Files in this item



application/pdfSRS-603.pdf (1MB)
Structural Research Series 603PDF


Title:Constraint Effects on Fracture Toughness of Impact Loaded, Pre-cracked Charpy Specimens
Author(s):Koppenhoefer, K.C.; Dodds, Robert H., Jr.
Subject(s):Fracture toughness
Charpy specimens
Finite elements
Abstract:Impact loaded, pre-cracked Charpy specimens often play a crucial role in irradiation surveillance programs for nuclear power plants. However, the small specimen size (B = W = 10 mm) limits the maximum value of cleavage fracture toughness (Jc ) that can be measured under elastic-plastic conditions without loss of crack tip constraint. In this investigation, plane-strain impact analyses provide detailed resolution of crack-tip fields for impact loaded specimens. Crack-tip stress fields are characterized in terms of J-Q trajectories and the Toughness Scaling Model which is applicable for a cleavage fracture mechanism. Results of the analyses suggest deformation limits at fracture in the form of b >MJc/ao, where M approaches 25-30 for a strongly rate sensitive material at impact velocities of 3-6 m/ s. Based on direct comparison of the static and dynamic J-values computed using a domain-integral formulation, a new proposal emerges for the transition time, the time after impact at which inertial effects diminish sufficiently for simple evaluation of J using the plastic eta factor approach.
Issue Date:1995-06
Publisher:University of Illinois Engineering Experiment Station. College of Engineering. University of Illinois at Urbana-Champaign.
Series/Report:Civil Engineering Studies SRS-603
Genre:Technical Report
Sponsor:U.S. Nuclear Regulatory Commission. Office of Nuclear Regulatory Research. Division of Engineering.
Contract N00167-92-K-0038
Date Available in IDEALS:2009-11-13

This item appears in the following Collection(s)

Item Statistics