高温下铝合金薄板面内轴压屈曲特性分析

Analysis of In-Plane Axial Compression Buckling Characteristics of Aluminum Alloy Sheet at High Temperatures

研究高温下铝合金薄板面内轴压屈曲特性,结合试验结果证明所建立有限元模型的可靠性.基于模型开展高温下不同参数的屈曲分析,获得薄板的荷载-挠度曲线;运用Mann-Kendall准则,判断初始突变温度.结果表明:恒温加载下,提高边界条件的约束作用、选择短边加载或长宽比较大的截面能有效降低屈曲阶段薄板挠度;恒载升温下,板边缘的转动能有效减小热应力产生的屈曲挠度;长边加载下,选择长宽比较小的薄板能有效降低挠度;初始缺陷影响薄板屈曲时的挠度变化,初始缺陷越大,屈曲阶段挠度变化的斜率越大.

The in-plane axial compression buckling characteristics of aluminum alloy sheet at high temperature are studied,and the reliability of the finite element model is verified by the experimental results.Based on the model,the buckling analysis of different parameters at high temperature is carried out to obtain the load-deflection curves of the sheet.Mann-Kendall rule is used to determine the initial abrupt temperature.The results show that under constant temperature loading,the deflection of sheet can be reduced effectively by improving the constraint of boundary conditions,selecting the short side loading or the section with large length-width ratio;under constant load heating,the rotation of the plate edge can effectively reduce the buckling deflection caused by thermal stress;under long side loading,the deflection can be reduced effectively by choosing sheet with smaller length-width ratio.The initial defect affects the deflection change of the sheet during buckling,and the larger the initial defect leads to the larger slope of the deflection change in the buckling stage.