Analytical model for the dynamic response of blast-loaded arching masonry walls

The dynamic response of arching masonry walls subjected to blast loads is rather complex and is accompanied by different physical aspects such as: opening/closing of cracks, unloading-reloading effects, and variable arching force magnitude and line of action with time. The longitudinal and lateral inertial forces result in a coupled in-plane/out-of-plane dynamic response. These aspects, which are not considered in present single-degree-of-freedom (SDOF) models for masonry walls simulation, enhances the wall behaviour modelling and make the dynamic analysis complex and challenging. This article presents the development procedure of a new simplified yet realistic SDOF model for the one-way dynamic response of such walls. The model is based on a new recently developed analytical model for calculating the static force-displacement relationship, which is implemented within the equation of motion. Geometric and material nonlinearities, together with loading/unloading paths in the mortar material are considered, and their effect on the dynamic response is investigated. Results of this model were compared with available test results of one-way arching URM walls exposed to blast loads. The model well predicts the maximum peak displacement as well as the overall displacement-time history within the inbound phase. New insights regarding the test specimens and the dynamic characteristics affecting the arching wall behavior are gained.