高强高温合金高速小切宽断续切削振动和加工不稳定性分析及切削参数优化

In the case of machining of many kinds of high temperature resistant aero-engine parts, there exists a phenomenon of high-speed, small cutting-width and interrupted cutting, which is common among high-speed cuttings of high-strength superalloy materials. Because it is very difficult for traditional theory of chatter and stability analysis to completely describe cutting vibration and machining instability of high-speed small cutting-width interrupted cutting of high-strength superalloy materials, the current project is to carry out research on unique dynamics of high-speed small cutting-width interrupted cutting of high-strength superalloy materials, in order to provide theoretical methods and practical tools for highly efficient and stable machining and optimization of machining parameters. Because tool wear is very serious during the process of machining high-strength superalloy materials, the current project is to establish an online optimization model of machining parameters with consideration of cutting tool state information in real time, in order to automatically adjust machining parameters and maintain optimal machining condition according to progressive tool wear. To address the shortcomings of sensor layout, information fusion theory and method existing in real-time monitoring of the cutting process, an investigation is conducted to study a high efficient, economical, enabling and steady sensor layout optimization strategy, establish a multi-level and multi-faceted sensor information fusion model, integrate information fusion to sensor layout optimization and identify the relationship between them through the effective use and reuse of information so as to improve the sensor layout optimization strategy, with consideration of constraints on the sensor layout.

在航空发动机多类重要耐高温零部件的切削加工场合，普遍存在高强高温合金高速小切宽断续切削现象。针对既有再生颤振理论难以全面概况高强高温合金高速小切宽断续切削振动和加工不稳定性，研究高强高温合金高速小切宽断续切削的独特动力学性态，为高强高温合金高速小切宽断续切削振动和加工不稳定性控制提供理论指导和实用工具。针对高强高温合金材料切削过程中刀具磨损严重，建立融合刀具实时状态信息的切削参数在线优化模型，根据切削过程刀具渐进磨损的变化进行切削参数的自动调整并保持最优切削状态。针对切削过程实时监测中传感器布置、信息融合理论和方法存在的局限性，综合考虑传感器布置受限条件，通过信息的有效利用及复用，研究在切削过程实时监测过程中高效、经济、适应性广和稳定性好的传感器优化布置策略，建立多层次、多方面的信息融合模型，并将传感器优化布置理论与信息融合技术相结合，研究两者之间作用关系，完善传感器优化布置策略。

数控铣削加工因其高效率高精度的特点，被广泛应用于航空、航天、国防、船舶等先进制造领域。当前，切削参数选择的不合理以及刀具路径的不光顺所引起颤振造成的加工质量恶化、刀具磨损加剧等仍然是亟待解决的重大难题。本项目为解决铣削加工中的效率和质量问题，深入了开展包括铣削加工切削稳定性分析、切削参数优化、光顺路径生成等方面的研究，具体研究内容如下：.（1）提出了高效高精求解铣削加工动力学时滞微分方程的时程精细积分法，对时滞微分方程中的状态项和时滞项分别使用三阶牛顿插值和埃尔米特插值多项式近似计算，同时将该方法拓展应用于变转速和变齿距铣削稳定性预测。.（2）建立了综合考虑铣削过程再生效应、过程阻尼和模态耦合效应的两自由度铣削动力学模型，提出了切削稳定域和表面位置误差的组合预测方法，以此为基础揭示过程阻尼与模态耦合对切削稳定性和表面位置误差的影响。.（3）基于扰动再生效应机理，构建了考虑螺旋角效应的变齿距与变转速铣削动力学模型，并结合时域仿真验证了该模型的有效性及分析方法的准确性；在此基础上通过数值仿真揭示刀具几何参数和主轴转速对切削稳定性的影响。.（4）提出了基于精细积分法的三维切削稳定性预测模型，构建以机床性能、表面粗糙度和切削稳定性等为约束条件，以加工时长和碳排放为目标函数的切削参数优化模型；提出了基于马尔可夫聚类的多目标优化决策方法以求解切削参数优化模型并辅助决策。.（5）提出了基于非稳态导热理论的数控铣削加工光顺刀具路径生成方法，分别针对封闭型腔、开放型腔以及含孤岛型腔的不同特征，采用不同的导热边界条件以及差分方程进行刀具路径的生成，并基于Hausdorff距离计算方法来保障加工的无残余。.（6）提出了基于Catmull-Rom样条的数控铣削加工解析式C3连续刀具路径光顺方法，通过插入可调Catmull-Rom样条对相邻离散线段的拐角进行光顺，并通过控制点和调节参数优化设计抑制光顺刀具路径与原始刀具路径之间的偏差。