Stress, strain and dissipation accurate 3-field formulation for inelastic isochoric deformation

This work exploits the high accuracy of mixed 3?field u/e/p formulation to address materially non-linear inelastic problems including isochoric deformations. Motivated by strain-driven format several constitutive equations used in FEA, u/s/p is reinterpreted, selecting deviatoric strains as primary variables, together with displacements and pressure field. The complemented suitable for Solid Fluid Mechanics. convergence rate upon mesh refinement, well enhanced stress strain fields proven deformation both elastic ranges. 2D 3D involving different FE discretizations are solved J2?plasticity, J2?damage Bingham models, all them localization. Numerical results show that perfectly convergent mesh-independent achieved terms peak load, failure mechanism, release energy dissipation. Revealing comparison u/p also addressed.