A differential CDM model for fatique of unidirectional metal matrix composites

Conference · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7228783

Arnold, S M; Kruch, S

A multiaxial, isothermal, continuum damage mechanics (CDM) model for fatigue of a unidirectional metal matrix composite volume element is presented. The model is phenomenological, stress based, and assumes a single scalar internal damage variable, the evolution of which is anisotropic. The development of the fatigue damage model, (i.e., evolutionary law) is based on the definition of an initially transversely isotropic fatigue limit surface, a static fracture surface, and a normalized stress amplitude function. The anisotropy of these surfaces and function, and therefore the model, is defined through physically meaningful invariants reflecting the local stress and material orientation. This transversely isotropic model is shown, when taken to it's isotropic limit, to directly simplify to a previously developed and validated isotropic fatigue continuum damage model. Results of a nondimensional parametric study illustrate (1) the flexibility of the present formulation in attempting to characterize a class of composite materials, and (2) the capability of the formulation in predicting anticipated qualitative trends in the fatigue behavior of unidirectional metal matrix composites. Also, specific material parameters representing an initial characterization of the composite system SiC/Ti 15-3 and the matrix material (Ti 15-3) are reported.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
• OSTI ID: 7228783
• Report Number(s): N-92-31505; NASA-TM--105726; E--7128; NAS--1.15:105726; CONF-921110--; CNN: RTOP 510-01-50
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALLOYS
ANISOTROPY
CARBIDES
CARBON COMPOUNDS
COMPOSITE MATERIALS
DAMAGE
ELEMENTS
FATIGUE
FLEXIBILITY
FRACTURING
ISOTROPY
MATERIALS
MATHEMATICAL MODELS
MATRIX MATERIALS
MECHANICAL PROPERTIES
METALS
SCALARS
SILICON CARBIDES
SILICON COMPOUNDS
TENSILE PROPERTIES
TITANIUM ALLOYS