Assistant professor of mechanical engineering, U.S. Naval Academy, Annapolis, Md.
Head, David W. Taylor Naval Ship Research and Development Center, Annapolis Laboratory, Annapolis, Md.
Pages: 18 Published: Jan 1979
A computer interactive unloading compliance single-specimen JIc test procedure has been developed. This procedure utilizes an on-line minicomputer to analyze digitized load-displacement data during testing. Unique values of JI and crack length are determined from compliance measurement on short unloadings along the load displacement record. The test procedure is presented in detail and analysis procedures are discussed.
Three tasks which demonstrate the validity and utility of the computer interactive test method are discussed. Results for single-specimen and multiple-specimen tests are presented for HY 130, 10Ni steel, 17-4PH steel, Ti-7Al-2Cb-1Ta, and Ti-6Al-4V which show close correspondence between the two methods. Tests on 17-4PH steel compact tension specimens with various thicknesses and crack lengths are summarized and dimensional effects on JIc and the J-Δa resistance curve slopes are discussed. Finally, tests on HY 130 specimens with various notch root radii demonstrate effects of notch acuity on JIc.
elastic-plastic fracture, toughness testing, single-specimen tests, multiple-specimen tests, computer interactive testing, high-strength steels, titanium alloys, specimen geometry effects, notch acuity, unloading compliance test method, crack propagation
Paper ID: STP35843S