Investigation on the effects of changing automotive vehicles leaf springs from steel to hybrid polymer composite leaf springs

Abstract

Leaf Springs find vast applications in different types of mechanical systems. In spite of lot of research, spring steel leaf springs find a lot of applications in all types of heavy vehicle. Weight reduction is one of the present trends in the automotive vehicles and many researchers worked on better materials and design optimization for the same. Composite leaf springs represent some application of composite materials in the field of automotive lightweight materials. This paper is focused to design a natural fibre reinforced hybrid polymer composite mono leaf parabolic spring to replace the existing steel multi-leaf semi-elliptical spring in an attempt of reducing the unsprung mass and investigate its stiffness characteristics by different methods. The spring so designed is analysed for its deflection and hence for its stiffness, by Virtual work method, whose complex integral was solved numerically by Gauss Quadrature. Along with analyzing the stress pattern and making sure the failsafe condition is met, ANSYS is used to construct a model using Solidworks and then use that model to compute the deflection. In the end, three genuine prototypes of the springs were made utilizing match board wooden moulds and the hand lay-up process. These springs were then put through a static load test in a Universal Testing Machine. According to the findings, the spring that is developed to take the place of the present spring will likely have the requisite dynamic and vibration characteristics, and it will also be 83% lighter; as a consequence, it will be suggested as a very excellent replacement. After that, a harmonic disturbance was applied to the springs, and the resulting deflection was analysed. A test rig was built for this specific purpose, and the spring was put under harmonic forcing.