The effect of fiber orientation and stacking sequence on carbon/E-glass/epoxy intraply hybrid composites under dynamic loading conditions

This study investigated the dynamic mechanical properties of hybrid intraply carbon/E-glass epoxy composites with different orientations and stacking sequences under different loading conditions with increasing temperature. A neat epoxy and five various hybrid composites such as Carbon (0 degrees)/E-glass (90 degrees), Carbon (45 degrees)/E-glass (135 degrees), Carbon (90 degrees)/E-glass (0 degrees), Carbon/E-glass (alternating layer), and Carbon/E-glass (alternating layer 45 degrees) were manufactured. Three-point bending test and dynamic mechanical test were conducted to understand the flexural modulus and viscoelastic behavior (storage modulus, loss modulus, and loss tangent) of the composites. Dynamic mechanical test was performed with the dual cantilever method, at four different frequencies (1, 5, 10, and 20 Hz) and temperatures ranging from 30 to 150 degrees C. The experimental results of storage modulus, loss modulus, and loss tangents were compared with the theoretical findings of neat epoxy and various hybrid composites. The glass transition temperature (T-g) increased with the increase in frequency. A linear fit of the natural log of frequency to the inverse of absolute temperature was plotted in the activation energy estimation. The interphase damping (tan delta(i)) between plies and the strength indicator (S-i) of the hybrid composites were estimated. It was observed that the neat epoxy had more insufficient storage and loss modulus and a high loss tangent at all the frequencies whereas hybrid composites had high storage and loss modulus and a low loss tangent for all the frequencies. Compared with other hybrid composites, Carbon (90 degrees)/E-glass (0 degrees) had higher strength and activation energy. The result of reinforcement of hybrid fiber in neat epoxy significantly increases the material's strength and stability at higher temperatures whereas decreasing free molecular movement.