The Structure of the Near Tip Field during Transient Elastodynamic Crack Growth
Abstract
The process of dynamic crack growth in a nominally elastic material under conditions of plane strain or plane stress is considered. Of particular concern is the influence of the transient nature of the process on the stress field in the immediate vicinity of the crack tip during nonsteady growth. Asymptotically, the crack tip stress field is square root singular at the crack tip, with the angular variation of the singular field depending weakly on the instantaneous crack tip speed and with the instantaneous stress intensity factor being a scalar multiplier of the singular field. However, for a material practice at a small distance from the moving crack, the local stress field depends not only on instantaneous values of crack speed, stresses and stress intensity factor, but also on the past history of these time-dependent quantities. Within some small region near the tip, the two dimensional elastic field must give way to region of inelastic deformation. If this inelastic zone is completely surrounded by a stress intensity factor field, then it is assumed that fracture will begin when the value of stress intensity factor has been increased to a material specific value, the fracture toughness of the material. When the stress intensity factor idea is applied to the case of a through the thickness cracking of plates, the restrictions become more severe if the process is associated with a two dimensional state of plane stress.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1991
- Accession Number
- ADA236889
Entities
People
- A. J. Rosakis
- L. B. Freund
Organizations
- California Institute of Technology