Determination of mechanical characteristics of filament wound composite pipes containing nano graphene particles

This research aimed to determine the mechanical characteristics of basalt fiber-reinforced polymer pipes (BFRPs) containing graphene nanoplatelets (GNPs). The samples fabricated by the filament winding technique were prepared at various amounts of GNP (0.1 wt.%, 0.25 wt.%, 1.00 wt.%, 2.00 wt.%, and 3.00 wt.%). The samples' axial compression response and stiffness were measured using ASTM D695 and ASTM D2412 standard tests, respectively. Furthermore, the samples were compressed in the axial and lateral directions to obtain crushing characteristics. To comprehend fracture behavior, failure modes were explored for each experiment. The GNP addition showed remarkable effects on the examined mechanical properties of the BFRPs. The quasi-static compression performance of BFRP samples loaded with GNP improved compression strength in the axial direction while increasing pipe stiffness in the radial direction. Crushing test results in the axial and lateral directions of the tested sample were found to be more stable and consistent when compared to pure pipes. The results demonstrated that the samples containing 0.25 wt.% GNP provided the best values of specific absorption energy for both axial and lateral crushing. This was attributed to the better load transferring ability between epoxy matrix and basalt fiber by adding GNP particles. Progressive failures with splaying and frond formations were observed in the crush histories of GNP-doped samples. Also, a higher amount of GNP addition, such as 3 wt.% led to decreases in the crushing characteristics and the compression performance of the samples. This occurred due to agglomeration formations into the epoxy matrix, which causes local stress concentrations. To sum up, GNP filler affected the compression and the crushing properties of the pipe samples, and it was considered a good solution to improve the mechanical characteristics of pipes.