方形设肋薄壁钢管混凝土柱的恢复力模型

为了研究薄壁钢管混凝土柱的抗震性能,对6根方形设肋薄壁钢管混凝土柱在反复荷载作用下的滞回性能进行了试验研究,试验主要参数为轴压比(n=0.3~0.6).结果表明:当轴压比≯0.5时,滞回曲线较为饱满,延性系数均>3以上.随着轴压比的增大,构件的承载力略有提高,延性明显降低.采用有限元程序ABAQUS6.5计算每个试件的荷载-位移滞回曲线,计算结果与试验结果吻合较好.在此基础上进行参数分析,研究混凝土强度、钢板强度、轴压比、长细比、钢板厚度对构件滞回性能的影响.并通过回归分析建立了薄壁钢管混凝土压弯构件的荷载-位移恢复力模型,模型的计算结果与试验结果吻合较好.

Restoring force model of square concrete -filled thin -walled steel tubular column with ribs

In order to study the seismic behavior of concrete-filled thin-walled steel tubular(CFTST) columns,the hysteretic behavior of six CFTST columns with ribs under cyclic loading were investigated by tests,the main parameter was axial load ratio(n=0.3～0.6).Test results show that when the axial load ratio is below 0.5,the specimen has plump hysteretic curve and the ductility coefficient is greater than 3,with the increasing of axial load ratio,the load capacity of column increases slightly,but the ductility decreases significantly.The finite element program ABAQUS6.5 was used to simulate the hysteretic curve of each specimen and the calculated results are in good agreement with the test results.Parameter analysis was carried out and the influence of concrete strength,steel strength,axial load ratio,slenderness ratio and thickness of steel plate on the hysteretic behavior of column were studied.Based on the calculated results,a restoring force model was set up through the regression analysis and the result of the model shows good agreement with the test result.The model can be applied to the elastoplastic dynamic analysis of structure.