Thanh Tung Nguyen

On the choice of parameters in the phase field method for simulating crack initiation with experimental validation

The phase field method is a versatile simulation framework for studying initiation and propagation of complex crack networks without dependence to the finite element mesh. In this paper, we discuss the influence of parameters in the method and provide experimental validations of crack initiation and propagation in plaster specimens. More specifically, we show by theoretical and experimental analyses that the regularization length should be interpreted as a material parameter, and identified experimentally as it. Qualitative and quantitative comparisons between numerical predictions and experimental data are provided. We show that the phase field method can predict accurately crack initiation and propagation in plaster specimens in compression with respect to experiments, when the material parameters, including the characteristic length are identified by other simple experimental tests.

Modeling of Complex Microcracking in Quasi-Brittle Materials: Numerical Methods and Experimental Validations

Abstract: Predicting the strength due to cracking in quasi-brittle materials such as rocks, concrete or civil engineering materials is of formidable interest. Crack propagation modeling in brittle materials or quasi-brittle materials has long been restricted to simple academic cases and to the macroscopic scale. With recent advances in both numerical simulation methods and experimental characterisation tests, new studies are now possible, allowing the development of fracture models at the microscale, and from realistic microstructure morphologies of complex materials. However, developing predictive models of crack initiation and propagation in three-dimensional (3D) complex and heterogeneous microstructures is highly challenging in regards to modeling, numerical simulation methods and experimental characterization.