受非平稳地震作用的密肋复合墙体的可靠度分析

Reliability Evaluation of Multi-Ribbed Composite Wall Subjected to Non-Stationary Random Earthquake

通过数值计算对受非平稳随机地震作用的密肋复合墙体的动力可靠度进行分析.首先将随机地震动模型表示为均匀调制的非平稳地震动模型,通过振型叠加法求出随机地震反应的功率谱密度和均方值;其次应用首次超越破坏准则给出结构随机地震反应动力可靠度的具体计算公式,并给出结构在弹塑性状态时的界限值;最后对有限元建模时视为实体模型的单层密肋复合墙体与同模型尺寸的框架和剪力墙的动力可靠度进行了计算,对比分析了3种结构在多遇地震和罕遇地震作用下的动力可靠度.结果表明,密肋复合墙体的动力可靠度介于框架与剪力墙之间,密肋壁板结构是一种安全可靠的新型结构.

The objective of the present work is to evaluate the integrated reliability of multi-ribbed composite wall subjected to random earthquake. The non-stationary stochastic earthquake is described by an envelope-modulated stationary random process. The stochastic dynamic analysis is performed by using modal superposition method to obtain the power spectral density function of random response. Then mean square values are obtained based on computed random response. The detailed reliability formulation is developed through the solution of first passage problem. The limit value of inelastic state is equivalent to linear value. Multi-ribbed composite wall of one floor, frame and shear wall of the same size as the composite wall, idealized as solid models in finite element modeling, are considered for relia- bility analysis. Dynamic reliability of the above three structures under effect of frequent earthquake and rare earthquake are compared. Results show that the dynamic reliability of multi-ribbed composite wall is between the reliability of frame and the reliability of shear wall, and the multi-ribbed slab structure is a safe new structure.