Accession Number : AD0877614

Title :   The Time Dependent Mechanical Behavior of Composite Materials.

Descriptive Note : Summary rept. 1 Mar 69-1 May 70,

Corporate Author : TRW EQUIPMENT LABS CLEVELAND OH MATERIALS TECHNOLOGY DEPT

Personal Author(s) : Menke, George D. ; Toth, Istvan J.

Report Date : JUN 1970

Pagination or Media Count : 108

Abstract : The fatigue and creep behavior of selected unidirectional and cross-plied composites of boron filament reinforced 6061 aluminum has been investigated. Selection of two filament contents and two matrix conditions was based on the tensile strength and filament breakage results of a series of tests of 30, 40, 50, 60, and 73 v/o composites, with variables of cross-plying and processing conditions. Room temperature tension-tension fatigue experiments were conducted on 40 and 60 v/o B-6061 Al specimens, with four different unidirectional reinforcement orientations, two cross-ply configurations and in both annealed and modified T6 heat treatments. Off-axis unidirectional and cross-ply configurations exhibited significantly lower fatigue properties, with EL/UTS ratios reduced to 0.5 to 0.65. The creep bend behavior investigation shows that the flexural stress-rupture properties are controlled by the rate of shear creep of the matrix, as influenced by the ability of the filaments to be loaded. This conclusion is backed up by the room temperature forming properties of the composite specimens. (Author)

Descriptors :   *ALUMINUM ALLOYS), *BORON), (*COMPOSITE MATERIALS, (*REINFORCING MATERIALS, MECHANICAL PROPERTIES, CREEP, FATIGUE(MECHANICS), TENSILE PROPERTIES, TEST METHODS, ELECTRON MICROSCOPY, SURFACE PROPERTIES, FIBERS, MODULUS OF ELASTICITY.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE