Experimental and Numerical Analysis of the Effect of Filament Curvature Pattern on the Internal Hydrostatic Threshold of GFRP Composite Cylinder Made by Filament Winding Process

The filament winding process is one of the most important and widely used processes in the manufacture of composite structures in order to achieve high strength and rigidity. In this process, there are important parameters such as fiber tension, how the fibers are twisted, the effect of layering, twisting angle, twisting pattern of fibers, materials, etc. which can play a significant role in this process. In this regard, the twisting pattern has been less studied by researchers than other parameters. In this research, the effect of fiber twisting pattern on the hydrostatic pressure threshold of epoxy glass cylinder has been investigated. For this purpose, glass/epoxy cylinders with 4 different twisting patterns were made with ± 54 arrangement and subjected to hydrostatic test with internal pressures of 5-50 bar, where the amount of radial displacement in the middle of the cylinder was measured experimentally. In the following, the radial displacement of cylinders due to the internal pressure was also modeled using numerical analysis (Abaqus) and compared with experimental results. In order to validate the experimental and numerical results, theoretical model was used and the results were compared. All of the results obtained were in acceptable limits and showed that the pattern having finer texture has a higher compressive strength. Also, the simulation results showed a good agreement with the experimental results.