Accession Number : AD0878449

Title :   Dynamic Fracture Criteria of Homogeneous Materials.

Descriptive Note : Technical rept 8 May 68-15 Jul 70,

Corporate Author : STANFORD RESEARCH INST MENLO PARK CA

Personal Author(s) : Barbee, T. ; Seaman, L. ; Crewdson, R. C.

Report Date : NOV 1970

Pagination or Media Count : 292

Abstract : A method is described by which damage can be quantatively predicted in solid materials subjected to known shock loads. Damage, in this method, is treated as a new phase and predictive capabilities are attained by the measurement of the dependence of the growth and nucleation rates of damage on stress history. The steps of the method are (1) shock and recover specimens, (2) describe the size and spatial distributions of cracks, (3) achieve experimental control so that the cracks can be stopped in different stages of achieve experimental control so that the cracks can be stopped in different stages of growth, and (4) specify the macroscopic stress and time at stress experienced at any location in the specimen. Generally valid nucleation and growth laws of damage can be determined by correlation of the observed damage with the stress histories of the specimen. Quantitative predictions can then be made of damage caused by an arbitrary imposed stress history using these general nucleation and growth laws. The report describes experiments on several ductile materials (1060 aluminum, 1145 aluminum, and 2024-T81 aluminum), a brittle material (Armco iron), and several composite materials. (Author)

Descriptors :   (*FRACTURE(MECHANICS), ALLOYS), (*COMPOSITE MATERIALS, FRACTURE(MECHANICS)), STRESSES, DUCTILITY, BRITTLENESS, TENSILE PROPERTIES, CRACK PROPAGATION, IMPACT TESTS, HYDROSTATICS, NUCLEATION, DEFECTS(MATERIALS), IRON, MATHEMATICAL MODELS, COMPUTER PROGRAMS, QUARTZ.

Subject Categories : Laminates and Composite Materials
      Mechanics
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE