固化压力对炭纤维复合材料层压板的孔隙和力学性能的影响

孔隙的存在是炭纤维复合材料层压板加工过程中不可避免的缺陷,并且会对炭纤维复合材料结构的性能产生很大的损害.针对(±45°)/(0,90°)_2/ (±45°)]_S炭纤维复合材料层压板,详细分析了层压板内孔隙的尺寸、形状及分布特征.通过施加不同的固化压力制备了不同孔隙率含量的试件.采用显微图像分析技术和性能测试对炭纤维复合材料层压板内孔隙的形态及其对炭纤维复合材料层压板力学性能的影响进行了研究,采用图像分析软件对孔隙的形状和尺寸进行了定量的表征.结果表明,对于铺层为(±45°)/(0,90°)_2/ (±45°)]_S层压板,孔隙主要分布于层间,且都沿着平行于铺层的方向发展.随着固化压力的减小,孔隙率增大、层间剪切强度和压缩强度下降.

Effect of curing pressure on voids and mechanical properties of carbon fiber reinforced composite laminates

The existence of the voids is detrimental for the structure performance of composites. The size, shape and distribution of voids in the (±45°)/(0,90°)_2/ (±45°)]_S carbon fiber reinforced composite laminates used for the aircraft were analyzed. Different void contents were acquired by applying a series of curing pressures. Ultrasonic C-scan and microscopic image analysis were used to study the morphology of voids in the fiber reinforced composite laminates. Quantitative characterization of voids in terms of void size and shape was carried out through image analysis software. The results show that voids are mainly distributed between the layers in (±45°)/(0,90°)_2/(±45°)]_S laminates, which grow up along the direction parallel to plies. The void content increases, but the interlaminar shear strength (ILSS) as well as compress strength decreases with the decrease of curing pressure.