Design of Copolymer-Reinforced Composite Material for Leaf Springs Inside Elastic Suspension System of Light-Duty Trucks

The growing request regarding the comfort of passengers, saving the environment by using new materials to lower fuel consumption, as well as exhaust emissions of motor vehicles, is the main cause of searching for new and high-performance products in this area. Composite materials are the most promising technology. The composite leaf springs, applying as part of the elastic suspension system with high strength, load-carrying capacity, and lightweight, are one of the possible manners to achieve those goals inside of vehicles used for the carriage of goods. As an example, inside the manuscript, fabricated epoxy thermoset is blended with 10-50 wt.% of polysulfide rubber composites and reinforced with 10 wt.% of alumina powder. The characteristics of the copolymer composite blend were studied by performing ASTM mechanical tests, including tensile strength, impact strength, hardness, and damping ratio tests. Experimental test results showed that tensile strength, natural frequency, and damped ratio were decreased when the polysulfide rubber percent increase in contrast to tensile strength, which showed a noticeable decrement. From the second side, the reinforcement on the basis of alumina powder caused a weighty increase in tensile strength and natural frequency with a good improvement in deformation strength. Impact strength and damping ratio were maximized when alumina powder was added increasingly, while this increase was contrary to, causing a decrease in the hardness of reinforcement. The experimental results were optimized using the statistical methods. Design of the experiment and linear regression model used to select the most appropriate mixture inside the proposed composite material for leaf springs manufacturing. Finally, validation of the model was realized by application of the statistical method of analysis of variance and probability plots (normal distribution). The regression equations of tensile and impact strength, hardness, and damping ratio test results showed that the proposed composite material is suitable to be applied for manufacturing the leaf springs considering loadings and working conditions during exploitation of such vehicles in traffic. Finite element analysis on the basis of a finite element model of composite material was performed using SolidWorks Simulation 22. Mechanical software ANSYS 2022 R1 was used to study the mechanical properties of the leaf spring model fabricated of the proposed composite material. Finite element analysis results interpreted and showed significant reduction in leaf spring weight with very good mechanical properties considering tensile and impact strength, hardness, and damping ratio when using the proposed copolymer-reinforced composite material.