Micro-mechanics of crack initiation

✍ Scribed by Jean Lemaitre

• Publisher: Springer Netherlands
• Year: 1990
• Tongue: English
• Weight: 602 KB
• Volume: 42
• Category: Article
• ISSN: 1573-2673
• DOI: 10.1007/bf00018615

✦ Synopsis

Prior to the crack initiation, damage is most often localized at a scale below the size of the classical representative volume element of the continuum mechanics. This allows the stress and strain analyses in a component to neglect the strain-damage coupling at macro-scale. At the micro-scale, this coupling plays a very important role which can be emphasized by a two scale element of an elastoplastic damaged microelement embedded in an elastic or elastoplastic macro-element. The Lin-Taylor hypothesis of strain compatibility allows the determination of the damage at micro-scale by solving the coupled constitutive equations for a given macro-strain history. It is shown how this model may be cast in the form of a post-processor of a finite element code and how a simple damage law coupled with strain constitutive equations replicates the main features of ductile or creep crack initiation, low cycle and high cycle fatigue for the case of a three-dimensional state of stress.