| Summary: | 碩士 === 國立成功大學 === 機械工程學系碩博士班 === 97 === Workpieces after grinding process might bend or deflect due to thermal deformation and induced residual stress after grinding process, especially for slender workpiece with low thickness-to-length ratios. In this paper, the bending extent of thin workpieces is investigated as a parallelism property of thin plate as defined in the ASME Y14.5 Standard. A model for predicting the parallelism prediction of thin workpieces is developed based on the beam deformation theory by using and combined with a dimensionless factor, the thickness-to-length ratio, as a characteric parameter. This model considers Young’s modulus and moment of inertia of area, and assumes the central position of workpieces does not change as bending moments act on the both sides of workpiece. The relationship between thickness-to-length ratio and parallelism of thin workpieces has been analyzed and discussed. Under different cut depths and feed speeds, grinding experiments have been carried out on carbon steel with using an alumina grinding wheel. Experiment results indicate that the relationship between thickness-to-length ratio and parallelism of thin workpieces has an inverse-square relationship. As an application, the use of this model results in giving an indication of grinding conditions with reduced grinding passes from 30 to 14 and improved parallelism of thin workpieces by 76%.
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