有限元模型修正研究进展:从线性到非线性

有限元分析在实际工程中得到了广泛应用.然而有限元模型由于受到网格划分、边界条件和材料物理参数不确定性等的影响,与真实结构有差异. 因此须通过试验数据加以修正,使其尽可能接近实际结构,以保证之后的结构动力模拟分析和监测等具有实际意义. 经过多年发展,有限元模型修正技术已经能够成功应用于一些实际工程,但现代工程技术的进步对有限元模型修正提出了更高要求,修正后的有限元模型不仅要有较高的精确度,还需要为后续应用给出具有指导意义的置信度.而现有的有限元模型修正、确认方法多基于结构线性的假设,而未能考虑实际结构中广泛存在的非线性.因此本文以土木工程结构模型修正的一些研究成果为例,通过对传统有限元模型修正的发展历程进行全面回顾;总结评述传统有限元修正技术的主要方法,以及包括有限元模型确认在内的最新研究进展;重点探讨有限元模型修正技术向非线性发展的技术路线和目前主要研究成果,展望其未来发展方向, 并提出值得研究的问题. 

Recent progress on finite element model updating: From linearity to nonlinearity

Finite element (FE) analysis is extensively applied in practical engineering. However, FE model usually differs much from actual engineering structures due to modeling errors caused by meshing scales, boundary conditions, and material properties. Therefore an FE model has to be modified or updated by test data to make the FE model as close as possible to the real structure so that the updated model can be convincingly used for structural simulation, dynamic analysis, health monitoring or other engineering applications. Over the years, although FE model updating has been applied to many engineering applications successfully, the development of modern technology has put forward higher requirements on updated models, not only higher accuracy level but also higher confidence level. However, current methods are mostly confined to the linear structure hypothesis, which disagrees with the actual situations in many cases. Based on the background, this paper comprehensively reviews traditional FE model updating techniques with civil engineering structure as an example. Furthermore, influential model updating methods and their progress are surveyed and critically commented including recent progress of FE model validation. Especially, the evolution from linear to nonlinear FE model updating technology and essential research findings are summarized, then attractive perspectives are forecasted, and several promising issues are sketched out.