工程结构鲁棒性定量分析

Quantitative robustness analysis of engineering structures

工程结构的鲁棒性是指结构遭受突发的局部损伤而不至发生不成比例破坏的能力。提高结构的鲁棒性已被视为确保结构安全性不可或缺的措施之一,与增加构件的安全储备和加强施工的安全监督同等重要。鲁棒性定量分析的目的就是为了量化结构系统的这种能力,并找出结构内部"牵一发而动全身"的致命部位。采用摄动法,分别选取构件截面摄动和结点势能变化来描述结构所受的初始扰动和因此而引起的间接后果。利用传递矩阵建立两者之间的关系,通过研究传递矩阵各列向量及矩阵本身的性质,来评估构件的重要性和结构的鲁棒性,同时指出具有较高重要性的构件就是结构的命门所在。最后以一个框架结构作为算例进行分析,验证了本文所给鲁棒性指标的合理性。

Structural robustness is the ability of a structure to avoid disproportional consequences in the face of local damages.It has been deemed to be one of the indispensable measures to ensure the safety of structure by improving structural robustness,which is as important as increasing the member strength and reinforcing the construction supervision.The purpose of the robustness analysis is to quantify such an ability of the structure and to identify the most vulnerable part of the overall system.The perturbation method was used.The perturbation of member sections and the variation of nodal potential energy were chosen to describe the structural disturbance and the indirect consequences,respectively.A transfer matrix was used to establish the relationship between the two quantities.By studying the properties of the column vector and the matrix itself,the member importance and the structural robustness can be revealed.The highly important member shows the defect of the structure.A frame structure was analyzed as an example to verify the rationality of the robustness index.