Accession Number : ADA330856

Title :   Constitutive Modeling of Metal Matrix Composites Under Cyclic Loading

Descriptive Note : Final rept. 1 Sep 92-31 Dec 96

Corporate Author : LOUISIANA STATE UNIV BATON ROUGE DEPT OF CIVIL AND ENVIRONMENTAL ENGINEERING

Personal Author(s) : Voyiadjis, George Z. ; Echle, Rainer

PDF Url : ADA330856

Report Date : 08 MAY 1997

Pagination or Media Count : 156

Abstract : A micro-mechanical cyclic/fatigue damage model is developed for metal matrix composites. The model is based on thermodynamical principles within the framework of continuum damage mechanics and employs physical principles of damage behavior in metal matrix composites. A micro-mechanical approach is used in the sense that the overall material behavior is predicted by modeling the material behavior of the individual constituents. The Mori-Tanaka method is employed as a homogenization procedure. Individual anisotropic damage variables in the form of second order tensors are used for each of the constituents to allow for the modeling of appropriate damage and failure mechanisms in the composite. Individual damage initiation and evolution equations are developed for each constituent where physical principles of the damage mechanisms observed in experiments are considered. Damage mechanisms such as debonding and delamination are represented through individual damage tensors. The overall damage in the composite is obtained based on the individual damage tensors by means of the employed homogenization procedure. The elasto-plastic constitutive equations incorporate the influence of damage through the definition of the so-called damage effect tensors. A numerical implementation of the model is used to simulate cyclic/fatigue damage in metal matrix composites. Comparison of the results from the numerical simulations with experimental data show good agreement and substantiate the capabilities of the model.

Descriptors :   *METAL MATRIX COMPOSITES, *FATIGUE(MECHANICS), STRESS STRAIN RELATIONS, DAMAGE, FINITE ELEMENT ANALYSIS, MODULUS OF ELASTICITY, TENSORS, MICROMECHANICS, CYCLIC LOADS.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE