Authors
Johnson JC; Hustrulid WA
Source
Proceedings of the 2009 SEM Annual Conference, June 1-4, 2009, Albuquerque, New Mexico. Bethel, CT: Society for Experimental Mechanics, Inc., 2009 Jun; :1-12
Abstract
This paper presents a new experimental test procedure, the Hustrulid bar (HB), that combines aspects of two classic dynamic experiments, the Hopkinson bar and the split-Hopkinson pressure bar (SHPB) or Kolsky bar (KB). In the HB test, the specimen and transmission bars of the SHPB test where replaced by one long specimen bar. Strain gages attached at various positions along the length of the specimen bar permit a careful evaluation of the decay of strain under low, moderate and high impacts by the striker-incident bar combination. For low impact velocities, the peak strain levels in the specimen bar are elastic. As the velocity of impact is increased, an upper elastic strain limit is reached. As the striker bar velocity is further increased, high strain levels are produced in the specimen bar in the zone near the interface and damage results. The use of a long specimen bar permits the decay of strain to be separated into these damaged and un-damaged zones. In a high velocity impact test, for example, the decay of strain is greatest near the interface and then transistions into the elastic limit strain. The observed transition strain can be converted into the unconfined dynamic compressive strength using the Young's modulus of the material. The HB test was used to study four solids; a reference metal (aluminum 7075-T6) and three brittle materials (Indiana limestone, Vanga granite and concrete). This paper describes the apparatus and the data reduction procedure and presents the results.
Keywords
Mining-industry; Rock-mechanics; Geology; Underground-mining; Safety; Safety measures; Laboratory testing; Concretes
Contact
Jeffrey C. Johnson, NIOSH Spokane Research Laboratory 315 E. Montgomery, Spokane, WA 99207
Document Type
Conference/Symposia Proceedings
Source Name
Proceedings of the 2009 SEM Annual Conference, June 1-4, 2009, Albuquerque, New Mexico
