On the surface of 128° yx-LiNbO3 substrate, two pairs of Inter-Digital Transducers (IDTs) are parallelly arranged in the propagation direction, which is a stator of surface acoustic wave (SAW) rotary motors. A pl...On the surface of 128° yx-LiNbO3 substrate, two pairs of Inter-Digital Transducers (IDTs) are parallelly arranged in the propagation direction, which is a stator of surface acoustic wave (SAW) rotary motors. A plastic disk with small balls distributed around the circumference is a rotor. When a high frequency voltage is inputted to two IDTs, two Rayleigh wave beams are generated and are propagating on the substrate in opposite directions with each other. The resulting local relative motion between the particles of the stator and the balls produces two inverse frictional forces to form a moment to drive the rotor. The experimental results and theoretical analysis and calculation for two operating frequencies are accomplished and discussed.展开更多
There are many advanced tooling approaches in metal cutting to enhance the cutting tool performance for machining hard-to-cut materials. The self propelled rotary tool （SPRT） is one of the novel approaches to improv...There are many advanced tooling approaches in metal cutting to enhance the cutting tool performance for machining hard-to-cut materials. The self propelled rotary tool （SPRT） is one of the novel approaches to improve the cutting tool performance by providing cutting edge in the form of a disk, which rotates about its principal axis and provides a rest period for the cutting edge to cool and allow engaging a fresh cutting edge with the work piece. This paper aimed to present the cutting performance of SPRT while turning hardened EN24 steel and optimize the machining conditions. Surface roughness （Ra） and metal removal rate （rMMR） are considered as machining perfor- mance parameters to evaluate, while the horizontal incli- nation angle of the SPRT, depth of cut, feed rate and spindle speed are considered as process variables. Initially, design of experiments （DOEs） is employed to minimize the number of experiments. For each set of chosen process variables, the machining experiments are conducted on computer numerical control （CNC） lathe to measure the machining responses. Then, the response surface method- ology （RSM） is used to establish quantitative relationships for the output responses in terms of the input variables. Analysis of variance （ANOVA） is used to check the adequacy of the model. The influence of input variables on the output responses is also determined. Consequently, these models are formulated as a multi-response optimi- zation problem to minimize the Ra and maximize the rMMR simultaneously. Non-dominated sorting genetic algorithm-II （NSGA-II） is used to derive the set of Pareto-optimal solutions. The optimal results obtained through the pro- posed methodology are also compared with the results of validation experimental runs and good correlation is found between them.展开更多
基金This work was supported by the National Natural Science Foundation of China
文摘On the surface of 128° yx-LiNbO3 substrate, two pairs of Inter-Digital Transducers (IDTs) are parallelly arranged in the propagation direction, which is a stator of surface acoustic wave (SAW) rotary motors. A plastic disk with small balls distributed around the circumference is a rotor. When a high frequency voltage is inputted to two IDTs, two Rayleigh wave beams are generated and are propagating on the substrate in opposite directions with each other. The resulting local relative motion between the particles of the stator and the balls produces two inverse frictional forces to form a moment to drive the rotor. The experimental results and theoretical analysis and calculation for two operating frequencies are accomplished and discussed.
文摘There are many advanced tooling approaches in metal cutting to enhance the cutting tool performance for machining hard-to-cut materials. The self propelled rotary tool （SPRT） is one of the novel approaches to improve the cutting tool performance by providing cutting edge in the form of a disk, which rotates about its principal axis and provides a rest period for the cutting edge to cool and allow engaging a fresh cutting edge with the work piece. This paper aimed to present the cutting performance of SPRT while turning hardened EN24 steel and optimize the machining conditions. Surface roughness （Ra） and metal removal rate （rMMR） are considered as machining perfor- mance parameters to evaluate, while the horizontal incli- nation angle of the SPRT, depth of cut, feed rate and spindle speed are considered as process variables. Initially, design of experiments （DOEs） is employed to minimize the number of experiments. For each set of chosen process variables, the machining experiments are conducted on computer numerical control （CNC） lathe to measure the machining responses. Then, the response surface method- ology （RSM） is used to establish quantitative relationships for the output responses in terms of the input variables. Analysis of variance （ANOVA） is used to check the adequacy of the model. The influence of input variables on the output responses is also determined. Consequently, these models are formulated as a multi-response optimi- zation problem to minimize the Ra and maximize the rMMR simultaneously. Non-dominated sorting genetic algorithm-II （NSGA-II） is used to derive the set of Pareto-optimal solutions. The optimal results obtained through the pro- posed methodology are also compared with the results of validation experimental runs and good correlation is found between them.
