基于应变响应敏感性的单层球面网壳冗余度分析

摘要

Redundancy is an important part of structural robustness .It reflects the safety of complex sys-tem and the reliability of the force transmission path .Nevertheless ,it should be remarked that there is ,as yet ,neither a uniform theory of structural redundancy nor any widely agreed definitions in structural en-gineering .In this paper ,the P .C .Pandey method is referenced and applied to long-span space latticed structure .A method ,in w hich the derivation of element strain to the cross-sectional area of elements is taken as the response sensitivity ,is proposed based on the response sensitivity to assess the redundancy of structure under static load .It is illustrated that the method can be applied in space structure effectively via three examples .Numerical results show that the redundancy can reflect the importance of structural component .Structural elements with low redundancies are the key components of the structure .Taking measures to reinforce the components with small redundancies can efficiently improve both the whole stiffness and the ultimate bearing capacity of the structure ,w hile it depends on the concrete situation w hether the imperfection sensitivity is ameliorated .%冗余特性是结构鲁棒性的重要组成部分，也是复杂系统的安全性和传力路径可靠性的体现。如何对结构构件冗余度进行定量评价是目前结构工程界尚未定论的问题之一。本文借鉴P ．C ．Pandey方法，并将其推广应用到大跨空间网格结构，基于结构应变响应对构件单元截面面积的敏感性提出静力作用下的结构构件冗余度评价方法，从理论上以数值方式量化结构构件冗余度，并通过对三个球壳结构算例的冗余度分析说明该方法在空间结构体系中的有效应用。算例结果表明，结构构件冗余度能够反映构件在结构中的重要性，低冗余度构件是结构的关键构件。采取措施加固低冗余度构件可以有效提高结构整体刚度、结构稳定极限承载力，但在改善结构缺陷敏感性方面则视具体情况而定。