Effect of ply thickness on displacements and stresses in laminated GFRP cylinder subjected to radial load

The superior feature of composites such as high stiffness against low density have impelled engineers to use this material in automotive, aerospace and building industries. In the past few decades, composites shell has found applications in storage tanks and transmission pipelines. Designing laminated composite shells is challenging because of the complex mechanical behavior when combining laminate and shell theories. In this paper, the study is focused on the effect of lamina thickness on performance of the GFRP cylinder. For this purpose two 12-ply GFRP cylinders are considered with ply sequences of [0/90/45]s. The lamina thicknesses of the composite shell are assumed to be 0.1, 0.5, 1 and 1.5 mm, to evaluation of the mechanical behaviors of the cylinders and identifying one with the highest strength. The 250 mm diameter cylinders are subjected to a uniform radial patch load. A code is written for the solution based on the shell theory and classical mechanics of laminated composite using MATLAB software. The results are validated by comparing the present results with those found in literature. A good correlation justifies the study being extended to include the study on the effect of ply and shell thickness. The procedure is recommended for design and optimization for strength of various sizes of composite pipe

Static analysis of stitched sandwich beams with functionally graded foam core

In this paper static analysis of a cantilever functionally graded sandwich beam under uniform distributed loads is carried out numerically. The beam is composed of two glass fiber reinforced plastic (GFRP) facesheets and a graded Corecell A-series foam core. The composite skins and foam core are stitched together using the same glass fiber. A finite element (FE) model is developed employing a FE commercial code to determine the stresses and deflections. To find the effect of quality of foam gradation through the thickness of the core on the deflections and stresses numerical experiments are performed. Results revealed that the quality of gradation of the foam core affected the displacements and stresses significantly so that an optimal gradation of foam can minimize the deflection, stresses and weight of the sandwich beam