A simple C~0 isoparametric nine-noded stiffened flat shell element for static analysis of eccentrically stiffened plates/shells

摘要

A flat facet quadrilateral stiffened shell element is developed herein for the analysis of laminated composite stiffened plates and shells by assuming first-order displacement model. The nine-noded c~0 isoparametric flat facet shell element of Lagrangian family with five degrees of freedom at each node is appropriately combined with three-noded C~0 isoparametric beam element with five degrees of freedom, same as that of the shell element, to develop the flat facet stiffened shell element applicable to moderately thick and thin laminated composite plates and shells. The stiffeners are arbitrarily oriented in the shell element. The stiffness matrix of the stiffener is computed first irrespective of its position within the shell element. The stiffness matrix, so computed, is transferred to shell co-ordinate system before assembling in the shell element stiffness matrix at appropriate places.