The advanced simulation of fatigue crack growth in complex 3D structures

Abstract

An advanced incremental crack growth algorithm for the three-dimensional (3D) simulation of fatigue crack growth in complex 3D structures with linear elastic material behavior is presented. To perform the crack growth simulation as effectively as possible an accurate stress analysis is done by the boundaryelement method (BEM) in terms of the 3D dual BEM. The question concerning a reliable 3D crack growth criterion is answered based on experimental observations. All criteria under consideration are numerically realized by a predictor-corrector procedure. The agreement between numerically determined and experimentally observed crack fronts will be shown on both fracture specimens and an industrial application.

Precise 3D crack growth simulations

“…Today, crack propagation is analyzed by numerical simulation, which is based on the concepts mentioned above. A lot of studies on the numerical treatment of cracks have been done by Kuhn and his colleagues (Mews and Kuhn 1988;Schillig and Kuhn 1992;Russwurm and Kuhn 1991;Huber et al 1996;Plank and Kuhn 1999;Partheymüller et al 2000;Kolk and Kuhn 2006;Heyder and Kuhn 2006;Heyder et al 2005). Beside the numerical determination of stress intensity factors (Mews and Kuhn 1988), crack propagation has been simulated in 2D (Schillig and Kuhn 1992) in the late 1980s.…”

“…Then, experiments on crack propagation under non-proportional loading conditions have been performed (Plank and Kuhn 1999) and software for the 3D simulation of fatigue crack growth has been developed (Partheymüller et al 2000). Within the last years, a 3D crack growth criterion including the special treatment of surface breaking points of the crack front has been identified by the comparison of numerical simulations (Kolk and Kuhn 2006) and experimental analyses (Heyder and Kuhn 2006;Heyder et al 2005).…”

Finite Element Method Study on the Squats Growth Simulation

“…A series of approximate methods are currently used for the analysis squat growth problems. The FEM (finite element method), BEM (boundary element method) and mesh free AM method [14][15][16][17][18][19][20][21][22][23][24][25][26] are perhaps the most widely used technique for solving simulating 3D crack growth related problems. In fact, those approaches are either really pseudo-3D (as the modeled crack surface remains planar) or need re-mesh to perform crack automated propagation (This usually involves substantial computational effort).…”

Contribuições às análises de fratura e fadiga de componentes tridimensionais pelo Método dos Elementos de Contorno Dual

“…Métodos sem malhas, a teoria peridinâmica e modelos de campo de fase aparecem como alternativas mais recentes para abordar esses fenômenos de fratura (RABCZUC et al 2010;HA e BOBARU, 2010;BORDEN et al, 2012). Já no caso de problemas de propagação quase estática de fissuras dominantes em regime de fadiga em componentes mecânicoestruturais com geometrias/topologias complexas o MEC-dual, o MEFG/MEFE e também o GLE tem sido utilizados com sucesso na literatura em diversos trabalhos (KOLK & KUHN, 2006;PEREIRA et al 2010;PATHAK et al 2014), pois apresentam características vantajosas para esses tipos de análise. A seguir apresenta-se uma breve revisão sobre as abordagens numéricas para problemas de fratura, com um enfoque especial em problemas com fissuras dominantes.…”

“…A principal vantagem dos elementos de contorno para problemas de fratura encontra-se na redução de dimensionalidade da malha que faz com que a discretização seja necessária apenas nos contornos externos e nas faces das fissuras. Sendo assim algoritmos mais eficientes podem ser propostos para a propagação aleatória de fissuras (KOLK & KUHN, 2006). Além disso, modelos de análise podem ser obtidos de forma mais direta a partir de modelos geométricos convencionais de CAD (PENG et al 2017a).…”