• Proceedings of the KSME Conference
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• 2001.06b
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• pp.361-365
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• 2001

Laboratory tests are conducted to validate the mechanical model of a filament-wound composite shaft. Also, design charts are produced by validated analytical calculations based on the Timoshenko beam model of a layered steel/composite structure. The major results found are that steel/composite hybrid shafts can lead to better dynamic and static performances over steel or pure composite shafts of the same volume, and the most effective composite structures contain some steel in the form of a tubular core. These results can be used in the design process of composite boring bars and automotive drive shafts.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.4
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• pp.38-46
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• 1994

The vibration amplitude of boring bar is generally large at the tool tip, because it has the high length-diameter(L/D) ratio. A new dynamic cutting force model is presented by considering the change of shear angle under dynamic cutting. The boring bar is modelled as a cantilever with dynamic force acting at the tool end point. Based on this realistic continuous system model, the equation of motion of borring bar is solved by numerical computations. A good agreement is found between the proposed model and the experimental results.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.4
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• pp.694-704
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• 1988

A recursive parameter estimation scheme utilizing the variance perturbation method is applied to the workpiece deflection model during CNC turning process, in order to improve the cylindricity of slender workpiece. It features that it is based on exponentially weighted recursive least squares method with post-process measurement of finish surfaces at two locations and it does not require a priori knowledge on the time varying deflection model parameter. The measurements of finish surfaces by using two proximity sensors mounted face to face enable one to identify the straightness, guide-way, run-out eccentricity errors. Preliminary cutting tests show that the straightness error of the finish surface due to workpiece deflection during cutting is most dominant. Identifying the errors and recursive updating the parameter, the off-line control is carried out to compensate the workpiece deflection error, through single pass cutting. Experimental results show that the proposed method is superior to the conventional multi-pass cutting and the direct compensation control in cutting accuracy and efficiency.