2 results
Now showing1 - 2 of 2
- Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Effective stress determination for flat bars with sharp notches by combining the theory of critical distances with artificial neural networks(Elsevier, 2026-04-17); ; ; ; This work systematically quantifies the deviations of gradient methods from the Theory of Critical Distances (TCD) and introduces neural-network-based metamodels for the rapid prediction of effective stresses in notched flat bars. Stress-based fatigue and fracture assessment methods often rely on the local stress field around a notch and are commonly referred to as effective stress or stress-gradient methods. In this study, notched flat bars are examined as a representative structural detail. The influence of geometrical variation, critical distance, loading, and plane state on the resulting effective stresses is investigated using the point, line, and area methods of TCD. Deviations of up to 40% are identified across certain geometry–loading combinations, highlighting the sensitivity of TCD based assessment to parameter variations. To eliminate the need for a dedicated numerical simulation for every new notch geometry, a series of feedforward artificial neural network (ANN) metamodels is developed and trained on thousands of finite element simulations. Particular attention is given to the effect of optimization algorithms on training performance and predictive robustness. The resulting metamodels provide fast and accurate estimates of effective stresses across a wide range of geometries and loading conditions, offering a computationally efficient alternative to repeated finite element analysis for the assessment of notched components.Publicationtype: Journal Article13 15 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Comparison of different types of stress gradient methods belonging to the theory of critical distances(2021-12-15)Notches are almost unavoidable in material production. A notched geometry may cause crack initiation which can be followed by crack growth and in the end material failure. Gradient methods are one of the easiest and most useful analytical methods to calculate stress concentrations around the notches. In this project thesis, different gradient methods are compared for a simple plane stress example with different notch geometries. FEM analysis is done for the notched geometries to find resulting stresses. Stress concentrations around the notches are calculated with different stress gradient methods. These stress gradient methods, point method, line method and are method are compared for different critical distances. Up to 45% difference is found between calculated effective stresses between AM and the other two methods which may lead to critical differences in fatigue life.Publicationtype: Report121 329