Experimental and numerical investigation of fracture and buckling behavior of chopped GFRP cylindrical shells subjected to axial compression load

Due to their attractive mechanical properties such as higher strength-to-weight and stiffness-to-weight ratios, instead of conventional isotropic materials, Fiber Reinforced Polymer (FRP) cylindrical shells are being increasingly used in various engineering applications such as aerospace, oil tanks, liquid storage vessels, and silos. Cylindrical shells may experience axial compression load due to primary loading conditions. For a shell with a closed roof, axial compression load is caused by the weight of the roof. In addition, many shells under other loading conditions can also induce either symmetrical or unsymmetrical axial compression loads. The buckling and failure analysis of cylindrical shells made of composite materials is a complex task when compared to the cylindrical shells made of isotropic materials. There are two main failure modes in the composite cylindrical shells subjected to axial compression load, one associated with material strength of the cylinder wall and the other with buckling of the cylinder wall. This study deals with the behavior of chopped Glass Fiber Reinforced Polymer (GFRP) cylindrical shells subjected to axial compression load with an experimental and numerical procedure. Three specimens were used with the same R/t ratio. In the laboratory, the axial compression load was applied by a vertical hydraulic jack. In order to measure the deformation of the cylindrical specimens during the loading, four Linear Voltage Differential Transformers (LVDTs) were used. The nonlinear static analysis method (Riks) using the ABAQUS/Standard software has been employed, considering the boundary and geometric imperfections. For modelling the cylindrical specimens shells, the four-node quadrilateral element (S4R) was used. The critical load and failure mode were determined using Hashin's failure criteria. The effects of the L/R ratio on these shells are examined. Results indicate that the failure mode of these specimens was material failure because of high thickness-to-radius ratio. In addition the stiffness of the cylindrical shell specimens decreases with increasing the height. The comparison between the experimental results and Finite Element Analysis (EFA) exhibited acceptable adaptation.