A modal nonlinear static analysis method for assessment of structures under blast loading

Abstract

Modal pushover analysis (MPA) has been developed in previous studies to analyze the response of structures subjected to seismic excitation. Although this method has already been extended for diverse systems of buildings and bridges, its application is currently restricted to earthquake loading. This study is intended to extend this approach for the analysis of structures subjected to other probable loading patterns, such as blast waves and wind loads. For the analysis of structures under seismic excitation, an acceleration is applied to the structure’s base; however, in the case of a blast wave or wind load, the external load is directly applied to the building with an unexpected load pattern. Based on these differences, a new formulation for the modal analysis of structures is developed in this study. To evaluate the method, a shear wall structure is used as a case study, and the impact of a blast wave is considered as an imposed lateral load. The results obtained by the proposed method, called MPA-B, are compared to those of nonlinear dynamic analysis as a benchmark solution. The structural demands that are used as the comparison criteria are story displacement, story drifts and hinge rotations. The results of this evaluation show that the accuracy of the MPA-B method in the analysis of structures under a blast load is similar to the accuracy of the MPA method in the analysis of structures under earthquake loading.