The effect of constraint level on a crack path

0398701 - ÚFM 2014 RIV GB eng J - Journal Article
Ševčík, Martin - Hutař, Pavel - Náhlík, Luboš - Seitl, Stanislav
The effect of constraint level on a crack path.
Engineering Failure Analysis. Roč. 29, APR (2013), s. 83-92. ISSN 1350-6307. E-ISSN 1873-1961.
[Crack paths 2012. Gaeta, 19.09.2012-21.09.2012]
R&D Projects: GA ČR GA106/09/1954; GA MŠMT(CZ) ED1.1.00/02.0068; GA MŠMT EE2.3.30.0063
Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100420901
Institutional support: RVO:68081723
Keywords : Fracture mechanics * Constraint effect * Crack propagation * MTS criterion * Gear rim
Subject RIV: JL - Materials Fatigue, Friction Mechanics
Impact factor: 1.130, year: 2013

The main aim of the work was to estimate the effect of a constraint on a predicted crack path and indicate cases where the failure of a component could be described more precisely by constraint-based description. Special specimen geometry with a high level of constraint was developed and numerical predictions of the crack path were compared with experimental results. The numerical model was built using commercial software ANSYS and a special procedure for the crack propagation was developed. The numerical prediction of the crack path based on a modified Maximum Tangential Stress (MTS) criterion (the criterion uses a two-parameter description of the stress field around the crack tip) is generally in agreement with the experimental data. The classical MTS criterion was found much more sensitive on the crack increment. Based on our numerical predictions it can be concluded that the modified MTS criterion predicted the crack path more precisely, especially in a case with high constraint level. This assumption is also demonstrated on the practical example of gear failure. A gear with a thin rim induces a relatively high level of constraint. It is shown that the influence of the constraint can significantly change the calculated crack path in specific cases.
Permanent Link: http://hdl.handle.net/11104/0226149