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1.
球头铣刀铣削过程的物理建模与仿真 总被引：1，自引：0，他引：1
给出了球头铣刀刃线几何模型,采用理论切削力分析与实验-系数识别相结合的方法,建立了新的螺旋刃球头铣刀的铣削力模型;建立了考虑刀杆柔性的球头铣刀铣削振动模型;考虑刀具动态变形和工件表面波纹对切削厚度的再生反馈,建立了球头刀铣削动力学模型,对动态铣削过程进行了仿真,证明离线仿真可以对铣削过程动特性做出准确的预测. 相似文献
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In this paper, a series of experiments were performed by high speed milling of Ti-6.5Al-2Zr-1Mo-1V (TA15) by use of polycrystalline diamond (PCD) tools. The characteristics of high speed machining (HSM) dynamic milling forces were investigated. The effects of the parameters of the process, i.e., cutting speed, feed per tooth, and depth of axial cut, on cutting forces were studied. The cutting force signals under different cutting speed conditions and different cutting tool wear stages were analyzed by frequency spectrum analysis. The trend and frequency domain aspects of the dynamic forces were evaluated and discussed. The results indicate that a characteristic frequency in cutting force power spectrum does in fact exist. The amplitudes increase with the increase of cutting speed and tool wear level, which could be applied to the monitoring of the cutting process. 相似文献
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To predict the distortion of aerospace monolithic components, a model is established to simulate the numerical control （NC） milling process using 3D finite element method （FEM）. In this model, the cutting layer is simplified firstly. Then, the models of cutting force and cutting temperature are established to gain the cutting loads, which are applied to the mesh model of the part. Finally, a prototype of machining simulation environment is developed to simulate the milling process of a spar. Key factors influencing the distortion, such as initial residual stress, cutting loads, fixture layout, cutting sequence, and tool path are considered all together. The total distortion of the spar is predicted and an experiment is conducted to validate the numerical results. It is found that the maximum discrepancy between the simulation results and experiment values is 19.0%. 相似文献
4.
根据成形法铣削螺旋锥齿轮切齿原理,推导出螺旋锥齿轮齿槽曲面的一元四次方程,通过求解一元四次方程得到齿槽上的关键点,为在Delphi＋ OpenGL环境下,利用所求得的关键点完成齿坯模型的建立以及仿真铣削过程的建立提供数据点.本文对比了在Delphi和Matlab下求解一元四次方程的不同,验证了本文算法的正确性. 相似文献
5.
研究了球头铣刀高速铣削过程铣削力建模与仿真。考虑了作用在前、后刀面上的正压力和摩擦力,建立了高速铣削加工中局部铣削力模型,在上述基础上建立了整体铣削力的模型。通过铣削实验,验证了所建模型的正确性。 相似文献
6.
To improve the processing efficiency and the quality of orbital milling hole of aerospace Al-alloy, the big-pitch influence on cutting force and hole quality was studied experimentally. First, a program based on horizontal lathe was proposed based on kinematics analysis of orbital milling. Then, the cutting force at different stages and the hole quality with different pitches were measured. Results show that the axial force and radial force increase with the pitch amplification during orbital milling. However, the axial force in the orbital milling hole is about 8—10 times smaller than that in the conventional drilling. The diameter error of milling hole is 48—93 μm, and the surface roughness of milling hole is 1.2—1.7 μm. Finally, an orbital milling device with big pitch was designed. 相似文献
7.
