Fracture mechanics simulation of welded joints at  sub-zero temperatures considering the weld  shape

Welded joints are the most common method for connecting steel components, but they are also points of weakness, as they contain, among other things, initial cracks or are unwelded gaps. Most of the fatigue life of a welded joints takes place during the phase of macro crack growth, fracture mechanics models are therefore widely used method to predict the fatigue life. In this thesis, a procedure is developed how fracture mechanics simulations can be conducted automatically for a large number of welded joints with heterogeneous geometries. Therefore, an integrated procedure is developed in which parametric simulation models are generated, fracture mechanically analysed and the results together with their metadata are saved in a selectable master file. Then, the fatigue lives are calculated from the numerical results via the Paris-Erdogan equation and compared with the experimentally determined data. It is shown that by adapting the Paris-Erdogan parameters, high accuracy can be achieved in predicting fatigue lives under sub-zero temperatures. Moreover, a method is described in which a low effort verification of the Paris-Erdogan parameters C and m, separately from each other, by comparing numerical and experimental fatigue lives in a logarithmic space.

Subjects

Negative Celsius temperatures

Fatigue transition temperature

Temperature dependence of fatigue curves

Fatigue testing

Weldment fatigue

Fatigue

DDC Class

620: Engineering

Lizenz

https://creativecommons.org/licenses/by/4.0/

Name

Fracture mechanics simulation of welded joints at sub-zero temperatures considering the weld shape.pdf

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6.21 MB

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Adobe PDF

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Fracture mechanics simulation of welded joints at sub-zero temperatures considering the weld shape