反复荷载下屈曲约束支撑混凝土框架结构抗震性能研究

摘要

In order to enhance the seismic performance of reinforced concrete frame structure,the authors establish a structural system of combining buckling-restrained braces(BRBs)and reinforced concrete frame due to the buckling problem of traditional support by compression.Finite software ANSYS was used to conduct the nonlinear analysis of reinforced concrete frame structure under cyclic load,which is compared with the results of pseudo-static test.The conclusion shows that the bearing capacity of reinforced concrete frame with BRBs is improved by 50.75％ than that of the ordinary frame without BRBs;the hysteresis loop area of reinforced concrete frame with BRBs increases significantly in the same displacement magnitude,and the maximum energy dissipation of reinforced frame structure with BRBs is 2.97 times as much as the frame structure without BRBs;the error range of ANSYS finite element simulation results and pseudo static test results can be controlled between 3.40％-17.84％,and the estimated results show that they are fitting well;and the BRBs with a stronger plastic deformation capacity has a good effect on the seismic performance of frame structure.Comparing with the frame structure without BRBs,the hysteretic curve of reinforced concrete frame with BRBs is full,and steel bars in the beams yield before the crushing of concrete which belongs to the typical beam hinge failure mechanism.%为了提高钢筋混凝土框架结构的抗震性能,针对传统支撑受压屈曲的问题,建立了新型屈曲约束支撑和框架结构相结合的结构体系.采用ANSYS有限元软件对安装和不安装屈曲约束支撑混凝土框架在水平往复加载下的抗震性能进行了非线性分析,并与拟静力试验结果进行对比.结果表明:安装屈曲约束支撑框架的承载力较普通无撑框架提高了50.75％;同一位移量级下有撑框架的滞回环面积明显增加,有撑框架的最大耗能是无撑框架的2.97倍;ANSYS有限元模拟结果与拟静力试验结果的误差可以控制在3.40％～17.84％之间,有限元模拟与试验结果吻合较好.在有更强的塑性变形能力的屈曲约束支撑对框架结构的抗震性能有很好的增强作用,相比无屈曲约束支撑的框架结构而言,其滞回曲线较为饱满,混凝土梁中钢筋先于混凝土压碎而发生屈服,属于典型的梁铰破坏机制.