3D printing for customised design : unmanned vehicles-drive-line parts
Ng, Marjorie Shu Fen
Date of Issue2017-05-23
School of Mechanical and Aerospace Engineering
Additive Manufacturing (AM) is the process of adding materials atop one another until a three-dimensional (3D) product is formed. A 3D model in a computer-aided-design (CAD) program will be sliced into layers to be built upon. In the automotive industry, AM has only been used to create prototypes and small components. AM can offer advantages like the freedom to design any geometry, which leads to light-weight products. It allows several parts to be printed as one, eliminating the need for assembly, thus reducing logistics and cost. It also reduces material wastes by printing exactly what is needed. Unlike conventional methods (which requires molds and tools), manufacturing of products in AM can be changed simply by modifying the CAD file, making customization convenient. With lighter and customizable automobiles, more customers will be attracted. A lighter vehicle also leads to a fuel efficient car that is environmentally sustainable. However, the speed of AM is hindering its growth in the automotive industry. Material compatibility, cost, and the fact that current AM machines can only manufacture small products also hamper its prospects. Furthermore, with the growth of Industry 4.0, it is more essential for AM to rise up. In Industry 4.0, machines stay connected to help improve efficiencies of systems and processes. AM can manufacture and embed sensors and antennas in products, making them connected to the network instantaneously. Electronic circuitries are produced using Aerosol Jet Technology. It sprays very fine conductive particles onto any surfaces, and is contactless and maskless. Other AM systems include selective laser sintering (SLS), selective laser melting (SLM), electron beam melting (EBM) and Polyjet. ii SLM uses a laser beam to melt the powder particles together to form a solid. SLS uses a laser beam to sinter powder particles together, thus it is porous and not as strong as the former system. EBM is similar to SLM, but it uses an electron beam instead. Polyjet deposits a curable material and the UV light on the print head immediate cures it. Metals and polymers are used throughout AM. During the design stage of any product, the AM method and material to be used must be taken into consideration to allow a seamless and efficient process. A bumper of a radio controlled rally car was redesigned to attain a good strength to weight ratio. It was decided that Polyjet would be used as it produces precise and accurate features, but does not compromise on strength. The materials used were VeroMagenta and VeroWhite because they have high tensile strength, flexural strength, and flexural modulus, qualities for a good bumper. Calculations were done to determine the largest force the rally car will experience. The initial bumper was modelled in a CAD program before the design process started. Finite element analysis was carried out after each design was generated to examine the Von Mises stress distribution and determine if the design was safe under the most extreme impact. Finally, the most optimized design was chosen and printed to be fitted onto the rally car.
Final Year Project (FYP)
Nanyang Technological University