为了研究钢筋混凝土框架变梁中节点在地震荷载作用下的受力性能及变形特点,通过10个梁高不等的钢筋混凝土框架中节点试件在低周反复荷载作用下的试验,重点分析该类中节点试件的破坏特点和层间变形能力。研究结果表明:变梁中节点通裂荷载与极限荷载接近,外荷载作用下各试件均发生了核心区剪切破坏,该类节点抗震性能较差,不能满足刚性节点设计的要求。进一步的层间变形能力分析表明,变梁中节点可以较好地满足弹性阶段的变形要求,以通裂阶段作为极限状态控制设计时不能满足弹塑性阶段的变形要求,故在节点核心区抗震验算时建议核心区抗剪强度乘以一个小于1的安全储备系数以确保整体结构的安全。
Ten specimens of reinforced concrete interior joints with different depth beams were tested under reversed cyclic loading.The experimental study was conducted that focused on the failure characteristics and layer deformation capacity of beam column subassemblage.Results indicated that the critical crack load was quite nearly with the ultimate load of interior joints and the seismic behavior was poorer than that of ordinary joints,and the shear failures of all the specimens appeared in the large core under external loads,which can not meet the design requirement of a rigid joint.Furthermore,the layer deformation capacity analysis indicated that the deformation capacity of interior joint can satisfy the deformation demand in the elastic stage.However,the deformation capacity can not satisfy the deformation demand in the elastic-plastic stage based on the critical crack stage design.Thus,a security reserve coefficient was suggested in the seismic design of joints for RC structures to preserve the structural integrity.