Design and Manufacture of Hybrid Composite Leaf Spring

Abstract

ABSTRACT In order to have best performance of leaf spring, a study was conducted to replace the conventional steel leaf spring that used in vehicle by composite materials. This thesis focused on describe about design and analysis of hybrid composite leaf spring. A rear leaf spring for a "Toyota" is regarded for this purpose, and three materials are employed to fabricate the leaf springs. The matrix material was epoxy, while the reinforced materials were E-glass and carbon. Composite materials have a good corrosion resistance, a high strength to weight ratio, and high elastic strain energy storage capacity. So aim of this research is to investigate the structural properties of a hybrid leaf spring which made of (95% Epoxy with 5% carbon), (95% Epoxy with 5%glass fiber), and (95% Epoxy with 5% of hybrid composite 2.5% of carbon and 2.5% of glass fiber). In this study, Hand Lay-up technique was used in the fabrication of leaf spring due to its advantages (low cost tooling and simplest method) over the other methods. The effectiveness of the proposed composite leaf spring was evaluated by implementing the mechanical tests, which were Tensile, Impact, Hardness, Fatigue, Damping and Flexural. The experimental results recorded an improvement in the mechanical properties when the reinforcing fibers are used as well as the best results were obtained by hybrid reinforcement. Finite Element method was employed based on ANSYS software to simulate the leaf spring part. The linear isotropic model was chosen to determine stresses, deformations, and fatigue life when an internal static load is applied. Finally, the results proved that the hybrid composite materials have the ability to carry the load-applied leaf spring without failure and with minimum deflection and long fatigue life