The Effect of Thickness Variation on Straight-fiber Composite Laminate

Abstract

 Bending strength is a major criterion in controlling composite materials laminates elements based-structure design. Whereas, design processes that lead to high bending loads (or high strains) of laminate elements can directly reduce structural cost or weight in a number of ways. This study demonstrates the improvements achieved to compression-induced bending loads in rectangular composite material laminates using the concept of simple stiffness variation. The principle is based on placing unidirectional layers within the total thickness of the plate, so that the thickness increases in some places and decreases in others without a loss in axial stiffness or an increase in weight, and This results in an increase in the bending load. The study was carried out according to two models of tailoring, the first depends on increasing the thickness of the edges of the plate, and the second model depends on increasing the thickness in the middle of the plate while keeping the rest of the plate parts fixed in thickness and then increasing the dimensions of the central layer until it covers the entire main plate.

We studied the effect of thickness using ABAQUS software to determine the effect of tailoring fibers on the bending loads of the plate with variable boundary conditions, and we fabricated similar Plates and performed compression tests on them and then compared the results obtained to compare the possible improvement in the stiffness of the Plates and the increase in the bending load compared to the bending loads of regular thickness Plate.