On an estimation of the exponent of the stress singularity: three dimensional problems and effect of residual stresses on a crack arrested on the interface

0434992 - ÚFM 2015 RIV CZ eng C - Konferenční příspěvek (zahraniční konf.)
Máša, Bohuslav - Náhlík, Luboš - Hutař, Pavel
On an estimation of the exponent of the stress singularity: three dimensional problems and effect of residual stresses on a crack arrested on the interface.
Engineering Mechanics 2014. 20th International conference. May 12-15, 2014, Svratka, Czech Republic. Book of full texts. Brno: Brno University of Technology. Institute of Solid Mechanics, Mechatronics and Biomechanics, 2014 - (Fuis, V.), s. 392-395. ISBN 978-80-214-4871-1. ISSN 1805-8248.
[Engineering Mechanics 2014 /20./. Svratka (CZ), 12.05.2014-15.05.2014]
Grant CEP: GA MŠMT(CZ) EE2.3.30.0063
Institucionální podpora: RVO:68081723
Klíčová slova: Stress singularity exponent * Residual stress * Singular stress concentrator * Material interface * Ceramic composites
Kód oboru RIV: JI - Kompozitní materiály

The main aim of this paper is an investigation of the crack behavior in the ceramics laminates. Especially, the problem of the estimation of the stress singularity exponent in such a material using different approaches is closely described. Since analytical approach is a suitable tool for two dimensional problems, introducing residual stresses, which can be result of used procedures during composite production, may influence value of the stress singularity exponent. Unfortunately, there is formally no analytical tool available to introduce residual stresses. Moreover, when the three dimensional geometry is investigated, effects of complicated stress distribution in front of the crack tip are of crucial importance for crack behavior. Hence using numerically obtained stress distribution appears to be the only way, how to capture the effect of residual stresses and three dimensional geometry of the crack front. The stress singularity exponent can be directly determined from stress components in front of the crack tip and/or from displacements at faces of the crack. Both can provide good results and give us a solution, which cannot be obtained analytically. In following text the procedure will be described in more detail and shown results obtained on ceramic laminate.
Trvalý link: http://hdl.handle.net/11104/0238939