Quasi-static compression tests of overwrapped composite pressure vessels under low velocity impact

Pressure Vessels are being utilised in different applications that are indispensable including automobile, aerospace, underwater vehicles, oil and gas, chemical engineering among other applications. However, there is lack of knowledge on the influence of induced damage and the resulting performance of such vessels under quasi-static loading and axial compression. Specifically, the vessels studied in this study is made up of a high-density polyethylene liner and glass fibre overwraps. Therefore, this research investigated the load bearing capacities and the energy absorbed of the indented vessels in axial and hoop directions to determine the resistance of the vessels after such damaged using experiment, and damage characterisation microscopy, non-destructive testing and analysis. Quasi-static transverse and axial compression testing was performed on composite cylinders made of polyethylene liner and glass fibre overwraps. Both quasi-static and axial compression tests were performed with the Instron Machine 3382, quasi-static compression was performed at speed of 500 mm/min, while the axial compression test was performed at speed of 2.5 mm/min. The results for the damage profile and the effect on compressive strength of the composite damaged and two non-damaged cylinders was found to be relatively similar. Additionally, the results demonstrate that the quasi-static compression have little or no influence on the axial strength of the cylinders. The microscopic and Dolphicam2 results for damage characterisation on the cylinders revealed fibre break and delamination. On the other hand, visual examination results show local bucking and brooming failure at the bottom of the cylinders.