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The Michelin Tweel tire structure has recently been developed as an innovative non-pneumatic tire which has potential for improved handling, grip, comfort, low energy loss when impacting obstacles and reduced rolling resistance when compared to a traditional pneumatic tire. One of the potential sources of vibration during rolling of a non-pneumatic tire is the buckling phenomenon and snapping back of the spokes in tension when they enter and exit the contact zone. Another source of noise was hypothesized due to a flower petal ring vibration effect due to discrete spoke interaction with the ring and contact with the ground during rolling as the spokes cycle between tension and compression. Transmission of vibration between the ground force, ring and spokes to the hub was also considered to be a significant contributor to vibration and noise characteristics of the Tweel.

This paper discusses a compliant link suspension concept developed for use on a high performance automobile. This suspension uses compliant or flexible members to integrate energy storage and kinematic guidance functions. The goal of the design was to achieve similar elasto-kinematic performance compared to a benchmark OEM suspension, while employing fewer components and having reduced mass and complexity, and potentially providing packaging advantages. The proposed suspension system replaces a control arm in the existing suspension with a ternary supported compliant link that stores energy in bending during suspension vertical motion. The design was refined iteratively by using a computational model to simulate the elasto-kinematic performance as the dimensions and attachment point locations of the compliant link were varied, until the predicted performance closely matched the performance of the benchmark suspension.

For incorporating titanium components onto a vehicle in place of existing iron/steel components, there is a need for a methodical procedure to ensure successful and efficient integration. This involves a refinement over standard lightweight engineering procedures. In this paper, a suitable procedure is developed for replacing a structural component with titanium and the method realized. Design and manufacturing issues associated with integrating titanium are identified and addressed. The importance of justifying component replacement in terms of life-cycle costs rather than purely by the manufacturing cost alone is also emphasized.

Surface defects were demonstrated to result from high productivity machining (HPM) as well as conventional machining of a titanium alloy Ti-6Al-4V, with HPM causing the larger sized defects. These defects could act as initiation sites for fatigue cracks showing that machining would affect fatigue strength and life of the part produced. A finishing pass appears to remove the defects. Better understanding is needed of the relationships between machining, surfaces, and strength.

High speed machining of aluminum and magnesium helicopter gearcases was experimentally demonstrated to be five times more productive than contemporary conventional commercial practice for suitable operations. Appropriate techniques and performance characteristics are discussed for face milling, endmilling and planetary milling operations. Potential problem areas, such as surface characteristics and machine tool performance requirements are discussed.

A stiffness requirement for high speed milling machines is determined by examining the stiffness of current generation high speed spindles. The desire for stability against chatter dictates that the stiffness of the machine structure and drives, when reflected to the tool tip exceed the spindle/tool holder/tool stiffness. The stiffness characteristics of a classical serial machine tool designed expressly for high speed milling are shown. Another potential design for high speed machining applications, the parallel kinematic or hexapod structure is also examined. It is found that hexapod structures exhibit lower structural stiffness than can be achieved in serial machines when using the same drive components. Furthermore, the stiffness of the hexapod structure varies widely across the workspace, leading to difficulties in control and limiting the achievable accuracy.

Clemson University has recently partnered with the State of South Carolina, BMW, Michelin, Timken, and other partner companies to create new MS and PhD programs in Automotive Engineering. These academic programs are housed in a new 90,000 square foot facility located at the newly created Clemson University International Center for Automotive Research (CU-ICAR) in Greenville, SC. This paper describes a unique course, Automotive Development Processes, developed as a part of the Automotive Engineering curriculum by the authors, Dr. Julian Weber, Manager in BMW Electric/Electronics and Driver Environment development in Munich, Germany, and Dr. John Ziegert, a member of the Automotive Engineering Faculty at Clemson University. Due to geographic and time constraints for Dr. Weber, the course is offered as a 2 week intensive course during the university’s Maymester term.

This paper describes a computational approach to investigating spoke vibrations in cast polyurethane spoked wheels during high-speed rolling. It focuses on four aspects: 1) Creating a two-dimensional finite element model of a cast polyurethane rolling wheel which is in contact with a rigid plane to observe the spoke vibrations. 2) Investigating the effect of rolling speed on the observed spoke vibrations. 3) Investigating the effect of spoke thickness on spoke vibration frequencies. 4) Creating a three-dimensional spoke model to investigate spoke vibrations which exhibit both symmetric and anti-symmetric out-of-plane modes.