Accession Number : AD0751981

Title :   Fracture Mechanics Studies of Composite Systems.

Descriptive Note : Annual rept. no. 2, May 70-Jun 71,

Corporate Author : LEHIGH UNIV BETHLEHEM PA INST OF FRACTURE AND SOLID MECHANICS

Personal Author(s) : Sih,G. C. ; Hilton,P. D. ; Badaliance,R. A. ; Shenberger,P. S. ; Villareal,G.

Report Date : JUN 1971

Pagination or Media Count : 192

Abstract : A combined theoretical and experimental research program for investigating the application of fracture mechanics to composite systems is carried out. Preliminary results are presented which include the development of two fiber reinforced composite crack models, one with a low-fiber volume fraction and the other a high fiber volume fraction, and corresponding experimental data. The qualitative features of the theoretical prediction are in agreement with the experimental data indicating that there exists an optimum fiber volume fraction for which the composite achieves maximum fracture toughness. Tests were performed on uni-directional fiber reinforced composites with the crack running parallel to the fibers. For this arrangement, the current theory of fracture mechanics is shown to apply with good accuracy for FRP/epoxy composites. This is accomplished by performing two independent fracture tests the results of which are checked by an analysis of the crack system. A more elaborate analytical model is required for studying the graphite fiber/epoxy composite. (Author, modified-PL)

Descriptors :   (*COMPOSITE MATERIALS, FRACTURE(MECHANICS)), LAMINATES, CRACKS, DEFECTS(MATERIALS), FIBERS, STRESSES, LOADS(FORCES), BONDED JOINTS, REINFORCING MATERIALS, GLASS TEXTILES, CARBON FIBERS, EPOXY RESINS, ANISOTROPY, NUMERICAL ANALYSIS

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE