High Temperature Stress Assessment in SCS-6/TI-6A1-4V Composite Using NeutronDiffraction and Finite Element Modeling

摘要

Thermal Residual stresses (TRS) in a continuous silicon carbide fiber reinforced(35 vol. %) titanium matrix composite were measured using neutron diffraction (ND). The TRS were determined in the matrix andj7bers during heating from room temperature to 1170K. An elasto-viscoplastic finite element analysis was used to predict TRS by allowing matrix creep matrix and the thermal history followed during the course of ND measurements. The comparison of TRS between FEM predictions and ND measurements showed good agreement across the temperature region. At room temperature, axial and transverse stresses (parallel and perpendicular to the fibers) were in the ratio of about -3:1, both in the matrix and jiber phases, respectively. With increase in temperature the residual stresses relaxed linearly to approx. 900K, beyond which the stresses remained close to zero to 1170 K.