Stochastic Reliability Metholdology for Complex Structures with Uncertainties

本项目拟建立一套随机有限元程序来研究复杂结构的静动力性能，重点研究随机地震荷载作用下薄壳结构的不确定性。考虑了结构的不确定性，如初始几何缺陷、材料特性、边界条件、结构阻尼系数等和随机载荷。主要目标是：(1)将现有的具有确定性缺陷和几何和材料非线性的弯曲四边形薄壳单元的公式扩展到包含随机缺陷和其他结构不确定性；(2)编纂公式，研究几种结构不确定性对静力分析的综合影响；(3)在随机有限元方法和等效线性化技术的框架内，建立了同时考虑空间域和时间随机载荷的几种结构不确定性影响的求解程序；(4)研究地震荷载作用下薄复合结构的动力响应和动力屈曲行为。这一努力将导致具有结构不确定性的实际复杂结构在随机地震荷载作用下可靠性分析的设计方法的发展。

This project is to formulate a stochastic finite element procedure to study the static and dynamic behaviors of complex structures, with emphasis on thin shell structural uncertainties under random earthquake load. Structural uncertainties such as initial geometric imperfections, material properties, boundary conditions, and structural damping coefficients, etc. and random loads are considered. The main objectives are: (1) to extend the formulation of an existing curved quadrilateral thin shell element with deterministic imperfections and geometrical and material nonlinearities to include random imperfections and other structural uncertainties; (2) to codify the formulation to study the combined effects of several structural uncertainties on static analysis; (3) to develop a solution procedure within the framework of stochastic finite element approach and equivalent linearization technique, which simultaneously accounts for the effects of several structural uncertainties in spatial domain and temporal random loadings; (4) to study the dynamic response and dynamic buckling behaviors of thin complex structures subjected to earthquake load. The effort will lead to the development of a design methodology reliability analysis of practical complex structures with structural uncertainties subjected to random earthquake load.