Optimum Buckling Response Model of Grp Composites

ABSTRACT Relevant literature for the modeling and analysis of failure of GRP composites were reviewed. Samples of GRP composites were prepared by hand-lay up. Composites samples were subjected to compressive tests using a tensometer. Mechanical characteristics, such as modulus of elasticity; compressive strength, proportionality limit, elastic limit and critical strain of composites were evaluated from compression tests results. It was found that the compressive strength of all the samples is far below the elastic limit of 129MPa predicted for samples. Buckling strength of Glass reinforced plastics (GRP) is then predicted. Models were developed for GRP composites using the results of the compression tests md finite element results. Polynomial Regression methods were used to establish empirical models. Finite element models are developed following the usual finite element modeling procedures and the visual basic computer programming methods to reduce the computational efforts involved in the evaluation of the matrices associated with evaluation of elements stiffness matrices, nodal load vectors, their assemblies and the solution of model. Computer subroutines were also developed in visual basic to solve the finite element model ibr displacements, strains and stresses following the usual Gauss-Jordan algorithnl. The buckling models developed were optimized by optimization methods of Quadratic interpolation, @adient sear& and Golden section search to obtain optimum buckling strength of approximately 7MPa to 60MPa for GRP working within room and elevated temperatures.