ISSN: 1546-962X
Page Count: 14

A Physics-Based Predictive Model for Fracture Toughness Behavior
Natishan, ME
President, Phoenix Engineering Associates, Inc., MD

Wagenhofer, M
Graduate Research Assistant, Mechanical Engineering Department, University of Maryland, MD

Rosinski, ST
Program Manager, Electric Power Research Institute, NC

Abstract

Using the Zerilli-Armstrong (ZA) constitutive model for BCC materials and a combined strength-strain model of fracture, a physics model suitable for predicting the fracture toughness transition behavior of ferritic steels has been developed. The model predicts an exponential dependence of the plastic work on temperature and thus is comparable to the exponential dependence of plastic work predicted by Wallin et al. for the Master Curve. Exploring the limits of applicability of the ZA equation used as the basis for this model provides the information required to firmly establish the limits of material condition applicability of the Master Curve. Calculations based on limited data provide validation of the proposed model. The models' ability to predict shifts in transition temperature with irradiation and its application to RP vessel integrity assessment will also be discussed.

Keywords:
cleavage fracture, steels, transition temperature, dislocation mechanics, characteristic distance

Paper ID: JAI10614
DOI: 10.1520/JAI10614
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