1.1 ,This test method covers the procedure for the determination of the dry or wet (moisture conditioned) glass transition temperature (T_g) of polymer matrix composites containing high-modulus, 20 GPa (>, 3 ×, 10⁶ psi), fibers using a dynamic mechanical analyzer (DMA) under flexural oscillation mode, which is a specific subset of the Dynamic Mechanical Analysis (DMA) method.