一种结构鲁棒性量化方法

结构鲁棒性要求结构具有抵御不成比例倒塌的能力.如何对结构鲁棒性进行定量评价是目前结构工程界最具有挑战性的前沿问题之一.该文从结构承载力的角度出发,改进了一种结构鲁棒性评价中的构件重要性系数,形成了一种新的构件重要性系数.再基于这种构件重要性系数,提出了一种新的结构鲁棒性指标及其评价结构鲁棒性优劣的方法,从而实现了结构鲁棒性的量化.以平面桁架结构和平面框架结构为例,说明了该结构鲁棒性量化方法的计算过程.计算结果表明:总宽度、高度相同的4 种框架结构的鲁棒性指标值的大小顺序与定性分析的结果一致,说明了该鲁棒性指标值的合理性.再对4 种框架结构的鲁棒性指标值进行了比较及分析,得出了一些影响结构鲁棒性的因素,如荷载形式、跨度的均匀性、跨数、支撑等.

A QUANTIFICATION METHOD OF STRUCTURAL ROBUSTNESS

Structural robustness requires that the structure is capable of resisting disproportionate collapse.How to evaluate the structural robustness quantitatively is one of the most challenging problems in structural engineering.From the structural bearing capacity,the paper proposes a new method to calculate the importance coefficients of components.And then according to the importance coefficient,a new indicator of structural robustness and a new method to evaluate it are presented.Therefore,the quantization of structural robustness has been realized.The method for quantizing structural robustness is illustrated in examples which use plane truss structures and plane frame structures.The computation result implies that the ranking of the robustness indicators of 4 plane frame structures which have the same width and height is consistent with the result of the qualitative analysis,showing the rationality of the proposed robustness indicator.At last,through comparing and analyzing the robustness indicators of the 4 frame structures,some factors that affect the structural robustness are obtained,including load type,span uniformity,total span number and brace.