A mixed-enhanced strain method Part II: Geometrically nonlinear problems

In Part 1 of this paper we presented a mixed-enhanced approach to formulati ng elements for application to geometrically linear problems. In the presen t work we consider an extension to the geometrically nonlinear case. A mixe d deformation gradient is presented and enhancements developed, resulting i n a formulation which produces coarse mesh accuracy in bending dominated pr oblems and locking-free response in the near incompressible limit. As in Pa rt 1, variational stress recovery is permissible, due to the mixed fields p resent. Representative simulations illustrate the performance of the formul ation in the setting of incompressible hyperelasticity. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.