含预埋元件热塑性复合材料共固化智能结构失效行为

Failure Behaviors of Intelligent Structures Formed by Thermoplastic Composites Co-Cured with Embedded Components

预埋金属连接件并与碳纤维增强热塑性复合材料共固化是实现航空航天、汽车等重要工程领域结构高性能轻量化和智能化设计的有效手段之一,能够有效避免复合材料钻孔带来的力学性能损失以及纤维不连续引起的局部应力集中。该研究将金属连接件预埋入碳纤维/PA6预浸料,采用热压成型工艺制备共固化复合材料结构,考察预埋元件周围纤维连续与不连续结构形式对复合材料结构力学行为的影响,结合超声检测技术,分析智能连接结构损伤破坏模式,并建立相对应的有限元模型,探究因局部纤维结构形式不同所带来的复合材料力学性能和失效行为的差异。结果表明:预埋金属件周围的局部纤维结构形式对碳纤维增强热塑性复合材料的力学性能影响不大,但会带来不同的复合材料失效模式。

The application of carbon fiber reinforced thermoplastic composites, co-curing with embedded metal inserts,is one of the effective methods to realize high-performance lightweight and intelligent design of structures in important engineering fields such as aerospace and automobile. It can effectively avoid the loss in the mechanical properties caused by the drilling of composites and local stress concentration by fiber discontinuity. In this paper, the metal insert was embedded in carbon fiber/PA6 prepreg. The co-cured composites were prepared by the hot-press process. The effects of two different structural forms of continuous and discontinuous fibers around the embedded component on the mechanical behaviors of the composites were investigated. With the aid of the ultrasonic testing technology,the damage and failure modes of intelligent connection structures were analyzed. The influence of the local fiber structure on the mechanical properties and failure behaviors of composites was simulated by adopting the finite element method. The results show that the local fiber structure around the embedded metal inserts has a neglectable influence on the mechanical properties of carbon fiber reinforced thermoplastic composites,but causes different failure modes in composites.