CRAZING AND YIELDING OF REINFORCED COMPOSITES.
Quarterly progress rept. no. 1, 1 Jun-1 Sep 66,
DOUGLAS AIRCRAFT CO LONG BEACH CA AIRCRAFT DIV
Pagination or Media Count:
Work has been accomplished toward establishing the foundation for the study of crazing and yielding in fiber reinforced composites. This was done by surveying pertinent literature in the field of micro and macro-mechanics of fibrous composites in order to pick the most suitable theoretical expressions for the strength and elastic behavior of this class of anisotropic material. Selected expressions for the elastic properties of the material have been modified to account for the effects of three-dimensional restraint on the basic fibermatrix analytical model. The expressions for the strength properties have been formulated based upon an analysis of the generalized state of stress and strain in the interfilament matrix zones. A strength analysis approach was selected which will permit the occurrence of crazing and yielding in the general multi-layer, oriented fiber laminate to be studied in terms of the fundamental properties of the constituent fiber and matrix materials. This test program encompasses tests of the matrix material only, tests of the uni-directional filament laminate, and tests of the multi-layer, oriented fiber laminate. The materials employed in the experimental tests will be S-994 glass fibers and epoxy resins.
- Laminates and Composite Materials