CONTROL OF DYNAMIC COLLAPSE MECHANISM OF DOUBLE LAYER TRUSS WALLS SUBJECTED TO EARTHQUAKE MOTION

Abstract

 This study deals with the dynamic elasto-plastic analysis considering a member buckling and the fuse type connection composed of of an aluminum hub and a steel bolt. A ductile elongation of the steel bolt due to a tensile stress is expected by avoiding the brittle collapse in our previous paper⁵⁾. The study proposes a fuse type connection by means of yield of the steel bolt due to a tension stress realize the ductile failure collapse mechanism of the wall type spatial structure.
 The seismic response characteristics of spatial structures such as roof and wall types depend on their form and support conditions. Several reviews and guidelines quoting many studies have been published depending on the performance of building structures. Several performance prediction methods have been developed for this purpose, however, the earthquake resistance capacity of spatial structures requires the variation of the form and the support condition. On the other hand, it is very difficult to apply them to wall type spatial structures. For the performance design, several prediction methods such as a pushover analysis and an adaptive capacity spectrum method have been developed for structures such as buildings and bridges.
 The control of the dynamic collapse mechanism is also proposed to improve the earthquake resistant capacity by the fuse type connection using the steel bolt elongation.
 Effect of the member buckling and yield elongation of the steel bolt on the seismic response of the out of the plane is shown in comparison with response of the wall structure subjected to the horizontal earthquake motions. The earthquake evaluation method is also proposed considering the dynamic collapse mechanism. A validity of the proposed method is shown by means of the accuracy between the analysis and the estimation.
 The study deals with the partial cylindrical truss wall with the fuse type joint connection subjected to horizontal earthquake motions. It is confirmed in the dynamic elasto-plastic analysis that the control of the dynamic collapse mechanism such as the steel bolt elongation can avoid a brittle collapse mechanism such as a chain of the member buckling. The behavior due to the member buckling and yield elongation of the steel bolt is shown in the dynamic response of the wall structure subjected to horizontal earthquake motions.
 The evaluation method is also proposed by means of the limit displacement considering a ductility factor of the steel bolt within 4. This means that the response control can be feasible by the damper connection such as the steel bolt elongation due to a tension stress.