Accession Number : ADA305257

Title :   Characterization of the Interlaminar Shear Fatigue Properties of SMC R-50,

Corporate Author : DELAWARE UNIV NEWARK CENTER FOR COMPOSITE MATERIALS

Personal Author(s) : Wilson, Dale W.

PDF Url : ADA305257

Report Date : MAY 1980

Pagination or Media Count : 37

Abstract : The interlaminar shear fatigue behavior of the sheet molding compound SMC-R5O has been studied. A thick-laminate short beam shear test was employed to characterize S-N behavior for the material at 2l deg C and 9O deg C. The shear modulus (G sub xz) was determined at 2l deg C and 90 deg C and the effect of fatigue on modulus at both test temperatures is discussed. SEM and optical photomicrographs of untested and fatigued specimens were studied to assess the relationship between material microstructure and the observed fatigue results for strength and modulus. The experimental evidence suggests that the fatigue life for this material is determined by a flow criticality failure mechanism, not cumulative damage. The interlaminar shear fatigue behavior of the sheet molding compound SMC-RSO has been studied. A thick-laminate short beam shear test was employed to characterize S-N behavior for the material at 2l deg c and 9O0C. The shear modulus (Gxz) was determined at 2l deg C and 90 deg c and the effect of fatigue on modulus at both test temperatures is discussed. SEM and optical photomicrographs of untested and fatigued specimens were studied to assess the relationship between material microstructure and the observed fatigue results for strength and modulus. The experimental evidence suggests that the fatigue life for this material is determined by a flow criticality failure mechanism, not cumulative damage. (MM)

Descriptors :   *LAMINATES, *FIBER REINFORCED COMPOSITES, OPTICAL PROPERTIES, FIBERGLASS, MICROSTRUCTURE, DAMAGE, SHEAR MODULUS, STIFFNESS, CARBON FIBERS, STRENGTH(MECHANICS), SHEAR STRESSES, LIGHTWEIGHT, FATIGUE(MECHANICS), FAILURE(MECHANICS), PHOTOMICROGRAPHY.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE