An Efficient Finite Element Model for Static and Vibration Analysis of Plates With Arbitrarily Located Eccentric Stiffeners

Abstract

Two isoparametric finite element models (QS8S2 and QL9S2) for static and vibration analysis of plates/shells with arbitararily located eccentric stiffeners have been proposed. The eight-noded QS8S2 model and the nine-noded QL9S2 model have been arrived at by appropriately combining Serendipity and Lagrangian plate/shell elements with the three-noded isoparametric beam element, with the use of suitable transformations for eccentricity and arbitrary location in the plate element. This has been achieved without increasing the total number of global degrees of freedom (DOF). Transverse shear deformations are included in the formulation, making the models applicable for both moderately thick and thin plates. Numerical studies have been conducted for static and vibration analysis of concentrically and eccentrically stiffened plates to determine the efficacy of the proposed models. Vibration analysis has been carried out with four mass lumping schemes. The proposed QL9S2 model with a consistent diagonal mass lumping scheme has been found to be more efficient than the QS8S2 model and the other models available in the literature for static and vibration analysis (in the higher frequency/modes range) of stiffened plates/shells with arbitrarily located eccentric stiffeners.