Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Maximum-load predictions in the Dugdale model using critical CTOA criterion

Journal Article · · Journal of Testing and Evaluation; (United States)
OSTI ID:5729591
 [1]
  1. Chung Ang Univ., Seoul (Korea, Republic of). Dept. of Mechanical Engineering

An engineering method of elastic-plastic fracture analysis is suggested for plane-strain specimens under tension. The condition for an increment of crack extension is set by a critical increment of crack tip opening displacement (CTOD). The CTOD increment divided by the incremental crack extension is a critical crack tip opening angle (CTOA), assumed to be constant for a material of a given thickness, characterizing the tearing resistance of material. Based on a finite-element analysis of crack tip deformation, a load term in the CTOD equation of the Dugdale strip yield model is modified to accommodate large and small scale yielding, for which cohesive stress in the strip is assumed greater than that for the plane-stress model. Approximate generalization of the Dugdale model is suggested for finite-size specimens. A definition of CTOD is reviewed with a round and sharp crack tip. In a successive application of the CTOA is reviewed with a round and sharp crack tip. In a successive application of the CTOA criterion at a current extending crack tip, the integration of the incremental crack extensions and load increments after fracture initiation gives a relationship in which a maximum load is either a peak load or a limit load on an unbroken ligament. Material constants are evaluated so that the calculated loads agree with test loads at each crack extension. The proposed method is applied to various specimens of 304 stainless steel for which test data are available.

OSTI ID:
5729591
Journal Information:
Journal of Testing and Evaluation; (United States), Journal Name: Journal of Testing and Evaluation; (United States) Vol. 21:6; ISSN JTEVAB; ISSN 0090-3973
Country of Publication:
United States
Language:
English