Discrete crack propagation model DCPM variable mesh

In the DCPM, global approach, a crack is represented as a discrete gap along the inter-element boundary. The growth of the crack is determined by strength or fracture mechanics based constitutive models. The progressive physical discontinuity in the system is reflected instantaneously in the finite element model by modifying the mesh during the analysis. It is generally argued that the nonlinear response of concrete dams is dominated by a few discrete long cracks. From this consideration, the discrete crack model may be a sensible choice for dam fracture analysis.. The specific advantages of the DCPM are the abilities to consider explicitly the water penetration and uplift pressure on the crack-open surfaces, the aggregate interlock in the rough cracks, and the direct estimation of crack-opening displacement (COD) profile. The principal disadvantages in applying this model are the difficulty and high computational cost due to continuous change of the finite element topology during the analysis, and the unobjective effects of finite element mesh and crack length increment. A special case of discrete crack modelling is the application of special elements to represent the a priori weak joints in the system, such as the dam-foundation interface and construction joints.

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