“…It is obtained that the helical composite spring with a BUR structure has the highest mechanical properties among the four types of helical composite springs, its failure load in compression approximately equals 3297 N and the spring constant is almost 160 N/mm. According to the result have been obtained, the helical composite spring with a rubber core can increase its failure load in compression by about 12%; while the spring with a braided outer layer can not only increase its failure load in compression by about 18%, but also improve the spring constant by approximately 16% [15]. Ekanthappa, J. et al studied on the fabrication and strength of glass fiber reinforced epoxy composite helical springs.…”