NONCONSERVATIVE BEHAVIOR OF COMPOSITE MATERIALS.
Abstract
The axial loading solution for anisotropic filaments is an extension of the isotropic filaments solution included in AD-654 056. Numerical results are presented indicating that stresses in the transverse plane are lower than for isotropic filaments and that the simple 'rule of mixtures' approximations for predicting composite axial stiffness and major Poisson's ratio are valid for anisotropic as well as isotropic filament composites. Experimental studies included the determination of longitudinal shear strength and stiffness properties of unidirectional boron-epoxy composites. The solid rod torsion test as well as the plate twist test were used. Tension-zero-tension cyclic fatigue data for 0 deg unidirectional S glass-epoxy composites are presented along with additional data concerning the influence of surface grinding on the mechanical properties of 90 deg unidirectional specimens. An analytical investigation of the linear viscoelastic behavior of composite materials is made by the solution of the problem of a single elastic inclusion in an infinite viscoelastic matrix under transverse loading. Experimental data presented in the literature is evaluated and used in various approximate viscoelastic models for the epoxy resin matrix. Insights into the behavior of the periodic array of inclusions are drawn from the single inclusion solution with limitations noted. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1968
- Accession Number
- AD0666675
Entities
People
- Joseph M. Bloom