Accession Number : ADA307831

Title :   A Study of Stiffness, Residual Strength and Fatigue Life Relationships for Composite Laminates.

Descriptive Note : Final rept.,

Corporate Author : LOCKHEED-CALIFORNIA CO BURBANK

Personal Author(s) : Ryder, J. T. ; Crossman, F. W.

PDF Url : ADA307831

Report Date : OCT 1983

Pagination or Media Count : 574

Abstract : The purpose of this research investigation was to explore, in both a qualitative and quantitative fashion, the relationship among stiffness, strength, fatigue life, residual strength, and extent of damage of unnotched, graphite/epoxy laminates subjected to tension loading. The study consisted of experimentation on a wide range of laminates involving detailed observations of damage development and progression and the correlation of this damage to stiffness, strength, and fatigue life. Damage states were analyzed and extensively mathematically modeled in order to delineate and understand the relationship among the measured variables. Enough understanding of the tension loaded case was developed to allow development of a proposed, simple procedure for calculating strain to failure, stiffness, strength, data scatter, and shape of the stress-life curve for unnotched laminates subjected to tension load.

Descriptors :   *FATIGUE LIFE, *STIFFNESS, *EPOXY LAMINATES, *GRAPHITE EPOXY COMPOSITES, STRESS STRAIN RELATIONS, MATHEMATICAL MODELS, LOAD DISTRIBUTION, DAMAGE, COMPOSITE MATERIALS, FINITE ELEMENT ANALYSIS, LOADS(FORCES), TENSILE STRESS, CRACKING(FRACTURING), FIBER REINFORCED COMPOSITES, ORIENTATION(DIRECTION), STRENGTH(MECHANICS), FAILURE(MECHANICS), DELAMINATION, TENSILE TESTERS, CYCLIC LOADS.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE