Research Upon Progressive Collapse Resistance Of Lamella Cylindrical Reticulated Shell Based On Importance Coefficients Of Joints

Many countries have been setting criterions on progressive collapse design due to these failures are happening all over the whole world. But most of the qualitative and quantitative methods are only suitable for the general civil buildings. So a way based on structural robustness are presented in this article to study collapse resistance of high-degree-indeterminacy shells. The main works are as follows:(1) Overview of accidents, criterions and study methods in terms of progressive collapse. Then a method called importance coefficients of joints (ICJ) base on importance coefficients of members (ICM) was put forward.(2) Studying importance coefficients by eigenvalue bulking. Parts of the members or joints are removed according to bulking analysis results. The computation can be reduced by using ICJ method after analysis the ICJ and ICM value. Moreover, the ICJ value is determined by member deformation. As progressive collapse is a complex process, so nonlinear analysis must be used in study the importance coefficients.(3) Study importance coefficients by Newton-Raphson method. The results show that the ICM method have no reference value with progressive collapse design of lamella cylindrical reticulated shell. But the ICJ method is accurate and can reduce computation. The ICM and ICJ value is determined by component stress, which is unlike the results in (2) That is because eigenvalue bulking is a kind of linear-elastic method, so it can’t describe the process of collapse. Therefore, it is nonlinear method that should be utilized to study ICJ.(4) Studying an approach to enhance the resistance capacity of lamella cylindrical reticulated shell. The robustness can be reinforced by controlling accidental load, using rational structural type and changing member size.