高温环境复合材料螺栓连接振动的防松试验
Anti-loosening Experiment of Composite Bolted Structures Under High-Temperature and Vibration Circumstance

具有耐高温、轻质、高强等特点的复合材料及其连接结构可满足航空航天领域的迫切需求，已广泛应用于工程中。为比较高温振动环境下不同复合材料螺栓连接形式的防松效果，进行了常/高温条件复合材料搭接板的随机振动试验研究。以搭接结构固有频率为评判量，通过对比试件承受振动载荷作用前后的固有频率变化，研究了常/高温环境下高温胶、双螺母防松形式，以及沉头螺栓张角等因素在给定随机振动载荷下对搭接结构连接刚度的影响。研究结果表明：常温随机振动条件下双螺母防松、60°沉头螺栓的防松性能更好；高温环境下，高温胶防松、30°沉头螺栓连接形式性能较优。
Composite structure with characteristics of high temperature resistance, light weight and high strength is the imperative requirement in aerospace field, which has been extensively applied in engineering. In order to compare effectiveness of two anti-loosing techniques, experimental investigations of bolted structures at room/high temperature are undertaken, random vibration test is adopted as the looseness detecting condition. Fundamental frequency of structure is introduced as indicator of loosening status by comparing its value before and after each step of loading. Application of high temperature adhesive and double nutting, along with different chamfer angles of countersunk bolts are examined for their effectiveness of anti-loosening under random vibration. Results show that application of double nutting or 60°countersunk bolts is more effective under room temperature; high temperature adhesive or 30°countersunk bolts is superior under high temperature circumstances.