Volume 2, Issue 6 (June 2005)
Notch-Root Elastic-Plastic Strain-Stress in Particulate Metal Matrix Composites Subjected to General Loading Conditions
Determining the stress and strain history at the point of highest stress concentration in particulate metal matrix composites (PMMCs) is complicated, particularly when they have a finite concentration of inclusions, the matrix material in the vicinity of the notch is elastic-plastic, and when multiaxial cyclic loads are applied to the component. In this paper, an analytical tool is developed to approximate notch root elastic-plastic strains and stresses in PMMC components subjected to multiaxial cyclic loads. The model consists of a set of linear relations that can be solved to estimate a notch root elastic-plastic strain and stress history in PMMCs from an elastic analysis. The model is developed using assumptions about notch root behavior, the incremental mean field theory, and the endochronic theory of plasticity. The model presented provides an easy to implement approximation to the otherwise rather complex non-linear problem. The analytical results are compared to the local strains, obtained using 3D image correlation technology, at the depth of a circumferential notch in a PMMC bar subjected to proportional and non-proportionally applied monotonic and cyclic axial-torsional loads. The results of the comparison show that the proposed model works well for the geometry and load paths considered.