基于OpenSees的FRP约束混凝土本构开发及墩柱性能分析

Development of FRP Confined Concrete Constitutive Model and Analysis of Pier/Column Behavior Based on OpenSees

OpenSees的纤维单元技术成熟,非线性分析能力强,可应用于桥梁和结构工程的精细化分析,由于OpenSees的材料本构库缺乏完备的纤维增强塑料(FRP)约束混凝土本构,为了用于FRP约束混凝土墩柱分析,需要进行FRP约束混凝土本构开发。通过对部分FRP约束混凝土本构模型进行总结和分析,提出改进的Lam-Teng模型,编制程序将其嵌入OpenSees的材料本构库,成功实现对OpenSees的材料库扩充。对3组FRP约束混凝土墩柱的轴压破坏试验、1组圆形截面FRP约束混凝土墩柱的水平往复加载试验以及1组FRP加固既有损伤桥墩的加固后滞回性能试验进行了数值模拟,计算预测结果与试验结果吻合程度较好。研究工作表明,基于OpenSees进行本构模型开发的技术路线可行;改进的Lam-Teng模型能准确刻画FRP约束混凝土墩柱的受力性能,预测结果准确可靠。

The fiber element technology of OpenSees is mature, has powerful capacity of non- linear analysis and can be therefore used for the refined analysis of bridge and structural engineer- ing. However, as the sophisticated constitutive models for the FRP （fiber reinforced plastic） con- fined concrete are not available in the material library of the current OpenSees, the constitutive models for the concrete need to be developed for sake of the analysis of the FRP confined concrete piers/columns. By reviewing and analyzing part of the constitutive models for the FRP confined concrete, a modified Lam-Teng model is proposed and at the time the program is written, the modified model is built in the material library of the OpenSees and the expansion of the library is consequently successfully realized. The numerical simulation is implemented for the axial compression failure tests of 3 groups of the FRP confined concrete piers/columns, for the horizontal cyclic loading test of 1 group of the circular section FRP confined concrete piers/columns and the hysteretic behavior test of 1 group of the existing damaged piers retrofitted by the FRP and the calculation prediction of the simulation matches well the tests. The results of the work demon- strate that the proposed technical solution to the development of the constitutive models based on the OpenSees is feasible, the modified Lam-Teng model is capable of describing the mechanical behavior of the FRP confined concrete piers/columns and the calculation prediction is accurate and reliable.