共查询到20条相似文献,搜索用时 15 毫秒
1.
A differential geometry approach to analysis of thermal forming 总被引:2,自引:0,他引:2
E.W. Reutzel L. Zhang P. Michaleris 《International Journal of Mechanical Sciences》2006,48(10):1046-1062
2.
以传统的端铣切削力模型为基础,提出了一种新的端铣加工中静态切削力的预报模型。该模型考虑了复杂的工件形状和不同的铣刀进给轨迹。给出了一种新的工件和铣刀接触算法。 相似文献
3.
Ik Soo Kang Jeong Suk Kim Yong Wie Seo 《Journal of Mechanical Science and Technology》2008,22(2):293-299
The analysis of the cutting force in micro end milling plays an important role in characterizing the cutting process, as the
tool wear and surface texture depend on the cutting forces. Because the depth of cut is larger than the tool edge radius in
conventional cutting, the effect of the tool edge radius can be ignored. However, in micro cutting, this radius has an influence
on the cutting mechanism. In this study, an analytical cutting force model for micro end milling is proposed for predicting
the cutting forces. The cutting force model, which considers the edge radius of the micro end mill, is simulated. The validity
is investigated through the newly developed tool dynamometer for the micro end milling process. The predicted cutting forces
were consistent with the experimental results. 相似文献
4.
D. Roth F. Ismail S. Bedi 《The International Journal of Advanced Manufacturing Technology》2005,25(1-2):140-144
Mechanistic models of the milling process must calculate the chip geometry and the cutter edge contact length in order to predict milling forces accurately. This task becomes increasingly difficult for the machining of three dimensional parts using complex tool geometry, such as bull nose cutters. In this paper, a mechanistic model of the milling process based on an adaptive and local depth buffer of the computer graphics card is compared to a traditional simulation method. Results are compared using a 3-axis wedge shaped cut – a tool path with a known chip geometry – in order to accommodate the traditional method. Effects of cutter nose radius on the cutting and edge forces are considered. It is verified that there is little difference (1.4% at most) in the predicted force values of the two methods, thereby validating the adaptive depth buffer approach. The numerical simulations are also verified using experimental cutting tests of aluminium, and found to agree closely (within 12%). 相似文献
5.
6.
基于偏最小二乘回归(PLSR)方法的铣削力模型系数辨识研究 总被引:8,自引:0,他引:8
在已有的铣削力模型基础上,建立一种适应多种工况条件下的铣削力系数多项式模型,提出一种方便、有效的多项式模型系数的辨识方法。即通过混合位级正交设计方法设计实验,获得实验数据;利用偏最小二乘回归分析方法——PLSR在模型参数辨识中的优势。仿真和实验结果表明,该方法不但可以准确、可靠地建立适用于不同工况条件的铣削力系数模型,同时,具有实验次数少,建模计算量小、辨识速度快,模型预测能力强等特点,模型参数具有较为明显的物理意义。文中最后给出了铣削加工LY12和45#钢的两种不同材料的仿真实例。 相似文献
7.
8.
高速车削镍基高温合金GH4169的切削力仿真研究 总被引:1,自引:0,他引:1
基于Deform 3D仿真软件建立了GH4169高温合金高速车削的有限元模型,采用四因素三水平正交试验方法研究了切削用量和刀具几何参数对切削力的影响规律,并建立了切削力经验公式。研究结果表明:在高速车削GH4169的过程中,对切削力影响最大的参数是切削深度,其次是进给量和前角,最后是刀尖圆弧半径;切削力随切削深度和进给量的增大而增大,随前角的增大呈现先降低又升高的趋势,而刀尖圆弧半径增大时切削力变化不大;最佳参数组合为:进给量0.2mm/r,切削深度0.4mm,前角10°,刀尖圆弧半径0.2mm。 相似文献
9.
对于切削力的建模通常采取将切削刃边界离散化的方法,然而在车削的最后阶段,由于刀具的刀尖半径圆弧较小,在正交切削试验中辨识局部切削力模型具有很大的局限性。本文采用一种新颖的试验配置来研究圆弧半径rE对切削力的影响。在切削试验中考虑了刀具半径,在圆柱外圆切削试验和端面切削试验的基础上,将试验结果与反向辨识相比较,该方法能够证实圆弧半径rE对切削力有很大的影响。 相似文献
10.
