Total Strain Theory and Path-Dependence of Concrete

The nonlinear triaxial behavior of plane concrete that is free of continuous cracks is modeled by an algebraic relation between total strains and stresses, analogous to deformation theory of plasticity. Unloading is not modeled. Good agreement with numerous test data is achieved. The formulation implies algebraic expressions for failure envelopes and some stress-strain curves, which make data fitting easier. The model is enhanced by corrective path-dependent terms that vanish for proportional loading so as extend it for highly nonproportional loading. The principal directions of stress and strain then cease to coincide. In contrast to previous models, the present one applies to much largest atrains, gives the peak stress points, failure envelopes, strain softening, inelastic dilatancy, etc. A tangential incremental form for structural analysis is also indicated.