Single-Specimen Tests for JIc Determination—Revisited

Abstract

Since the development of the unloading compliance method, numerous improvements to this JIc and J-R curve testing procedure have occurred over the past five years. This paper presents a description of many of these test technique improvements along with the results of the improvements. Improvements in both mechanical and electrical systems are shown to greatly improve the reproducibility of the unloading compliance data. Computerization of the data reduction has led to a better understanding of the requirements necessary for an accurate J-versus-Δa R-curve.

A Numerical Investigation of Plane Strain Stable Crack Growth Under Small-Scale Yielding Conditions

“…They also present a model based on growth between equally-spaced inclusions which predicts a constant crack tip opening angle. J integral experimentation due to Clarke et al [13] and Griffis and Yoder [14] indicates a constant change of J with change of crack length following the blunting of an initially sharp crack.…”

“…A key objective of the numerical solutions, aside from the illumination of the stress and strain distributions accompanying growing cracks, is the investigation of possible macroscopic parameters which may be correlated with the "state" at the growing crack tip. Although the meaning of the J integral is unclear in the growing crack case, J is known to rise monotonically with crack advance, e.g., [13], and its use as a fracture predictor in the extending crack case is a possibility.…”

Beschreibung und Beurteilung gebräuchlicher Verfahren zur Ermittlung von JIc‐Werten für Reaktordruckbehälterstähle

“…Als brauchbarer Wert fur O! wurde 0,01 festgelegt (41). Derartige Werte erwiesen sich als geeignet bei Untersuchungen an ferritischen Stahlen, deren chemische Zusammensetzung derjenigen der ublichen Reaktorbaustahle entsprach.…”

“…Die Proben konnen unter Plungerpositionskontrolle in einer elektrohydraulischen ZerreiRmaschine mit geschlossenem Kreislauf belastet werden (41) Be-und Entlastungen erfolgen automatisch bei gleichbleibenden Geschwindigkeiten. Die Belastungsabnahme soll in keinem Fall mehr als 10% der errechneten Hochstlast ausmachen.…”