静力荷载作用下基于敏感性的单层球壳冗余度分析方法研究

Redundancy of a single-layer reticulated dome under static load based on response sensitivity

为合理评估单层球面网壳结构在静力荷载作用下的构件冗余度,以结构应变对单元材料弹性模量的敏感性作为评价指标,综合考虑单元弹性模量变化对结构影响,给出结构构件冗余度评价方法。为验证方法的有效性,将其与利用结构极限承载能力的冗余度评价方法比较。结果表明,基于应变敏感性与利用极限承载能力分别计算的结构冗余度一致。冗余度值的大小是结构单元重要性衡量指标,冗余度值小的结构单元,其失效后将对结构整体性能产生重要影响。冗余特性可决定结构鲁棒性,能体现损伤情况下结构安全性。

Redundancy is a key factor for structural robustness. It reflects the security of a structure under damage. Here, an analysis method based on structural strain response sensitivity was proposed to assess the redundancy of a single-layer reticulated dome under static load. The strain response sensitivity was a derivative of element strain with respect to elastic modulus of structural materials. The effect of changing elastic modulus on a structure was considered in this method. Further, the other redundancy represented with structural loading capacity was used to verify the effectiveness of the proposed method. It was shown that the redundancy of the structure based on the strain response sensitivity is consistent with that based on the loading capacity; the redundancy is an index indicating whether or not a component is important in a structure; those elements with smaller redundancies are the key components in a structure, their failures have great influence on a structure.