高速列车用碳纤维复合材料结构损伤修复门槛值研究

Research on Threshold Value of Repair for Carbon Fiber Composite Used for High-speed Rail

本文研究了新一代高速列车用碳纤维复合材料的损伤修复问题。首先针对材料进行准静态压痕试验,模拟不同类型、不同程度的冲击类损伤,测量表观损伤尺寸;同时运用无损检测超声C扫的方法分析内部损伤尺寸,表观测量和无损检测参数共同作为表征损伤程度的尺寸类参数;对准静态压痕试验后的带损伤材料进行剩余强度的实验分析,同时运用仿真分析的方法,扩充试验工况,并与试验数据进行对比,建立损伤表观尺寸和无损检测尺寸与剩余强度的关系,最终确定该种材料的损伤缺陷修复门槛。研究结果表明在某种准静态压缩工况(压头尺寸)下,剩余强度保留率与凹坑深度、凹坑最大直径、超声C扫最大直径均可建立递减关系,在实际的工程应用中,可选择其中之一作为损伤的判据。结果表明:超声C扫最大损伤直径在28~34 mm之间,剩余强度保留率在75%~84%之间,考虑到试验结果的离散性,最终选择30 mm无损检测最大损伤直径作为修复的门槛值参数。

In this paper,the damage repair of carbon fiber composites for new generation of high speed trains was studied.Firstly,the quasi-static indentation test was carried out to simulate different types and degrees of impact damage and to measure the dent size.Secondly the internal da-mage size was analyzed by ultrasonic C scanning.The measurement and nondestructive testing results were used as dimension parameters to characterize the damage degree.The compressive residual strength testing of the damaged material after static indentation test was carried out.At the same time the simulation analysis method was used to expand the test conditions and compared with the test data to establish the relationship between the damage size and residual strength.The damage repair threshold value was determined.Experimental results showed that the residual strength can establish a decreasing relationship with the dent depth,the dent maximum diameter and the maximum diameter of ultrasoniced C scanning under quasi-static compression condition of one size compression head.The results show that when the maximum damage diameter of ultrasonic C is between 28 mm and 34 mm and the residual strength is between 75%and 84%.Finally the maximum damage diameter for 30 mm nondestructive testing is chosen as the threshold value of repair.