STANDARDIZED SUB-SCALE DYNAMOMETER SCALING METHOD FOR TRANSIT AND FREIGHT TRAIN APPLICATIONS

AN ABSTRACT OF THE THESIS OF John Goodloe, for the Master of Science degree in Mechanical Engineering, presented on April 13, 2016, at Southern Illinois University Carbondale. TITLE: STANDARDIZED SUB-SCALE DYNAMOMETER SCALING METHOD FOR TRANSIT AND FREIGHT TRAIN APPLICATIONS MAJOR PROFESSOR: Dr. Peter Filip Dynamometers are machines that are used in several industries for measuring force, torque, or power of a mechanism. These devices are in fact very useful in the friction material industry. Friction materials are created and then tested on dynamometers to analyze physical properties such as the dynamic coefficient of friction of the material based upon its retarding force against the wheel or disc, which is mounted to the dynamometer drive shaft. Dynamometer testing is expensive and often time consuming. Sub-scale dynamometers may be used to reduce cost, time, and material use while providing similar test results by implementing a proper scaling method. There are several scaling methods, but this approach will use surface analysis and the energy dispersed per surface contact area strategy to verify the testing conditions of both sub-scale and full scale testing. Since lab analysis costs are expensive, the project budget is restricted to analyzing the maximum of 1 full-scale disc and pad specimen and 2 subscale disc and pad sets. The test results are expected to prove that when the surface conditions of the analyzed specimens agree to each other, the dynamometer test results will also agree. Due to restrictions with budget and time the fastest and most effective way to test this hypothesis is by creating the baseline on the full-scale and then adjusting the scaling on the subscale dynamometer until similar results are given. Once similar dynamometer test results are obtained, the material specimens can be analyzed in the lab. Testing will continue as long as necessary, and if the expected results are not obtained, the results will still be tested for analysis and compared to the baseline. The results are expected to show that two separate machines may provide similar surface conditions for testing, as well as similar dynamometer test results for any given friction material. However, if the expected results cannot be obtained, then it may still prove that without matching the surface layer conditions while testing, the dynamometers recorded test results will not match either, which is in agreeance with the hypothesis