Accession Number : AD0804327

Title :   CRAZING AND YIELDING OF REINFORCED COMPOSITES.

Descriptive Note : Quarterly progress rept. no. 2, 1 Sep-1 Dec 66,

Corporate Author : DOUGLAS AIRCRAFT CO LONG BEACH CA AIRCRAFT DIV

Personal Author(s) : Noyes, J. V. ; Jones, B. H. ; Hernandez, L. A.

Report Date : 01 DEC 1966

Pagination or Media Count : 122

Abstract : Compression tests were performed on the three program resin systems; ERRA 0300/MPDA, EPON 828-1031/BDMA-MNA, and ERL 4221/HHPA-EMPOL 1022 in order to accurately determine their stress-strain characteristics throughout the elastic and plastic range. The flaw distribution theory for predicting unidirectional tensile strength was found to agree very accurately with published test results. A strength analysis for the general multi-layer, oriented filament composite has been formulated and programmed based upon the distortional energy failure criterion utilized by Tsai. It has been refined, however, to account for the differences in tensile and compressive properties encountered in fibrous composite materials. Expressions are also presented which pertain to the effects of thermal residual stresses and voids on the strength performance of the basic unidirectional layer. (Author)

Descriptors :   *FAILURE(MECHANICS)), (*REINFORCED PLASTICS, (*GLASS TEXTILES, COMPOSITE MATERIALS), (*EPOXY RESINS, COMPOSITE MATERIALS), TENSILE PROPERTIES, COMPRESSIVE PROPERTIES, SHEAR STRESSES, NOTCH SENSITIVITY, CRAZING.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE