nonlinear dynamic analysis of shells (material and geometric).

in this paper we have discussed the main features of a finite clement program which we have developed for nonlinear dynamic analysis of plates and shells with material and geometric nonlinear behaviour. for this purpose, initially, the finite element model which we have used is briefly described. afterwards, the nonlinear viscoplastic material model in one-dimensional and multi-dimensional media is discussed in detail. then, the explicit dynamic analysis method for nonlinear systems is adressed. considering these ideas, the algorithm used in the computer program ndaps is described next. finally the program has been tested using several benchmarks one of which is discussed in detail.