侧边边界条件对铝合金加筋板轴压性能的影响

Influence of side boundary condition on compression performance of aluminum alloys stiffened panels

工程实际中,飞机加筋板结构受到梁或墙限制而呈简支状态,侧边受约束的高强铝合金加筋板在轴向压缩时,表现出与侧边自由加筋板不同的压缩特性。本文就此问题进行了试验和数值模拟研究。轴压试验中,通过影像云纹和应变计监测试验件屈曲及后屈曲过程。基于ABAQUS软件建立有限元模型,采用含韧性损伤和剪切损伤的Johnson-Cook本构模型,研究不同侧边约束下加筋板轴压特性。计算结果与试验结果相吻合,研究表明:侧边简支加筋板蒙皮同时发生失稳,而侧边自由加筋板侧边蒙皮首先发生失稳,侧边自由加筋板失稳载荷虽远低于侧边简支加筋板,但其结构破坏强度仅下降约9%。

Engineering aircraft stiffened structure reinforced by a beam or wall panels restriction are simply supported,and high strength aluminum alloys stiffened panels constrained by side boundary will exhibit different compression performance from panels with unsupported side boundary in axial compression. Test and numerical calculation research were conducted to study this phenomenon. Moiré interferometry and strain gauges were used to monitor the buckling and post-buckling process. Based on the software of ABAQUS,a finite element model was developed. Johnson-Cook constitutive model with ductile damage and shear damage was used to study compression performance of panels with different side boundary conditions. The calculated results are coordinated with the tested results very well. The results indicate that all skins of side simply supported panels buckle simultaneously,while only side skins of unsupported panels buckle. Despite the buckling load for unsupported panels is well lower than that for side simply supported panels,the former＇s ultimate load only almost decreases by 9%.