Load Transfer Characteristics and Residual Stresses in Composite Material Systems.
Abstract
In this study, the load transfer characteristics of a broken fiber are investigated. The problem consists of a cylindrical fiber that is embedded into a matrix material. The fiber axis is assumed to coincide with the z-axis and a crack is assumed to be present on the plane z =0 and for r < a. Far away from the crack, the fiber is subjected to uniform external load of sigma sub 0. Moreover, adjacent to the crack and along the interface, the matrix and fiber surfaces are assumed to slide along the interface length -c < z < c, where there is a nonuniform friction. On the other hand, perfect bonding is assumed to prevail all along the remarking interface. Residual stresses due to curing and thermal stresses due to differences between the thermal expansion coefficients of the matrix and fiber may have a major effect on the microstresses within a composite material system and must be added to the stresses induced by the external mechanical loads. Such microstresses are often sufficient to produce microcracking even in the absence of external mechanical loads, example during the cooling process. In this report a few selected results are presented for a material system consisting of SIC-6 cylindrical fibers which are periodically embedded into a plate matrix consisting of beta21 material. The results are based on a linear elastic-micromechanics model which provides the stress profiles due to (1) a uniform load perpendicular to the direction of the fibers and (2) due to a thermal expansion mismatch.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1997
- Accession Number
- ADA326167
Entities
People
- E. S. Folias
Organizations
- University of Utah