Journal Published Online: 01 January 1980
Volume 8, Issue 1

Computer-Controlled Stress Intensity Gradient Technique for High Rate Fatigue Crack Growth Testing

CODEN: JTEVAB

Abstract

An automated test system utilizing a computer for data acquisition and machine control was used to obtain crack growth rate data from 2.5 × 10−8 to 2.5 × 10−6 m/cycle (1 × 10−6 to 1 × 10−4 in./cycle) on a compact type specimen. The crack length was monitored continuously by using the elastic compliance technique, enabling the stress intensity K to be increased according to the equation ΔK = ΔK exp [C(aa0)] (where a0 and a are the initial and instantaneous crack lengths and C is a test variable). Crack growth data were obtained on a Ni-Cr-Mo-V rotor steel by using both different, programmed K gradients and the more conventional constant-load-amplitude method where the stress intensity increases as a function of increasing crack length. Excellent agreement was observed between the two test procedures.

Author Information

Donald, JK
Del Research Division, PSC Professional Services Group, Inc., Hellertown, Pa.
Schmidt, DW
Del Research Division, PSC Professional Services Group, Inc., Hellertown, Pa.
Pages: 6
Price: $25.00
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Details
Stock #: JTE10588J
ISSN: 0090-3973
DOI: 10.1520/JTE10588J