Date of Completion


Embargo Period



Dr. Richard Christenson, Dr. Michael Accorsi

Field of Study

Civil Engineering


Master of Science

Open Access

Open Access


Our nation’s deteriorating infrastructure demonstrates the need for a new class of multifunctional materials that alleviate the shortcomings of traditional materials. Conventional fiber-reinforced polymer (FRP) composites have served as an alternative material in civil structures for the past three decades. They offer high strength and stiffness, low weight, and corrosion resistance, however, lack ductility and the ability to absorb energy before failure.

To address these shortcomings for structural composites, research was conducted to investigate the capabilities of fiber hybridization. Varying volume fractions of thin steel reinforcement were introduced into typical glass fiber reinforced epoxy composites. This hybrid FRP may address the limitations by combining the best characteristics of metal and nonmetal fiber reinforcement and polymeric resin. Three different epoxy resins were tested to compare the strength and ductility in order to guide design of the composite specimens. Three different types of metal reinforcements were explored: 1) small-diameter ductile steel fibers, 2) fine wire steel mesh, and 3) thin perforated steel sheets. Non-hybrid and hybrid composite specimens were manufactured. Coupons with and without holes were tested under monolithic and half-cyclic tensile loading to obtain stress-strain relationships, hysteresis behavior, and failure mechanisms. Failure specimens were examined to understand the damage progression due to the interaction of glass and steel reinforcement. A bilinear hysteresis model was used to predict hybrid fiber reinforced composite cyclic behavior. Incorporating steel fibers into glass/epoxy composites may offer a significant improvement in energy absorption prior to failure and material re-centering capabilities, while maintaining a high strength-to-weight ratio.

Major Advisor

Dr. Arash Esmaili Zaghi