Investigation of effect of negative phase of blast loading on cable net curtain walls through the linearized stiffness matrix method

摘要

Safety of cable net structures has been threatened due to rising conflicts and the possibility of exposure to blast load. Pre-tensioned cable nets are geometrically nonlinear problems and the nonlinearity can be addressed by using the linearized stiffness matrix method (LSM). On the other hand, the effect of negative phase pressure of blast wave is usually ignored in practice while the research indicates its significance on the dynamic response of the system. In this paper, LSM method is used to study the effect of negative phase pressure and other factors such as charge weight, standoff distance, pretension level, and modal frequency on cable net structures. The effect of glass panel failure on the system response is also studied by removing the corresponding wave pressure acting on the failed glass panels. Accuracy of the LSM method is evaluated through comparison between the proposed numerical and closed-form solution. The results indicate the significance of the effect of negative phase pressure on the system response, which is pronounced at lower TNT weights and more flexible structures. The major effect of negative phase pressure is on the outward displacements, which exhibits up to 25% more displacements for the studied cable net when the negative phase pressure is considered. Failure of glass panels and consequent pressure release in negative phase can cause increase in the subsequent displacements. LSM method can reliably predict the system response as far as displacements are not too large. However, at very large displacements, LSM method significantly overestimates the predicted displacements.