基于损伤本构模型的钢梁局部屈曲临界状态分析

CRITICAL STATE ANALYSIS OF LOCAL BUCKLING IN STEEL BEAM BASED ON DAMAGE CONSTITUTIVE MODEL

钢梁在累积塑性变形影响下,可能会发生局部屈曲现象,因此准确判断其发生位置和时点,对研究钢梁累积损伤破坏行为具有重要意义。以准确计算钢梁局部屈曲临界应力和临界应变为研究目标,针对钢梁在不同材料本构模型下的拟静力有限元分析结果,采用应变-挠度法确定局部屈曲临界状态时的应力、应变及位移等,通过与试验结果的对比,表明利用Chaboche非线性随动强化本构模型可以有效反映钢梁局部屈曲临界状态。指出上述方法可以用于研究同类问题时的试验测点布置。

Under the influence of cumulative plastic deformation,local buckling may occur in steel beams. It is very important to study the damage behavior of steel beams cumulative damage that the position and time points of local buckling are judged. The research objective is calculating accurately critical local buckling stress and strain of steel beams. Through using the constitutive models with different materials,the results of quasi-static finite element analysis of steel beams were compared,and then the strain deflection method was used to determine the stress,strain and displacement etc. at the critical state of local buckling. The results showed that the Chaboche nonlinear with kinematic hardening constitutive model could effectively reflect the critical local buckling state of steel beams through the comparison with the experimental results.This paper indicated that the above methods might be applied to the placement of measuring points of experiments.