Design, Analysis and Comparison between the Conventional Materials with Composite Material of the Leaf Springs

Abstract

The automobile industry has shown increased interest in the replacement of steel springs with fiberglass composites leaf spring due to high strength to weight ratio. The main aim of the project is to find the effects of replacement of the leaf spring and composite leaf spring made of E-Glass Epoxy is carried out. Comparing the load carrying capacity, stresses, stiffness, contact stiffness, and weight savings of the composite leaf spring with that of steel leaf spring is performed. The design constraints are stresses and deflections. Finite element analysis with 3-D model of 9.525 mm thick leaf springs by introducing the contact pair in between the leafs a non-linear static analysis for the steel and composite material was done using ANSYS. The results are compared with the theoretical values and found in permissible limit. The analysis is performed in three phases. They are by varying the load applied on the leaf springs, by varying the normal penalty stiffness (FKN) of contact pair, by varying the thickness of the composite leaf spring. By varying the load and normal penalty stiffness the behavior of the steel and composite material multi-leaf spring is analyzed and the results are compared and holds good for composite material. Since the composite leaf spring at 9.525 mm thickness is having the higher stiffness than required value for the comfort ride, so it is modified by reducing the thickness of the leaf spring from 9.525 mm to 8 mm and analysis is carried out and compared. From this analysis it is found that the composite leaf spring had 29.981% lesser stresses, 12.951% of higher stiffness than that of the steel leaf spring. The obtained results for varying thickness of composite leaf spring compared to the steel leaf spring are satisfactory. Due to the thickness variation the weight reduced of 69.48% was achieved. It is found that the obtained natural frequency of 8 mm thick composite leaf spring is away from the road irregularity usually have maximum frequency (12Hz) therefore resonance will not occurs and it provides improved ride comfort.