Abstract
Light weight composites possess high specific strength and modulus and have been widely used in various applications such as transportation, marine, and aerospace. Replacing metallic components with reinforced composites in mass transit helps to lower weight and therefore increase fuel efficiency and decrease maintenance cost without compromising performance. In this work, an air conditioning cover roof door on a mass transit bus was designed, analyzed, and manufactured for a replacement of an aluminum component. Novel design using thermoplastic composites materials and thermo-forming processing technology were demonstrated to form the part. Innovative composite materials namely thermoplastic poly olefin as the outer skin and a ribbed lofted glass mat thermoplastic inner liner to provide structural stiffness and strength were used. Weight savings of 39% and reduction of freestanding deflection of 42% were realized using the composite approach compared to the metallic counterpart. Materials technologies to enable production of safe and cost-effective lightweight vehicles have been identified as critical to reducing fuel consumption in automobiles, light trucks, and mass transit vehicles. 75% of fuel consumption relates directly to vehicle weight. Reducing weight can improve the price-to-performance ratio of transportation systems. Novel innovative lightweight materials provide avenues to produce increased fuel efficiency and reduced emission of harmful pollutants, without compromising on performance and size. A 20% weight reduction could yield 12% -> 14% fuel economy improvement.
In this work, a lightweight thermoplastic composite mass transit bus roof door was designed, manufactured, and prototyped. Quick fabrication of a prototype part from a 3-D CAD models is call rapid prototyping .The material systems which were used were thermoplastic poly olefin in conjunction with lofted glass mat thermoplastic sheets.
The design was intended to be a form-fit-functional replacement of an existing aluminum mass transit bus roof door.
Keywords: Thermoplastic composites; Bus roof door; Thermoforming, Stereolithography