碳纤维复合材料假脚工艺参数对其冲击后疲劳性能的影响

摘要

Impact damage and fatigue damage after the impact of carbon fiber composites prosthetic foot were analyzed based on the 3D progressive damage theory and finite element method.The influence of composite systems,dimensions and stacking sequences on the impact damage and fatigue property were researched.The results show that the main damage modes of carbon fiber composites prosthetic foot under the impact loading are matrix cracking,fiber crushing and delamination.As the transverse tensile strength decreases,the normal tensile strength and shearing strength and the impact damage area of the composite materials gradually increases,and the fatigue life cycle decreases.With the increase of the thickness of back kneel,matrix cracking gradually increases,delamination decreases slightly and fiber crushing has little change.Although fatigue life cycle increases with increasing thickness of back kneel,the increment of fatigue life cycle is lower than that of the thickness.The stacking sequences have little effect on the impact damage modes of carbon fiber composites prosthetic foot.Increasing the number of 0° layer can improve the fatigue properties of carbon fiber composites prosthetic foot.%基于三维逐渐损伤理论和有限元法,对碳纤维复合材料假脚的冲击及冲击后疲劳破坏过程进行分析,研究了不同的复合材料体系、几何尺寸、纤维铺设方式等工艺参数对碳纤维假脚的冲击损伤及疲劳性能的影响规律.结果表明,在冲击载荷作用下,碳纤维复合材料假脚的损伤模式主要为基体开裂、纤维压缩和分层;复合材料体系的横向和法向拉伸强度以及剪切强度等参数越小,假脚的冲击损伤面积越大,所能承受的疲劳循环次数越低;随着后龙骨厚度的增加,基体开裂损伤面积越来越大,分层损伤面积略有减小,而纤维压缩损伤几乎没有变化.尽管随着后龙骨厚度的增加,假脚的疲劳循环次数逐渐增大,但是相对于厚度的增加量,疲劳循环次数的增加量相对较小;不同铺层参数对碳纤维复合材料假脚的冲击损伤模式几乎没有影响.适度增加0°铺层的含量,可有效提高碳纤维复合材料假脚的疲劳性能.