An experimental investigation into mechanical behavior of hybrid and nonhybrid composite semi-elliptical springs

This study introduces a new composite semi-elliptical suspension spring by utilizing fiber reinforced composite strength in principal direction instead of shear direction. Three types of composites were tested, namely, carbon/epoxy, glass/epoxy and glass/carbon/epoxy. A comprehensive experimental investigation of composite semi-elliptical suspension springs has been carried out. Typical behaviors of their compression, tension, torsion and cyclic tests are presented and discussed. The results showed that the fiber type and ellipticity ratio significantly influenced the spring stiffness. After 1.15 million fatigue cycles, composite semi-elliptical suspension spring’s useful stroke is reduced by only 2%. The relaxation of the composite elliptic spring found to be very sensitive to the compression rate.