基于响应面的桥梁有限元模型修正

Response-surface based on finite element model updating of bridge structures

采用试验设计和回归分析方法,以显式的响应面模型逼近特征量与设计参数间复杂的隐式函数关系,得到简化的结构模型(Meta-model),给出有限元模型修正过程。针对复杂的土木工程结构,讨论样本选择、修正参数选取以及如何从众多因素中较合理地建立结构的响应面模型。用数值模拟算例和六跨连续梁桥环境振动试验结果,实现基于响应面模型的土木工程结构有限元模型修正,并与传统的基于灵敏度方法直接对结构有限元模型修正结果进行比较。结果表明,基于响应面方法的有限元模型修正和验证,能显著提高修正的效率,修正过程计算简洁、迭代收敛快,避开每次迭代都需要进行有限元计算,易于工程实际应用。

Using experiment design and regression techniques, a fast-running response surface model （meta-model） is formulated to approximate the time-consuming multivariate input/output relationships of a physical-based computer finite element model. A response-surface based finite element model updating procedure for bridge structures is proposed. The work is focused on sampling, selecting the significant updating parameters and constructing a reasonable quadratic polynomial response surface. The approach is illustrated for a simulated simply-supported beam and a full-size precast continuous box girder bridge tested in the field under operational vibration conditions. The results have been compared with those obtained from the traditional sensitivity-based finite element model updating method. It is demonstrated that proposed model updating process becomes more efficient and converges faster with the response surface replacing the original finite element model. The method is easy to implement i with available commercial finite element analysis packages.