Numerical calculation technique for large elastic-plastic transient deformations of thin shells.

Abstract

Studies of explosive forming of structures must often include the large-deformation transient and permanent-deflection responses of the structure. To aid in studies of this nature, a large-deflection elasticplastic transient response prediction method has been developed. The accuracy and reliability of this method have been demonstrated by comparisons of theoretical predictions with experimental measurements. The large-deflection largerotation small-strain equations of motion for a thin shell including elastic, elasticplastic, strainhardening, and strain-rate material behavior are presented in tensor form. These equations are then cast into numerical form by finite differencing. The step-by-step numerical-integration technique is applied to the case of a cylindrical panel; dynamic-deformation predictions are compared with experimentally observed deformation histories of an explosively loaded cylindrical panel tested at the Picatinny Arsenal.