Photoelastic Measurement of Residual Thermomechanical Stress in SiC-Reinforced Glass Composites

Residual thermomechanical stresses in a Nicalon® SiC/7740 glass composite system were measured directly. Residual stresses for both single‐tow and two‐dimensional cloth‐reinforced samples were completely described via a digital microphotoelastic technique. Normal stresses approaching 4 MPa were observed in this composite system that had a thermal expansion coefficient mismatch of only 1.8%. The advantages of using this direct, full‐field technique over other theoretical and composite model approaches are also discussed.