11.
12.
采用响应曲面法中的Box-Behnken 实验设计方法(BBD),设计出四因素三水平的Fe基非晶合金涂层切削力实验方案,研究切削参数(切削速度、进给量和切削深度)和刀具结构参数的变化对Fe基非晶合金涂层切削力的影响规律和影响因素,运用方差分析法获取了影响切削力分量的显著性水平,得到低切削速度下Fe基非晶合金涂层的最佳切削工艺参数。通过对实验数据的多元二次拟合,建立了Fe基非晶合金切削力最小二乘回归预测模型,并通过实例验证了Fe基非晶合金涂层切削力预测模型的可行性和实用性。 相似文献
13.
This study investigates the vibration problems of an axially loaded non-uniform spinning twisted Timoshenko beam. First, using the Timoshenko beam theory and Hamilton's principle, we derive the governing equations and boundary conditions of the beam. Secondly, the differential transform method is used to solve these equations with appropriate boundary conditions. Finally, the effects of the twist angle, spinning speed, and axial force on the natural frequencies of a non-uniform Timoshenko beam are investigated and discussed. 相似文献
14.
车削切削力不确定性的模糊—灰色预测 总被引:2,自引:0,他引:2
为了定量预测车削力的不确定性范围 ,基于对称模糊数、线性规划理论和灰色理论 ,提出了一种切削力不确定性的模糊—灰色预测方法 ,建立了用于获取评价数据的车削力测量系统以验证该方法的有效性。预测与实测结果的对比分析表明 :对于给定的切削条件 ,预测值是可变力的一个范围 ,而不是用传统方法所得的一个确定点 ,实测力以较小的相对误差落在预测范围内 相似文献
15.
F. Čuš 《The International Journal of Advanced Manufacturing Technology》2000,16(6):392-403
The paper deals with the optimisation model of cutting variables by which the manufacturing costs should be reduced to the
lowest possible value. The optimisation strategy takes place in two steps by taking into account all input variables (technological
limitations). First, the tool geometric variables are changed using selected cutting variables; in this way, the smallest
cutting force variables are determined. Geometric variables for the case of the smallest cutting force are used for the second
optimisation step in which the cutting variables are changed. Optimisation of the cutting variables is tested practically
under workshop conditions. In this way, important information about the validity of the optimised values is obtained. If there
are significant differences between the theoretical and practical values, then the theoretical values must be corrected (correction
of cutting variables). As the study of the cutting processes requires much experimental and theoretical work and applies to
a very large body of data, we have organised an information centre for cutting conditions. When forming the information centre
for cutting conditions, it was impossible to avoid the requirement that the technological database must be actively included
in the computer-supported integrated manufacture. 相似文献
16.
17.
This paper focuses on an application of an electro-hydraulic force tracking controller combined with an offline designed feedback controller (ODFC) and an online adaptive compensator in order to improve force tracking performance of an electro-hydraulic force servo system (EHFS). A proportional-integral controller has been employed and a parameter-based force closed-loop transfer function of the EHFS is identified by a continuous system identification algorithm. By taking the identified system model as a nominal plant model, an H∞ offline design method is employed to establish an optimized feedback controller with consideration of the performance, control efforts, and robustness of the EHFS. In order to overcome the disadvantage of the offline designed controller and cope with the varying dynamics of the EHFS, an online adaptive compensator with a normalized least-mean-square algorithm is cascaded to the force closed-loop system of the EHFS compensated by the ODFC. Some comparative experiments are carried out on a real-time EHFS using an xPC rapid prototype technology, and the proposed controller yields a better force tracking performance improvement. 相似文献
18.
19.
采用金属成形有限元分析软件Deform3D建立了可转位硬质合金车刀车削45钢的三维斜角切削有限元模型,利用该模型进行了切削加工模拟,得到切削力的数值并给出了切削力随时间的变化曲线.通过设置不同的切削参数,对不同参数下的车削力进行比较,分析各个切削参数对车削力的影响规律,为研究刀具的切削性能提供有用的数据. 相似文献