Development of the Simplified Evaluation Method for Strength of FW-FRP Pressure Vessels using Ring Burst Tests

纤维缠绕玻璃钢复合材料在工程部件中发挥着越来越重要的作用，例如压缩天然气汽车火箭发动机壳体和飞轮的燃料气体容器。准确地获得FW-FRP复合材料的材料性能是复合材料设计者面临的重要课题。然而，实际容器的内压试验需要大量的费用和时间，为此，本文提出了一种用于评定FW FRP压力容器强度的简化方法--环形爆破试验。在环形爆破试验中，将锥形棒插入12个分段中，其中设置环形FW FRP试样。在先前的研究中证明，然后在环形样本中获得均匀的 **op应力。然而，由于试验装置的部件之间存在摩擦力，难以研究FRP试件在循环荷载作用下的断裂行为，因此对试验装置进行了改造。采用滚针轴承减小摩擦力。另一方面，本研究的目的之一是拓展冲击损伤后FW FRP压力容器剩余强度的试验能力。遗憾的是，由于铝衬套在冲击载荷作用下发生了较大程度的塑性变形，这一点并没有得到充分的实现。本文介绍了一种新的简化的纤维增强复合材料压力容器剩余强度试验方法，即采用铝管内衬的纤维增强复合材料试件。可以得出结论，这是本研究的一个额外成就。

Filament wound (FW)-FRP composites have played an increasing role in engineering components, i.e. fuel gas containers for the compressed natural gas vehicle rocket motor cases and flywheels. It is important subject for the designer concerning composite materials to obtain the accurate material properties of FW-FRP composites. However, the internal pressure tests of actual vessels need a lot of cost and time.From these reasons, the simplified evaluation technique for the strength of FW FRP pressure vessels, Ring Burst Test, was developed in the present study. In the ring burst tests, the tapered rod was inserted into the 12 divided segments, among which the ring type FW FRP specimen was set. It was demonstrated in the previous study that the uniform **op stress was then obtained in the ring specimen. However, since friction forces were subjected between components of testing apparatus, it was difficult to investigate the fracture behavior of FRP specimen under cyclic loading.Therefore, the modification of test apparatus was carried out. The needle bearings were used to decrease the friction force. Finally the fatigue properties of FW FRP specimens were successfully understood in the present study.On the other hand, one of the objects of this study was the expanding of the test ability to the evaluation of residual strength of FW FRP pressure vessels with impact damages. Unfortunately, it was not accomplished sufficiently because of the large degree of plastic deformation of aluminum liner by impact loading. However, another new simplified tests for the residual strength of FW FRP pressure vessels was introduced by using the FW specimens with aluminum pipes as liners. It can be concluded that this is an additional accomplishment of the present study.