Study of the New Leon model for concrete failure

The New Leon model (NLM) is based on a combination of the flow theory of plasticity and damage mechanics. First, the damage evolution law of the model, which yields finite element mesh size-dependent results, was regularized. The slope of the softening curve predicted by the model was slightly too flat compared with uniaxial tensile test results; thus, the evolution law of the damage variable was enhanced to correct defects. The yield function of the New Leon model had two vertices at the intersection with the hydrostatic axis. To avoid this problem, the stress state was assumed to be projected onto the hydrostatic axis in the first vertex and along the hydrostatic axis in the second. The New Leon model was then compared with the Extended Leon model in a first experiment by Hurlbut and a second experiment by Imran. Finally, the New Leon, extended finite element, and gradient enhanced damage models were applied to plain concrete tests to simulate the cracking of concrete, and crack mouth opening displacement results were obtained. Compared with other models, the New Leon model yielded values that were generally in better agreement with the experimental results.