温度作用下钢柱屈曲性能分析

Analysis on buckling performance of steel column under action temperature

为了讨论两端简支钢柱在温度荷载作用下的弹性稳定性,考虑了温度沿钢柱截面非均匀分布的影响,基于构件的非线性位移应变关系,利用能量原理推导了钢柱的非线性平衡方程及屈曲方程,给出了计算临界屈曲温度荷载的方法.由分析结果可知,温度变化对钢柱的稳定性影响很大,当钢柱长细比较大时,即使温度变化值较小也能引起钢柱的屈曲;当钢柱温度变化沿截面均匀分布时,利用提出方法所求得的临界屈曲温度荷载与经典欧拉方法一致;当柱截面平均温度变化为零时,沿截面的不均匀温度分布不会引起钢柱的屈曲.温度沿截面的不均匀分布对于钢柱的稳定性是有利的,而且随着构件长细比的增大,沿截面温度不均匀分布对钢柱稳定性的有利作用增强.有限元验证结果说明所提出的方法可用于温度作用下钢柱屈曲性能的分析.

In order to discuss the elastic stability of a steel column with two simple supported ends under the action of temperature load,the influence of non-uniform distribution of temperature along the cross section of steel column was considered,and the energy principle was used to derive the nonlinear equilibrium equations and buckling equations for steel column based on the nonlinear displacement-strain relationship for components.In addition,a calculating method for the critical buckling temperature load was proposed.The analysis results show that the temperature change has significant effect on the stability of steel column.When the slenderness ratio of steel column is larger,small change in temperature can also induce the buckling of steel column.When the temperature change distributes uniformly along the cross section of steel column,the critical buckling temperature load obtained with the proposed method coincides with that attained with the classical Euler method.When the average temperature change along the cross section of steel column is zero,the non-uniform distribution of temperature along the cross section will not cause the buckling of steel column.The non-uniform distribution of temperature along the cross section is beneficial for the stability of steel column.Moreover,with increasing the slenderness ratio of components,the advantageous effect of non-uniform distribution of temperature along the cross section on the stability of steel column gets enhanced.The results of finite element analysis verify that the proposed method can be used for the analysis on buckling performance of steel column under temperature action.