摘要
Hail impact is a major challenge encountered by aircraft in flight,and thus is a key concern in the design of damage-tolerant composite T-joints in aviation.The study uses the Z-pinning technique(the pre-hole insertion technology)in combination with fillets of two radiuses to manufacture four types of Carbon Fiber Reinforced Polymers(CFRP)T-joints.The T-joints are then subjected to hail impact tests at two energy levels,as well as post-impact quasi-static tensile tests.The results show that increasing the size of the deltoid and Z-pin-induced reinforcement has a limited influence on the responses of the T-joints to hail impact,but a significant influence on their residual tensile strength after impact.These influences are not only dependent on the structural characteristics of the T-joints,but are also closely related to the degree of discrete damage within the T-joints caused by hail impact.Acoustic Emission(AE)technology is used to monitor the quantitative evolution of damage to the T-joints in a timely manner during the loading process,and helps characterize the characteristics of evolution of various types of damage over different periods.The research here can help design lightweight and damage-tolerant T-joints.
