| Summary: | 博士 === 國立中央大學 === 機械工程研究所 === 98 === The rapid development of the vehicle industry has made reducing product development time a major concern. The durability and riding comfort evaluation of ground vehicles were investigated by bench tests. This study seeks to identify a suitable accelerated approach to durability analysis for motorcycle components. This investigation involves field data acquisition, laboratory road load simulation, accelerated durability testing and fatigue life prediction. Two methods, “strain range editing technique” and “racetrack editing technique,” were applied to edit field strain histories for accelerated durability tests. Furthermore, four methods, including the “S-N approach with fatigue property of base metal,” “Eurocode 3 approach,” “BS 5400 approach,” and “BS 5400 approach with Gurney thickness modification,” were employed to assess fatigue life. Three road types and four damage levels were also used. The results demonstrated that the “BS 5400 approach with Gurney thickness modification” is a suitable method of assessing the durability of welded motorcycle components when the fatigue properties of critical points are not available. Both the “strain range editing technique” and “racetrack editing technique” can effectively edit strain histories with the expected quantity of fatigue damage, and demonstrate satisfactory agreement between the experimental data and predicted data.
In addition, the ride comfort qualities of three different sport-utility vehicles (SUVs) were determined using sensors, road data acquisition, and road load simulation in the laboratory via road and bench tests. Three road types, three driving speeds and one drive file were used. The point vibration total value and overall vibration total value (OVTV) based on the root mean square of the acceleration in the ISO 2631 standard and the seat effective amplitude transmissibility (SEAT) value were evaluated to compare the ride qualities of three SUVs. During a series of ride comfort tests, the comfort rankings of the target SUVs were equivalent between the road and bench tests. The ride qualities determined from the road and bench tests were strongly correlated; the linear correction factor was derived as OVTVcorrected bench = 0.9335×OVTVbench, and the correlation coefficient, R2, was 0.9908. Furthermore, the mean error of the OVTV for the road and bench tests ranged from 9.75% (original) to 0.2% (after correction). Finally, the procedures for ride comfort evaluation using a laboratory test system (four-poster) are described. These procedures allow for a fast and objective evaluation of ride comfort using bench tests with a correction factor.
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