast loads, the response is commonly assumed to be governed by flexure mode, and the maximum displacement and parameters like the support rotation and ductility ratio are used to evaluate the level of damage of the element. In some cases, especially in relatively stiff elements, shear deformation may influence the dynamic response and the failure modes. This study presents a formulation for the response of RC members under blast, by considering nonlinear constitutive laws and deformations in both flexure and shear. The model is based on solving nonlinear equations based on Timoshenko’s beam theory using a dedicated numerical algorithm. The algorithm considers the finite difference method in space and Newmark’s beta time-step method in time. Also, the model considers the strain rate effects in a dedicated, fast-running, and detailed approach. The paper discusses the concept of the model and a comparison with experimental data is presented.