Bending analysis with Galerkin method of rectilinear orthotropic composite circular plates subject to transversal load

A theoretical analysis of linear elastic behavior of the rectilinear orthotropic composite annular plate undergoing external loads orthogonal with respect to its mid-surface is presented. The annular plate is made of fiber-reinforced layers with rectilinearly oriented fibers. Different stacking sequences, taken from constructive practice, have been considered. An original approach is presented combining the bending plate theory for composite materials, in order to analytically define the governing equations, with the use of Galerkin solution method. This paper represents the first step for the definition of a Spot Joint Element for spot junctions, such as bolts, rivets or generic pins, applied to a composite plate. In this order of ideas, displacement constraints involving clamped outer radius and rigid core at the inner radius, deriving from the theoretical reference model of Spot Joint Element, are taken into account. The expressions of the approximation functions are derived from constraints conditions and depicted in a general formulation. Results for different typologies of composite laminate plates are shown and compared to results derived from FEA performed with a refined reference model.