RESIDUAL THERMAL-STRESSES IN A FILAMENTARY SIC AL COMPOSITE/

Residual stresses in a silicon carbide/aluminum (SiC/Al) composite int roduced by the cooling process were investigated. The large mismatch o f the coefficients of thermal expansion (CTE) between the silicon carb ide (SCS-2) fiber and 6061 aluminum matrix tends to produce high resid ual stresses so that plastic flow of the matrix is inevitable during c ool down. The elastoplastic behavior of the composite material was stu died. The analysis is based on the successive approximation scheme wit h the Prandtl-Reuss plastic flow model and von Mises criterion. The th ree-dimensional state of residual stress in the fiber and matrix was c omputed. It was found that plastic flow of the matrix relieves the res idual stresses in both fiber and matrix. In addition, the longitudinal stress-strain curve at room temperature under uniaxial tension and th e thermal strain-temperature relationship of the composite were predic ted and compared with experimental results.