A COROTATIONAL, UPDATED LAGRANGIAN FORMULATION FOR GEOMETRICALLY NONLINEAR FINITE-ELEMENT ANALYSIS OF SHELL STRUCTURES

A co-rotational, updated Lagrangian formulation for geometrically nonl inear analysis of shells is presented. In this finite element procedur e, a standard updated Lagrangian formulation is employed to generate t he tangent stiffness matrix, and a co-rotational theory is used for up dating element strain, stress and internal force vectors during the Ne wton-Raphson iterations. Large rotation theory has been accommodated t o take into account the nonvectorial characteristic of the rotational degrees-of-freedom. The present procedure is ideally suited for implem entation in existing linear finite element programs and its effectiven ess has been demonstrated by a number of numerical examples.