Modified Quasi-Static, Elastic-Plastic Analysis for Blast Walls with Partially Fixed Support

Blast walls with partially fixed support have been used to limit impacts of pressure due to an explosion. As design criteria, the dynamic response of blast wall systems in terms of their pressure load-displacement relationship is considered. In addition to a complicatedly dynamic analysis, the quasi-static, elastic-plastic analysis is recently an alternative method. However, the pressure load-displacement response of the system with the short connection obtained from the quasi-static, elastic-plastic analysis tends to be over conservative comparing with the response of the previous experiments. Therefore, the quasi-static, elastic-plastic model is modified to improve the prediction accuracy. The model simply consists of two flexural elements connected through an angular spring element. The beam end is supported by the vertical and horizontal spring. The horizontal spring is simulated based on a cantilever beam mechanism and an axial restraint of the connection member. The uncoupled displacement mode shapes are assumed to represent the overall elastic-plastic behavior of the systems. The quasi-static equilibrium equations are determined from the minimum potential energy of the system. The predicted response of the modified analysis is found to better agree with the previous experimental response of the systems with the short connection.