## In this work, a new fracture hypothesis referred to as the Z-criterion is developed for mode III cracks in orthotropic composite materials. The new theory predicts critical crack propagation conditions and the crack propagation direction. The Z-criterion (Zhang et of., Engng
An energy based fracture criterion for mode II crack in fiber composites
โ Scribed by S.Q. Zhang; B.Z. Jano; B.T. Valaire; J.C. Suhling
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 699 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0013-7944
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โฆ Synopsis
The strain energy density factor or .S-criterion [l] has been widely used in fracture mechanics and our work confnms that it can be used to explain the cracking behavior of a homogeneous, isotropic solid. However, it was found to be inadequate for some composite materials and a new hypothesis called the Z-criterion, based on the dilatational strain energy density factor and distortional strain energy factor has been proposed by the current authors. Under mode I conditions, the Z-criterion has been found adequately to predict cracking and now this new approach has been applied to an orthotropic material subjected to mode II loading. Under these conditions it is shown that the dilatational component of the strain energy density is insignificant and so a new criterion has been developed. The new criterion show that the distortional strain energy density factor is the dominant factor for mode II crack analysis.
๐ SIMILAR VOLUMES
Furthermore, we have proved that the null space of the linear operator of Piola-Kirchhoff stress history functional is the direct sum of the null space of linear operators for 6-D vector subspace N, and N,. Here we can naturally classify the fracture of isotropic material with memory into two types.