AbstractAlthough yield stress and its dependence upon temperature and strain rate are well characterized for many thermoplastics, there are a number of scientific and engineering situations that require additional information regarding post‐yield deformation behavior. For example, the prediction of formability in plastics will require a quantitative description of constitutive behavior for strains between 40 and 300 percent, depending on the plastic. Data characterizing this behavior now exists for a number of plastics, and an analytical understanding of its effect on mechanical behavior has also been established. The purpose of this investigation is to apply the experimentally measured large‐strain constitutive behavior of polycarbonate to the analysis of several simple forming experiments and illustrate the accuracy of current predictions in comparison to experiment. Analyses of a tensile test, a “bend‐stretch” forming experiment, and the indentation of a circular disc by a hemispherical punch are compared with experiments. Agreement between analysis and experiment is very good for all geometries c