基于声发射技术的大容积玻璃纤维缠绕气瓶冲击损伤评定

Impact damage evaluation of large volume glass fiber wrapped gas cylinder based on AE technology

通过对大容积玻璃纤维缠绕气瓶分步升压爆破试验,采用声发射技术,监测分步升压爆破过程中缠绕层损伤演化以及不同升压阶段声发射信号响应特征,得到不同阶段声发射信号幅度、计数、累计计数以及能量等特征,试验压力由40 MPa升至50 MPa阶段,缠绕层发生损伤,声发射信号活性增加约90倍,且纤维断裂信号强度较高,达到1.0×10^(8)aJ。在此基础上,通过对带有不同程度冲击损伤气瓶升压爆破试验,对比分析0~30 MPa阶段不同损伤气瓶声发射响应区别。试验结果表明,缠绕层声发射信号随缠绕损伤程度增加,响应幅度增高,信号活性增强,强度增大,临界损伤气瓶缠绕层信号活性增强约20倍,信号强度可达到2.0×10^(6)aJ,增大约10倍。因此,可在水压试验过程中,通过冲击损伤区域声发射信号幅度、计数等特征和临界损伤缠绕层信号特征对比,对冲击损伤进行安全评定。

Here, through step-by-step pressure boosting blast tests for large volume glass fiber wrapped gas cylinder, acoustic emission(AE) technology was used to monitor damage evolution of wrapped layer in step-by-step pressure boosting blast process and response characteristics of AE signals in different pressure boosting stages to obtain AE signal amplitude, count, cumulative count, energy and other characteristics in different stages. It was shown that when test pressure rises from 40 MPa to 50 MPa, wrapped layer is damaged, and AE signal activity increases by about 90 times, fiber breaking signal strength is higher to reach 1.0×10^(8)aJ. Then, differences of AE responses of different damaged cylinders at 0-30 MPa stage were analyzed contrastively through pressure boosting blast tests of cylinders with different degrees of impact damage. The test results showed that response amplitude, signal activity and strength of AE signals of winding layer increase with increase in degree of winding damage;AE signal activity of winding layer of critical damage cylinder increases about 20 times, AE signal strength can reach 2.0×10^(6) aJ and increases by about 10 times;during hydraulic pressure tests, the safety of impact damage can be evaluated by comparing AE signal amplitude, count and other characteristics of impact damage area with AE signal characteristics of critical damage winding layer.