The verification and validation of progressive-damage-analysis finite elementmethods are difficult but critical tasks to undertake during their development.Verification exercises assess whether a predictive analysis tool produces results thatare consistent with the fundamental concepts and assumptions of the tool underevaluation. Ideally, closed-form analytical solutions can be derived for which methodverification results can be compared. Problems selected for computational toolverification are often simple and isolate individual features of the tool. In the case ofprogressive damage finite element methods, verifications should be performed toevaluate the ability of the model to predict the initiation of damage and its growththrough the finite element mesh under a variety of conditions.Mabson et al. proposed a test case of a unidirectional, fiber-reinforced plate with acenter crack subjected to tensile loads to evaluate matrix crack propagationpredictions. The problem was modeled using the Abaqus Hashin continuum damagemechanics (CDM) model for fiber-reinforced composites. Different combinations ofmatrix strengths and element sizes were used in the simulations, and the results werecompared to a closed-form solution based on linear elastic fracture mechanics(LEFM). It was determined that the Abaqus CDM model could predict the LEFMsolution of mode Ⅰ cracks only when the finite element mesh density met specificrequirements based on the material properties.This paper presents closed-form LEFM solutions for a center notch mixed mode(CNMM) verification problem. Parametric finite element analyses were developedusing progressive damage analysis methods of both the Discrete Damage Mechanics(DDM) and CDM classes. The progressive damage analysis methods applied in theanalyses of the CNMM problem include CompDam and the Floating Node Method.Analyses were conducted with various mode mixities and element sizes to verify that the damage models were working as intended and to identify any limits ofapplicability.
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