| Summary: | In recent years the control of tool vibration has emerged as the critical area of scientific development. This is because tool vibration creates sound-noise and unwanted quality surface. Mathematically, the observed tool vibration is a ratio of the force acting on the tool to its dynamic stiffness. Because dynamic stiffness is strongly influence by tool damping, the tool vibration could be controlled by enhancing the damping ability of the tooling system. The Department of Production Engineering at KTH has designed new damped drilling tools which absorb the vibratory energy from machining. It is expected that they have better performances than the conventional drilling tools. In this paper, new drilling tools were tested and compared to conventional ones with Experimental Modal Analysis (EMA) and Machining tests. The natural frequencies, the damping ratios, and mode shapes were detected. Also the drilling tools were tested while mounted in the damped clamping device and the conditional clamping device. Taguchi method was then conducted to find the optimal cutting parameters of each combination of the drilling tool and the clamping device. The EMA shows that the damped tools have higher damping ratio than the conventional one. In the machining test, damped tools also achieve better quality surface while mounted in the conventional clamp. The damped clamp helps the conventional tool improve the damping ratio significantly; however it does not give any improvement for the damped tool.
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