Comparative studies of 3D-constitutive models for concrete: Application to mixed-mode fracture

This paper focuses on the predictive capabilities of 3D-constitutive models for concrete when used for the simulation of mixed-mode fracture in consequence of shear-tensile loading. For this purpose, two types of constitutive models are chosen. Models belonging to the first type such as the extended Leon model (ELM) and two multi-surface models are formulated within the framework of plasticity theory. The ELM (J. Eng. Mech. (ASCE) 1994; 120: 1983–2011), a single-surface model, accounts for the dependence of the concrete strength on the Lode angle. The first multi-surface model consists of a tension-cut-off for the description of tensile cracking of concrete and a Drucker–Prager surface for the description of compressive failure. To improve the description of concrete cracking, in the second multi-surface model the tension-cut-off function is replaced by three Rankine surfaces. The second type of material models considered in the presented investigation is formulated on the basis of the microplane concept. The performance of the material models is investigated on both the constitutive and the structural level. On the constitutive level, re-analyses of Willam's test are performed. For the assessment of the model performance on the structural level, a double-edge-notched concrete specimen is investigated