复合材料后压力框开口增强方式的比较研究

COMPARATIVE STUDIES ON CUTOUT ZONE REINFORCEMENGT OF COMPOSITE REAR PRESSURE BULKHEAD

为了研究机身后压力框开孔不同增强方式对于结构的影响,该文首先开展了缎纹碳纤维织物环氧复合材料在开孔不同增强形式下的双轴拉伸试验,依照试验条件,建立了有限元模型,探讨了增强方式的有效性和不同增强方式的差异。试验与模拟结果表明:双轴拉伸载荷作用下的十字形复合材料试件上各铺层的应变,以当前层的经向作为对称轴,对称分布;两种增强方式均能有效对开孔进行增强,分析孔边应变分布特征,并综合各铺层内的最大应变值和工艺因素等因素,发现复合材料增强效果较好;试验结果和模拟结果相符性良好,证明该文所采用的模拟方法能有效应用于全尺寸后压力框承载性能的分析评估。

To study the influence of the pattern of opening reinforcement on fuselage rear pressure bulkheads, a series of biaxial tensile tests of satin-carbon fabric/epoxy composites reinforced using different opening reinforcement processes were carried out. Based on the test conditions, a finite element model was established.The effectiveness and differences of two reinforcing methods were discussed. The experimental and simulation results show that the strains of each ply are symmetrical to the current ply fiber direction under biaxial tensile loading. In cruciform specimens, both composite stiffening rings and metal stiffening rings can improve the strength of the specimen with large opening effectively. By analyzing strain distribution around the hole, it can be concluded that the composite material reinforcement is more effective, for the maximum strain value is comparatively small and it has better manufacturing properties. The simulation results agreed well with the experimental results, which confirmed that this simulation method can be used in the further evaluation of full scale rear pressure bulkhead performance.