LARGE-DEFORMATION FINITE-ELEMENT ANALYSIS OF LAMINATED CIRCULAR COMPOSITE PLATES

A 48 d.o.f., four-noded quadrilateral laminated composite shell finite element is particularised to a sector finite element and is used for the large deformation analysis of circular composite laminated plates. The strain-displacement relationships for the sector element are obta ined by reducing those of the quadrilateral shell finite element by su bstituting proper values for the geometric parameters. Subsequently, t he linear and tangent stiffness matrices are formulated using conventi onal methods. The Newton-Raphson method is employed as the nonlinear s olution technique. The computer code developed is validated by solving an isotropic case for which results are available in the literature. The method is then applied to solve problems of cylindrically orthotro pic circular plates. Some of the results of cylindrically orthotropic case are compared with those available in the literature. Subsequently , application is made to the case of laminated composite circular plat es having different lay-up schemes. The computer code can handle symme tric/unsymmetric lay-up schemes. The large displacement analysis is us eful in estimating the damage in composite plates caused by low-veloci ty impact.