共查询到19条相似文献,搜索用时 125 毫秒
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叶片的高速五轴铣削是高速切削技术的一个典型应用,切削参数的优化是关系到加工效率和加工经济性的重要环节。笔者通过借鉴两种铝合金材料的试验数据来优化高速铣削参数,以提高叶片的加工质量和效率。 相似文献
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铣削加工是一个复杂的能量消耗的过程,可以通过选取合理的铣削参数,降低铣削加工过程中设备的能量消耗。本研究将铣削加工过程的能耗简化为铣削加工功率和时间的线性关系,经过铣削试验,获得在不同铣削参数下的铣削设备功率消耗及铣削加工时间;应用正交试验设计的方法,将选取的铣削参数做进一步的优化,从试验中可以看出不同的铣削参数对铣削设备输出功率的影响;同时,对不同铣削参数下的加工时间进行了对比分析。试验表明,在选取的铣削参数中,每齿进给量对铣削设备加工时的输出功率和加工时间影响最大,其次是切削速度,影响最小的是背吃刀量。从而对铣削参数进行优化选取,在保证加工效率及质量的前提下,将铣削设备能耗降至最低。 相似文献
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为实现在加工过程中对薄壁件侧铣产生的较大切削变形进行在线控制,提出基于有限元数值模型和进给速度优化的在线控制策略。根据薄壁件切削过程的有限元仿真结果,建立数控机床进给速度、切削力、工件切削变形间的数值模型,进而确定用于控制变形的最优目标切削力。在具有开放式模块化的数控系统平台上开发了切削力信号实时采集、滤波功能和基于Brent-Dekker算法的进给速度在线优化策略,并根据滤波后的切削力及相应算法在加工过程中实时调整机床进给速度,保证切削力逐渐接近最优控制目标而实现切削变形的在线控制。试验结果表明,经过进给速度在线优化后的切削过程可将薄壁件侧铣变形控制在规定范围内,同时提高了切削效率。 相似文献
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以降低数控实践教学成本,提高加工效率为目标,构建了高速铣削加工参数多目标优化方案,合理设定了各类约束条件,并利用复合形法进行优化。具体分析了数控铣削加工切削要素及各类冷却加工形式,对切削速度、径向切削量、背吃刀量等较主要的切削用量的优化选择进行了探讨,为合理选择铣削加工工艺参数提供了参考依据。通过最高生产效率、最低生产成本、综合优化原则构建了最佳切削用量数学模型,为计算结果的准确性取得充实的保障。通过在实例教学中的应用,验证了优化方案的可行性,提高了加工效率,降低了实验材料成本。 相似文献
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As one of the bases of gradient-based optimization algorithms, sensitivity analysis is usually required to calculate the derivatives of the system response with respect to the machining parameters. The most widely used approaches for sensitivity analysis are based on time-consuming numerical methods, such as finite difference methods. This paper presents a semi-analytical method for calculation of the sensitivity of the stability boundary in milling. After transforming the delay-differential equation with time-periodic coefficients governing the dynamic milling process into the integral form, the Floquet transition matrix is constructed by using the numerical integration method. Then, the analytical expressions of derivatives of the Floquet transition matrix with respect to the machining parameters are obtained. Thereafter, the classical analytical expression of the sensitivity of matrix eigenvalues is employed to calculate the sensitivity of the stability lobe diagram. The two-degree-of-freedom milling example illustrates the accuracy and efficiency of the proposed method. Compared with the existing methods, the unique merit of the proposed method is that it can be used for analytically computing the sensitivity of the stability boundary in milling, without employing any finite difference methods. Therefore, the high accuracy and high efficiency are both achieved. The proposed method can serve as an effective tool for machining parameter optimization and uncertainty analysis in high-speed milling. 相似文献
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Micro and nano-particles have been successfully and widely applied in many industrial applications. The mechanical milling process is a popular technique used to produce micro and nano-particles. Therefore, it is very important to improve milling process efficiency and quality by determining the optimal milling parameters. In this study, the effects of the main mechanical milling parameters: milling time, process control agent (PCA), ball to powder ratio (BPR) and milling speed in the planetary ball milling of nanocrystalline Al 2024 powder were optimized by the Taguchi method. Mean particle size (d50) was used to evaluate the effect of process parameters on the mechanical milling process. The orthogonal array experiment is conducted to economically obtain the response measurements. Analysis of variance (ANOVA) and main effect plot are used to determine the significant parameters and set the optimal level for each parameter. The as-received and milled powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and a laser particle size analyzer, respectively. The results indicate that the process control agent significantly affects (84% contribution) the mean particle size (d50) while other parameters have a lower effect (16% contribution). The developed model can be used in the mechanical milling processes in order to determine the optimum milling parameters for minimum particle size. 相似文献
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Xing Zhang Jun Zhang Bo Pang DiaoDiao Wu XiaoWei Zheng WanHua Zhao 《The International Journal of Advanced Manufacturing Technology》2016,87(9-12):3373-3388
An efficient approach for milling stability and surface location error (SLE) prediction with varying time delay and cutter runout effect is presented in this paper. Firstly, based on the tooth trochoid motion, the paper proposes a varying time delay model during cutter/workpiece engagement with taking cutter runout into account, establishes a milling dynamic model under arbitrary feed direction, and then derives the state transition matrix in one cutter rotation period by using the Cotes numerical integration formula. The milling stability of the dynamics system are obtained by using Floquet theory. According to the fixed point theory, the displacement response of the dynamic system and the method for solving the SLE are both developed. Later, a series of numerical and experimental works are conducted. The numerical verification shows that the proposed method can achieve a faster convergence rate and higher calculation efficiency than other previous methods. Meanwhile, the prediction of stability and SLE are in good agreement with the experimental results, and have a high accuracy for stability prediction when cutter runout and varying time delay considered. In the end, the numerical studies show that the milling stability and SLE strongly depends on the actual milling conditions, including milling parameters, cutter runout, cutter geometric parameters, and asymmetric structural dynamic parameters, which are helpful for milling process optimization. 相似文献
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应力分布均匀程度是衡量精密机电产品装配精度和性能稳定性的重要指标,均匀的应力分布也是当前精密机电产品装配过程所追求的目标之一。形状设计是改善装配界面接触应力分布的重要途径,针对当前基于应力分布的装配界面形状主动设计方法中初始参数取值难以确定,且相关参数对优化过程计算效率、数值计算稳定性影响较大的问题,提出了一种根据优化过程中接触应力分布均匀程度变化信息来调节优化参数的自适应参数计算方法。并以典型单螺栓连接结构为设计对象,对比了采用自适应参数设计方法与采用固定参数设计方法分别进行装配界面形状主动设计后的结果。理论分析结果表明:该方法可以很好地解决基于应力分布的装配界面形状主动设计方法中初始参数难以确定的问题,同时提高了优化效果、计算效率和优化过程中的数值计算稳定性。 相似文献