SEDL / STP / STP905-EB / STP17402S

Fracture Testing With Arc Bend Specimens

Underwood, JH
U.S. Army Armament R&D Center, Watervliet, NY

Kapp, JA
U.S. Army Armament R&D Center, Watervliet, NY

Witherell, MD
U.S. Army Armament R&D Center, Watervliet, NY

Pages: 18    Published: Jan 1986

Download this paper for $25 PDF (256K)          View License Agreement
Abstract

A limited review of existing stress, stress intensity factor, and displacement analyses was compared with new work in order to select arc bend geometries appropriate for fracture testing. Results from the literature for rectangular and arc bend specimens were compared with finite element and boundary collocation results from the present work.

Two series of comparative tests were performed, one with arc specimens cut from a steel forging with outer-to-inner radius ratio of 2.5, the other from an aluminum cylinder with outer-to-inner radius ratio of 1.3. Fracture toughness tests, K^Ic, and J^Ic when appropriate, were performed with standard arc tension specimens and with three-point arc bend specimens with both arc and chord support.

Conclusions were drawn regarding the appropriate stress intensity factor, crack mouth displacement, and load-line displacement solutions for arc bend fracture specimens. Recommendations were offered for practical ranges of specimen geometry and for reliable test procedures.