残余应力对焊接箱形轴压柱整体稳定性能的影响

EFFECTS OF RESIDUAL STRESS ON THE OVERALL STABILITY OF WELDED BOX COLUMNS UNDER AXIAL COMPRESSION

采用有限元参数分析,比较了3种残余应力分布形式、6种箱形截面、6种钢材屈服强度(235~960 MPa)条件下残余应力对焊接箱形轴压柱整体稳定性能的影响。结果表明:残余应力分布形式对构件稳定性能影响较小。按矩形残余应力分布计算可知:当板厚不大于20 mm且宽厚比不大于20时,相同残余应力水平下,截面尺寸对构件稳定性能影响较小;不同屈服强度下残余应力对构件稳定性能有一定影响,且稳定性能随钢材强度增大而提高;截面中拉压残余应力水平对构件稳定性能有较大影响。

In order to investigate the effect of the residual stress on the overall buckling behavior of welded box columns,a series of finite element parametric analysis were conducted. The effects of residual stress with three different residual stress distribution models,six box-section dimensions and six kinds of yield strength from 235 MPa to 960 MPa were compared. The results showed that residual stress distribution models had a little effect on the overall buckling behavior. Further analysis was performed based on the rectangle residual stress distribution model.The results showed that when the columns were with a width-to-thickness ratio between 8 and 20 and with the thickness of plate less than 20 mm,the sectional dimensions had little effect on the stability performance of welded box-section columns if the residual stress was the same. The residual stress of columns with different yield strength had effects on the stability of the box columns,and the stability increased with the increasing of steel strength. The residual stress of cross-section had an obvious influence on the stability of members.