Accession Number : ADA019195

Title :   Crack-Length Determination for the Compact Tension Specimen Using a Crack-Opening-Displacement Calibration-Comparison of COD Measured Graphically and from the Gage Output.

Descriptive Note : Final rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Sullivan,A. M.

Report Date : 10 DEC 1975

Pagination or Media Count : 18

Abstract : To implement the increasing trend toward automated testing procedures, crack-length measurement during fatigue crack-growth-rate testing was determined using a COD gage technique. Data were analyzed both graphically and using the gage output measured in millivolts. To compensate for nonlinearity in the load-vs-COD traces, it was found necessary to sample differences in the load millivolt readings to produce smooth da/dN-vs-deltaK curves agreeing with those determined from graphical analysis of crack length. (Author)

Descriptors :   *Crack propagation, *Measuring instruments, *Pressure gages, *Fatigue tests(Mechanics), Calibration, Cracks, Cracking(Fracturing), Graphics, Curve fitting, Sampling, Experimental data, Automatic, Test equipment

Subject Categories : Test Facilities, Equipment and Methods
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE