翼肋支撑对复合材料加筋板轴压性能的影响

为确定翼肋支撑对复合材料加筋板轴压性能的影响,对施加翼肋支撑前后的复合材料工型加筋板和帽型加筋板进行压缩试验和数值模拟研究。轴压试验中,通过应变计和影像云纹法实时监测试验件的失稳载荷及失稳模态,通过断面观测分析结构损伤破坏机制。基于ABAQUS软件建立有限元模型模拟加筋板屈曲及后屈曲过程,通过失稳节线及反节线上的应力分布变化分析加筋板破坏机制。计算结果与试验结果相吻合,表明翼肋支撑对不同筋条加筋板失稳模态有影响但均不改变结构失稳载荷,位于节线上的翼肋支撑对工型加筋板破坏载荷影响较小,但位于反节线上的翼肋支撑使帽型加筋板的承载能力提高了26.2%。试验件失稳后应力向反节线上筋条蒙皮界面集中,过高的应力导致界面脱粘,使得结构集中在反节线上破坏。 

Effects of rib support on axial compression behaviors of composite stiffened panels

In order to determine effects of rib support on axial compression behaviors of composite stiffened panels, composite stiffened panels with I shape and hat shape cross-section without and with rib support were investigated experimentally and numerically. In axial compression tests, strain gauge and Moiré interferometry were used to monitor timely the buckling load and buckling modes of specimens, fracture section was observed aimed to analyze the fracture mechanism of structural damage. Based on the software of ABAQUS, a finite element model was developed to simulate the buckling and post-buckling progress of the stiffened panels, then the damage mechanism of stiffened panels was further analyzed by stress distribution evolution on the buckled antinode line and node line. The calculated results are coordinated with the testing results very well. The results indicate that the rib support has changed buckling mode but no impact on the buckling load for stiffened panels with different types of stiffener. The collapse load has a slight difference between with the rib support and without the support on the node line for the stiffened panels with I shape stringer, while that of the former panels has increased by 26.2% than the latter panels for the stiffened panels with hat shape stringer which the rib support was located on the antinode line. Stress distribution concentrates into interface between the stiffener and skin on the antinode line, high stress will induce interface debond, which will lead to collapse of structures concentrating on the antinode line.