Composite materials are widely used for aircraft, satellites, and other structures due to
their good mechanical and thermal characteristics such as high specific stiffness and strength, a low
coefficient of thermal expansion, and good heat-resistance. However, for the use of composites
under high temperature, their material properties must be measured and verified at high
temperatures. In this study, the material properties of T700/Epoxy were measured through a tension
test of composite specimens with an embedded fiber Bragg grating sensor in a thermal chamber at
temperatures of room temperature, 100 oC, 200 oC, 300 oC, and 400 oC. The effects of an optical
fiber on the material properties of the composites were investigated through a pre-test of embedding
an optical fiber. Finally, the material properties of composites, parallel to and perpendicular to the
reinforcing fiber, were successfully shown to vary according to increases in the temperature.