大型土木结构多目标一致逼近有限元模拟方法

Multi-objective concurrent approaching of simulating for civil infrastructure

阐述了大型土木结构多目标一致逼近模拟中的3个关键问题,即多目标一致逼近有限元模型的建立、单目标多因素同时修正技术及多目标多因素同时修正技术,并从多目标一致逼近模拟的特征和需求等方面来探讨多目标一致逼近模拟策略.重点阐述了多目标一致逼近模拟的建模过程,即如何建立多目标一致逼近有限元模型使之能够同时满足结构损伤分析和状态评估过程中的多目标模拟和结构行为一致多尺度模拟的需求.为考证多目标一致逼近模拟方法的可行性,以焊接钢桁架结构为研究对象,具体阐述了该结构包括一级模拟目标(动力特性)、二级模拟目标(整体名义应力)和三级模拟目标(局部热点应力及其分布规律)的多目标模拟过程.研究结果表明:钢桁架结构多目标一致逼近有限元模型的模拟结果均好于多目标模拟有限元模型,尤其是三级目标的模拟更加准确.

Three key issues of multi-objective concurrent approaching for simulating structural behavior of civil infrastructure have been analyzed,i.e.,the modeling of multi-objective concurrent approaching of simulating, the optimization techniques for concurrent multi-factor as well as for concurrent multi-objective and multi-factor.Then,the modeling process of multi-objective concurrent approaching of simulating is described in detail,in which emphasis is paid on how the developed model could simultaneously satisfy the need of the multi-objective simulating during structural damage analysis and state assessment and the concurrent multi-scale modeling.Finally,the feasibility of the multi-objective concurrent approaching is validated through an example of the welded steel truss structure.The multi-objective simulating process is described including the first-level objective（the dynamical characteristic）,the second-level objective（the nominal stresses in the whole structure）,and the third-level objective（the local hot spot stresses and their distribution）.It is shown from this work that the simulating results of the multi-objective concurrent approaching with the developed FEM（finite element model） of the welded steel truss are much better than those by multi-objective simulating,especially for the third-level objective.