Materials Selection Methods in the Design of Monocoque for a Fuel Efficient Concept Vehicle

Abstract

A multiple criteria decision methods (MCDM) using Complex Proportional Assessment (COPRAS), Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), and Cost per Unit Property were utilized to determine the best material in the design of monocoque for a fuel efficient vehicle. Specifically, the material properties being evaluated from the different alternative materials for the floorboard and body of an urban concept eco-car underwent necessary calculations based on the integration of the various material selection methods. The study showed that the glass fiber-reinforced polymer (GFRP) was the best floorboard material among other options from magnesium alloys, aluminium alloys, mild steel and carbon fiber-reinforced polymer (CFRP). The criteria considered in the calculation include the ultimate strength, yield strength, modulus of elasticity, density and cost. Moreover, the face sheet CFRP and honeycomb core sandwich combination, particularly the T700-Nomex honeycomb, was the best option for the car body. The properties being considered in this calculation were the maximum in plane stress (MIPS) of the face sheet material, the maximum shear stress of the core, the weight and the cost.