型钢混凝土T形柱框架节点 恢复力模型研究

In order to research the seismic energy dissipation mechanism of T-shaped steel reinforced concrete (SRC) column frame joints,nine T-shaped SRC column-concrete beam planar joints and nine T-shaped SRC column-steel beam 3D joints were tested under low cyclic reversed loading test.According to the test results,the trilinear skeleton curve model of these frame joints considering descent segment was put forward,which was characterized by the yield point,peak point and failure point.Based on the test parameters,the formulas of feature point values were established.The hysteretic loops of T-shaped SRC column frame joints configured with different shape steel forms were simplified according to the test hysteretic characteristics.The cycle degradation indices based on damage was proposed to describe the degradation law of specimen mechanical properties such as the yield load,the maximum load,the unloading stiffness and the reloading stiffness.And then,the restoring force model of T-shaped SRC column frame joints based on damage effect was established.Finally,the validity of the proposed restoring force model was verified by comparison with the test results.The result shows that this restoring force model can well predict the hysteretic characteristics of T-shaped SRC column frame joints under reversed loading,so that the study results can provide theoretical support for the elastic-plastic dynamic analysis of these substructures under earthquake action.