Vibration analysis of metal – polymer sandwich structure incorporated in car bonnet

Abstract

The weight of the car material plays an important role in its performance in terms of fuel efficiency, speed and smoke emission. Especially in hybrid electric vehicles, lightweight materials are important for balancing the weight of its electrical components and also to enhance vehicle speed on account of its comparative low mileage. Nowadays, aluminium, magnesium and Carbon Fibre Reinforced Composites (CFRP) were introduced in making of car body panels since those materials can improve its performance. Yet the material costs, fibre orientation and fabrication techniques in case of CFRP in mass production remains a question. Also, the interior of the car panels was filled with vibration barriers or isolators with considerable thickness which can also add weight to the car. Hence a sandwich structure is presented in this work where the polyurethane foam of higher thickness (core) is bonded between two thin metallic face sheets (skin). The polyurethane foam was chosen as the core because of its low density, porosity and viscoelastic behaviour where it can provide better damping capabilities. Hence, the foam can also help in reducing the volume of internal vibration isolators. Since the car bonnet receives the vibration from sources like aerodynamic exposure to air during travel and mechanical movements within the vehicle (engine operation), it was chosen as the subject for vibration analysis.

Research Progress on Characterization and Regulation of Forming Quality in Laser Joining of Metal and Polymer, and Development Trends of Lightweight Automotive Applications

“…The bending stiffness and torsional stiffness of the composite hood reached 80% of those of the original steel front cover, and the mass weight was reduced by 30%. Deepak et al [23] proposed a kind of "metal-plastic-metal" sandwich structure automobile hood, based on a material combination of steel, aluminum, and polyurethane foam (epoxy adhesive), and simulated and compared during the driving process the vibration characteristics (aerodynamics, mechanical motion, etc.) of an automobile engine hood with five different (2) The automotive body parts The automobile body, as the basic frame, is the main research subject for reducing the vehicle's weight.…”

Laser Welding of Metal-Polymer-Metal Sandwich Panels

“…Moreover, they also ensure the damping of vibrations, as well as with their low thermal conductivity due to the polymer material between the metal layers, thermal insulation effects. By combining these materials with reinforcing elements while designing different components, it is possible to compensate for the lack of rigidity and strength of the sandwich panels [6,7].…”