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复合材料蜂窝夹芯结构作为一种轻质结构已经被广泛应用于飞机舵面及各类整流罩等部件,而弯曲性能可以综合表征其力学性能。基于此,对复合材料蜂窝夹芯板单面贴补试件进行了试验研究及数值分析。首先对单面贴补试件进行了三点弯曲试验,得出结构的破坏载荷及强度恢复值,并分析了芯层压溃以及补片脱胶两种破坏模式及其机理。数值分析中,结合Hill准则、Hashin Fabric准则以及粘聚单元技术,以二次应力准则和能量释放率准则作为失效判据,建立了基于梯形本构关系的修补结构三维有限元分析模型。对蜂窝夹芯板单面贴补结构的弯曲强度及破坏机理进行计算与分析,计算结果表明,基于梯形本构关系的胶层模型可以较好地模拟实际脱胶情况,与试验结果能够较好吻合,验证了分析模型的正确性。最后,分析了补片直径以及补片厚度对修补效果的影响,结果表明,随着补片直径与厚度的增加,修补结构承载能力呈现先增加后减小的趋势。
Composite honeycomb sandwich structure as a lightweight structure has been widely used in the aircraft rudder and all kinds of fairings and other components, and bending properties can be a comprehensive characterization of its mechanical properties. Based on this, the experimental study and numerical analysis of single-side attached composite specimens of composite honeycomb sandwich panel were carried out. Firstly, the three-point bending test was carried out on the single-side attached-up specimen, and the damage load and strength recovery values of the structure were obtained. The failure modes of the core layer and the degumming of the patch and their mechanism were analyzed. In the numerical analysis, combined with the Hill criterion, Hashin Fabric criterion and cohesive element technique, the three-dimensional finite element analysis model of repaired structure based on trapezoidal constitutive relation was established by using the criterion of secondary stress and energy release rate as failure criteria. The bending strength and failure mechanism of one-side sandwich structure of honeycomb sandwich panel are calculated and analyzed. The calculation results show that the model based on the trapezoidal constitutive relation can simulate the actual degumming well, which is in good agreement with the experimental results. Verify the correctness of the analysis model. Finally, the effects of patch diameter and patch thickness on the repair effect are analyzed. The results show that with the increase of patch diameter and thickness, the carrying capacity of patch repair structure firstly increases and then decreases.