对单层纵边支承单斜杆柱面网壳进行连续倒塌全过程的非线性仿真计算,通过对地震过程中结构构件变形、受力、损伤等参量发展特征的研究分析,提出纵边支承柱面网壳强震条件下的"双斜杆断裂带"连续倒塌模式,并把该模式分为三阶段,阐述了结构连续倒塌全过程的机理.分析了不同地震峰值加速度条件下这三个阶段中结构重心竖向位移的变化特征,在此基础上提出了适用于单层柱面网壳结构的性态水平描述,并建立基于结构重心竖向相对位移的损伤评估指数.
Based on nonlinear simulation of progressive collapse of single-layer cylindrical latticed shell supported by two longitudinal edges, this paper studies the characteristics of deformation, load-bearing and damage development of members and presents a pattern called double fracture-belt through slant rods, that can be divide into three phrases. The mechanism of progressive collapse mechanism is explained in detail. Then, the development of deformation during the three phases is analyzed under different PGA. Thus a new description of behavior level for the kind of shell is set up with a damage assessment index based on relative displacement of gravity.