SEDL / STP / STP995V1-EB / STP26781S

An Advanced Procedure for J-R Curve Testing Using a Drop Tower

Joyce, JA
Professor of Mechanical Engineering, U.S.,

Hackett, EM
Research engineer, David Taylor Naval,

Pages: 20    Published: Jan 1988

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Abstract

An improved method to obtain J-R curves from drop-tower fracture mechanics specimens is described in detail. New features include aluminum absorbers to smooth the load versus time record, a double-capacitance gage to locate the crack initiation point, and an analytic key curve to obtain the J-R curve from a test on a single full-size fracture mechanics specimen. The absorbers are shown to slow the initial loading rate but not to affect the displacement rate near crack initiation or during the ductile tearing portion of the drop test.

Drop-tower J-R curves are obtained for a 3% nickel structural steel and compared with static results and results obtained by earlier test methods.