Optimization and analysis of Sic reinforced copolymer blend composite structural springs

Abstract

The design of lightweight leaf springs plays a crucial role in reducing fuel consumption and improving vehicle comfort by minimizing road shock transmission and vibration. Composite materials have shown great potential in significantly reducing leaf spring weight. epoxy, being a desirable thermoset polymer widely used in various applications such as electrical devices, ships and automobiles, exhibits limitations in terms of brittleness, fracture resistance and impact strength. To overcome these drawbacks while preserving its beneficial properties, epoxy can be blended with other polymers and reinforcements. In this study, polysulfide (PS) was selected as a suitable solution to enhance epoxy brittleness, offering an effective yet underutilized approach. Furthermore, the incorporation of silicon carbide (Sic), known for its superior characteristics, aimed to further enhance the mechanical properties of the epoxy-PS copolymer blend. The microstructural analysis was inspected using Fourier transform infrared. The blending and reinforcement process followed a Taguchi L8 static design to evaluate the impact of different composite blending percentages (represented as input factors) on leaf spring tensile strength, damping properties, impact resistance and hardness (represented as responses). The responses were analyzed using S/N ratios, ANOVA, main effect plots and interaction plots, while regression equations were employed to predict the responses under varying factors. The analysis demonstrated a robust model for manufacturing leaf springs. Experimental results indicated a 7.4% reduction in hardness with the addition of PS polymer. Conversely, reinforcing the epoxy-PS copolymer with 10–20% wt. of Sic resulted in a 3–5% increase in hardness. The natural frequency of the composite exhibited a gradual decrease upon the incorporation of PS and Sic. Evaluating the damping ratio revealed that the maximum value was achieved when the epoxy-PS copolymer was reinforced with 20% Sic. Additionally, while the copolymer blend displayed the greatest logarithmic decrement, epoxy exhibited the highest damping frequency.