基于OpenSees的屈曲约束支撑混凝土框架静力弹塑性分析

Nonlinear Static Push-Over Analysis on BRB Frame Structure Based on OpenSees

目的为给出合理的抗震设计建议,研究不同参数的屈曲约束支撑混凝土框架结构的抗震性能.方法对一个四层三跨的混凝土框架结构进行静力弹塑性分析.建立模型过程中,同时考虑材料的非线性,构件的几何非线性.在此基础上,分析外围钢管的刚度、夹层混凝土的强度、内芯软钢的刚度对混凝土框架结构抗震性能的影响.结果屈曲约束支撑外围套管的厚度对其抗震性能有着较大的影响,建议采用厚度为5 mm的钢管.不同约束混凝土强度对屈曲约束支撑抗震的性能影响:层间位移角相差不到10%,属次要因素,混凝土采用C20即可.结论屈曲约束支撑混凝土框架结构具有良好的抗震性能,屈曲约束支撑外围刚度对框架结构的抗震性能影响最大,内部约束混凝土的强度对其影响不大.

To give reasonable seismic design suggestions, this paper studied the seismic perform- ance of buckling-restrained brace( BRB )concrete frames with different parameters. Taking into ac- count of geometric nonlinearity and material nonlinearity, a model for concrete frame structure of 4 stories and 3 bays was built and analyzed. Based on this basis, influences of stiffness of the external steel tube, strength of the concrete and stiffness of the core steel on the seismic performance of BRB were obtained. It is found that the external steel tube thickness has significant influence on the seismic performance and steel tube with thickness 5 rnm should be used. The story drift of restrain- ed concrete frames is within 10%, that means the influence of restrained concrete strength is secondary. Using C20 concrete is appropriate. Conclusion is that concrete frame with BRB has good seismic performance. The peripheral stiffness of BRB has significant effect on the seismic perform- ance;but the influence of strength of internal restrained concrete is small.