设纵向加劲肋后矩形钢管混凝土柱屈曲机制分析及构造建议

Numerical Simulation on Axial Compression Mechanical Behavior of Rectangular Section CFT Columns with Longitudinal Stiffeners

针对搜集的38根设肋试件的轴压试验结果,采用ABAQUS进行了有限元计算。计算结果表明,轴压承载力与试验轴压承载力误差在7%以内,破坏模式与试验破坏模式吻合较好。根据相关试验数据,对加劲肋的工作机理及受力状态进行了分析。分析结果表明,平板加劲肋截面抗弯刚度对试件承载力有明显的影响,应选取合适加劲肋抗弯刚度及截面尺寸,才能既使组合构件的承载性能得到有效发挥,同时用钢量得到合理优化;钢管屈曲模式受加劲肋刚度的影响较大,随着加劲肋刚度的增大,钢管板件逐渐由在板件横向的一个半波转变为两个半波;当加劲肋刚度达到临界刚度后,加劲肋截面面积不再影响钢管屈曲模式,但试件的轴压承载力随加劲肋面积的增大而增大。

According to the results of the axial compression test of 38 specimens with ribs,finite element calculations were performed using ABAQUS.The calculation results show that the error between the axial compression bearing capacity and the test axial compression bearing capacity is within 7%,and the failure mode is in good agreement with the test failure mode.The working mechanism and stress state of the stiffeners were analyzed based on test data.The analysis results show that the flexural stiffness of longitudinal stiffener has a significant effect on the bearing capacity of the specimen.Appropriate flexural stiffness and cross-section dimensions of longitudinal stiffener should be selected so that the bearing performance of the composite component can be effectively exerted and the steel consumption can be reasonably optimized.The local buckling mode of steel tube is notably influenced by flexural stiffness of longitudinal stiffener,and with the increase of the stiffness of the stiffeners,the steel pipe plate gradually changes from one half wave to two half waves in the transverse direction of the plate.When the stiffness of the longitudinal stiffener reaches the critical stiffness,the local buckling mode of steel tube can not be influenced by the cross section of longitudinal stiffener anymore,but the compression load carrying capacity of specimens increased with the increase of the area of cross section of longitudinal stiffener.