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Bearings are a major component in any rotating system. With continually increasing speeds, bearing failure modes take new unconventional forms that often are not understood. In high speed applications, rolling element forces and gyroscopic moments can be significantly high compared to the applied forces acting on a bearing. Such moments create a “driving” torque causing outer race to creep. In this paper a mathematical model for the dynamics of a rolling element in a high speed bearing is derived. Preload values counterbalancing the torque driving the outer race to rotate can be predicted from this model. An attempt to experimentally measure this torque using a specially designed apparatus with integrated strain gauge torque sensor is also described. Both model and experimental measurements are aimed at understanding, and therefore preventing bearing failures due to outer race (creep) rotations.

Tapered roller bearings used to support pinion and differential gears in automotive drive axles perform best with accurate assembled preload. One of the most common high volume production assembly methods relies on bearing friction to adjust preload; however torque is an indirect measure of load, can be influenced by the raceway condition, and is difficult to control. A new method to measure preload utilizes frequency response to estimate axial preload from system stiffness. The stiffness can be measured dynamically and an assembly method automated to set preload without the need for torque or dimensional measurements. By eliminating the need for a torque signal, the raceway conditions which contribute to setting torque do not contribute to the preload setting accuracy. This study demonstrates the effectiveness of using frequency response to measure stiffness and estimate preload.

As the need for super high speed components (pumps, motors, etc) continue to grow rapidly, so does the need to make measurements at speeds higher than ever before. Bearings are a major component in any rotating system. With continually increasing speeds, bearing failure modes take new unconventional forms that often are not understood. Such measurements are impossible if bearings fail to perform. This paper will address the dynamic modes a bearing passes through and the potential failure modes associated with each. A review of the state of the art of current failure modes will be given, and then a hypothesis on some new failure modes associated with particular speeds will be discussion. The paper will also describe an apparatus that was designed especially to study these phenomena. Range of speed studied is 0- 60,000 rpm. Preliminary measurements indicated that this range breaks into three different zones: low (0-15,000 rpm), moderate (15,000-25,000 rpm) and high (25,000- 60,000 rpm).

This paper proposes and evaluates improvements to a crash simulation of a fuel delivery module in a fuel tank. The simulations were performed in ANSYS/LS-DYNA. Deviations between the original simulation and test data were studied and reasons for the deviations hypothesized. These reasons stemmed from some of the simplifying assumptions of the model. Improvements consisted of incorporating plasticity and strain rate effects into the material models. Performance criteria were also directly incorporated into the material models such that non-performing portions of the model could be deactivated during the simulation. Finally, solid-fluid interactions were added into the simulation to include the momentum transfer from fuel to the fuel delivery module. It was previously thought that effects of a crash would be most severe on the module when the fuel tank was empty and the module was full with fuel.

Chromium Molybdenum Steel (AISI 4130), commonly referred to as “Chrome Moly”, is one of the most popular materials used in the construction of tubular space frames and chassis components for racing applications. Its high strength, light weight and comparably low material cost make the reasons for its popularity quite obvious. However, there is one problem that is commonly overlooked: maintaining the strength component of Chrome Moly in areas exposed to high levels of heat followed by rapid cooling during welding. This paper seeks to better understand the affects of cooling due to welding on the strength of Chrome Moly tubing.

This paper details the use of experimental and test data based analytical techniques to resolve brake squeal. External excitation was applied to the brake system during operation on an inertia dynamometer and FRF measurements were taken. The operating conditions were varied with respect to disc velocity and brake line pressure. An experimental modal analysis under operating (EMA-OC) was performed on a disc brake, with a 2.6 kHz squeal, during squealing and non-squealing operational conditions. Two modes close in frequency to the 2.6 kHz squeal were identified from modal analysis of the brake system in a non-squealing operational condition which were not individually present during squealing conditions. These two modes were assumed to be the modes which couple due to friction and thus produce squeal in operation. A sensitivity analysis was then conducted on the modal model obtained from an EMA-OC non-squealing operational case.

A study has been conducted on a small engine cooling system in order to find a way to reduce common overheating problems at idle conditions and high engine speeds with restricted airflow. The system flow rates, pressure, and temperature characteristics were monitored at different positions in the system while engine speed was varied. The results show that by adjusting the flow rates according to certain variables, the overall effectiveness of the system is increased and overheating problems can be eliminated. The findings also show that this adjustment can be accomplished by incorporating a controllable electric water pump into the design. Dynamometer testing has also been conducted to show that, in addition to controlling flow rates, the use of the electric pump also possesses the potential of increasing the power output of the engine.

The airflow through a standard automotive throttle body is not exactly proportional to the displacement of the accelerator pedal. Therefore, another method is needed to open the butterfly valve in order to ensure that airflow through the throttle body is metered equal to pedal displacement. This paper finds that the implementation of a cam-type pulley is necessary to achieve this prescribed goal.

The design of a race engine intake system involves many design considerations. Two very important areas of design are the intake manifold's volume and geometry. In considering these variables there are several different possible intake configurations. Such configurations will include single and dual plenum designs, as well as volume transitions. Dynamometer testing objectives will test different intake designs for the best overall engine power by comparing the areas under the engine power curve. Of the four intakes tested, the 2003 intake was found to make the best overall power.

This paper reviews how sound transmission loss (STL) of insulators is affected by gravitational and thermal effects. A special STL test fixture was designed and fabricated to quickly and accurately obtain the STL measurement of a sample oriented at various controlled angles. The STL apparatus was designed to roll into a large reverberation chamber and act as the anechoic termination for a two-microphone approach to measuring STL. The fixture was also built with the intention of studying the temperature effects on a material's STL performance. A variety of samples, including lightweight and traditional barrier decoupled insulators, were tested in the horizontal, vertical, and inverted positions to evaluate gravitational/inertial effects. Thermal effects were investigated by bringing the STL apparatus and sample to a low temperature by moving outdoors, and then rolling the system into the reverberation chamber, at normal room temperature.