Abstract Some long strip-like thin-walled workpieces such as blades usually need to be manufactured by milling with two ends being clamped on the machine table. This paper presents a stability improvement method in this kind of thin-wall milling by applying tensile prestress to the workpiece. The methodology is described by developing theories to establish the relationship between the needed tensile prestress and the expected critical axial depth of cut. Influence of the workpiece natural frequency on the critical axial depth of cut is theoretically explained for the first time. It is found that increasing the workpiece natural frequency can locally improve the stability in milling, and based on this conclusion, quantitative equations relating the expected critical axial depth of cut to the workpiece natural frequency are theoretically derived and solved in detail. With the aid of modal analysis from finite element simulation, problem on how much tensile prestress should be used to increase the workpiece natural frequency to the expected level is explained. In short, the stability lobe of a thin-wall milling system is shifted to the expected stable zone by manipulating tensile prestress to the clamping areas of long strip-like part. Besides, a prototype device, which has the capacity of fixing and prestressing the workpiece, is originally invented to check the effectiveness of the proposed methodology. The proposed method together with the invented prestressing device is experimentally validated by carrying out a series of milling tests with and without prestress.

中文翻译：

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预应力提高薄壁铣削颤振稳定性的探讨

摘要 叶片等长条状薄壁工件通常需要通过铣削加工，两端夹紧在机床工作台上。本文提出了一种通过对工件施加拉伸预应力来提高这种薄壁铣削稳定性的方法。该方法是通过开发理论来描述的，以建立所需的拉伸预应力和预期的临界轴向切削深度之间的关系。首次从理论上解释了工件固有频率对临界轴向切深的影响。发现提高工件固有频率可以局部提高铣削的稳定性，并基于此结论，将预期的临界轴向切削深度与工件固有频率相关的定量方程从理论上推导出并详细求解。借助有限元模拟的模态分析，解释了应使用多少拉伸预应力才能将工件固有频率提高到预期水平的问题。简而言之，通过操纵长条状零件夹紧区域的拉伸预应力，将薄壁铣削系统的稳定瓣转移到预期的稳定区。此外，最初发明了一种具有固定和预应力工件能力的原型装置，以检查所提出方法的有效性。