Analysis of a Novel Fracture Toughness Testing Geometry

Abstract

Approved for public release; distribution is unlimited.ii REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY)December 2012 REPORT TYPE ARL-TR-6266 SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S) SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTES ABSTRACTComputational analyses were conducted on novel fracture toughness specimens known as "butterfly" specimens, which were developed at the U.S. Army Research Laboratory. A three-dimensional (3-D), J-integral technique was established and validated against published results for a simple geometry. The technique was then used to generate a stress intensity factor function for a range of geometries for the butterfly specimen. A displacement-based description of the load on the specimen was developed that removes the need to accurately determine the specimen/platen frictional effects, and 3-D analyses were conducted to elucidate specimen thickness effects and their implications on surface measurements that are taken during experimental studies. iii