5. Results and discussion
The finite element analysis has performed to know the stress behavior of steel spring and composite leaf spring. During the analysis, the range of load is applied from 1000 N to 5400N on spring and results of stress are described in Table 5.1.
By compared the result of the stress of steel spring and composite leaf spring material, it has observed that composite leaf spring has 38% less stress as compared to the steel spring as shown in fig. 5..It means that fatigue life composite leaf spring is more than steel spring. According to the Society of Automobile Engineering (SAE)[23] and Indian standard 1135 (1995)[24] recommends that fatigue strength of leaf spring should be more than 100000 cycles and less than 400 MPa. A fatigue life over 100000 cycles assures that road life of the spring will be more than 160000 km on the highway. The off-road running may reduce the life of the spring. So Finite element analysis shows that the stress range is very less than stress limit.