This paper studies the micro-cutting characteristics of aluminum alloy (2A12) based on a series of orthogonal experiments and finite element method (FEM) simulations. An energy-based ductile failure law was proposed in the FEM simulation. The simulated cutting forces and chip morphology were compared with experimental results. The simulation result indicates that there is a close relationship between the cutting force and cutting heat. The micro-cutting force decreases as the heat flux vector increases. Both the cutting heat and the micro-cutting force need a finite time to achieve a steady state. It is observed that with the cutting speed of 169.95 m/min and uncut chip thickness of 6 μm, the heat flux vector in the workpiece increases to a stable value after 0.06 ms; meanwhile, the principal cutting force decreases to a steady state correspondingly, i.e., the micro-cutting process achieves the steady state. It is concluded that the steady state micro-cutting simulation can reflect the cutting process accurately. 相似文献
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In order to improve the present aviation ejection escape system, the application of explosion cutting technique to aviation escape system is proposed to weaken the strength of canopy before ejecting it. A series of mini cutting explosives are designed to investigate the process of splitting PMMA plate. The phenomenon of spallation in PMMA is observed. The effects of different parameters of mini cutting explosives on the cutting depth are obtained. Consequently the appropriate material of half-circular metal covers, explosive types and the ranges of charge quantities are determined. On the other hand, the cutting process of aviation PMMA plate by mini cutting explosives is simulated by means of nonlinear dynamic analysis code LS-DYNA. In finite element analysis,Arbitrary Lagrangian Euler (ALE) algorithm is used to depict the fluid property of high energy explosives. Continuous damage material model is used to simulate the complicate dynamic damage behavior of PMMA due to explosion shock waves. Only sliding contact option is defined to fulfill the fluid-structure interaction between explosives and PMMA plate by distributed parameter methods. Phenomenon of spallation observed in the experiment is presented in the simulation. The relationship between the penetration depth of PMMA plate and charge linear density obtained by numerical simulation agrees well with experimental result. 相似文献
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通过应用VB语言编制程序,以计算绘图所需的齿轮范成参数实现刀具和齿坯的范成运动和刀具的切削运动,实现任意模数、任意齿数不同压力角及不同变位系数齿轮的动态切削仿真,克服了采用齿廓范成仪做实验时,参数不能改变的局限性,基本满足现代化教学要求. 相似文献
12.
针对难加工球墨铸铁材料进行高速铣削工艺参数优化研究,设计了四因素四水平正交实验,以获得铣削用量对加工过程力和表面粗糙度的影响关系,并利用多元回归分析建立铣削分力和粗糙度的经验模型。研究结果表明:每齿进给量对粗糙度值影响最为显著,铣削参数设置不同,产生的铣削分力不同,背吃刀量对铣削分力影响最大。针对最小铣削力与最小粗糙度的目标,分别得出最优的铣削用量参数。 相似文献
13.
The objective of the present research is to investigate the relationship among tool wear, surface topography, and surface roughness when high-speed end milling Ti-6Al-4V alloy, and also to define an optimal flank wear criterion for the cutting tool to integrate tool life and the surface roughness requirements of the finish milling process. An annealed Ti-6Al-4V alloy was selected as the workpiece material, undergoing end milling with uncoated carbide inserts. The flank wear of the insert was observed and measured with the toolmaker＇s microscope. To examine machined surfaces, 3D surface topography was provided by the white light interferometer, and the arithmetical mean roughness （Ra） was calculated with the WYKO Vision32 software. The flank wear increases with cutting time, and the maximal flank wear is set as the flank wear criterion. As the cutting process progresses, tool wear is the predominant factor affecting the variation of surface roughness. According to the plots for the tool wear propagation and surface roughness variation, an optimal flank wear criterion can be defined which integrates the tool life and the surface roughness requirements for the finish milling process. 相似文献
14.
The hole-making process in stack materials consisting of carbon fiber reinforced plastics(CFRP) and Ti-6Al-4V remains a critical challenge. In this paper, an experimental study on the helical milling of CFRP/Ti-6Al-4V stacks was conducted by using two different machining strategies. Helical milling strategyⅠ machines both materials with identical machining parameters, while machining strategyⅡ uses two sets of machining parameters to machine each material. Helical milling performance was evaluated by the following indicators: tool life, cutting forces, hole quality(including diameter deviation, roundness, roughness, and hole edge quality). The results demonstrate that helical milling strategy Ⅱ outperformed strategy Ⅰ, leading to longer tool life(up to 48 holes), smaller cutting forces and better hole quality with higher geometric accuracy and smoother surface finish(Ra≤ 0.58 μm for Ti-6Al-4V and Ra ≤ 0.81 μm for CFRP), eliminating the need for reaming or de-burring. 相似文献
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To investigate cutting performance in the helical milling of carbon fiber reinforced polymer (CFRP), experiments were conducted with unidirectional laminates. The results show that the influence of cutting parameters is very significant in the helical milling process. The axial force increases with the increase of cutting speed, which is below 95 m/min; otherwise, the axial force decreases with the increase of cutting speed. The resultant force always increases when cutting speed increases; with the increase of tangential and axial feed rates, cutting forces increase gradually. In addition, damage rings can appear in certain regions of the entry edges; therefore, the relationship between machining performance (cutting forces and hole-making quality) and cutting parameters is established using the nonlinear fitting methodology. Thus, three cutting parameters in the helical milling of CFRP, under the steady state, are optimized based on the multi-objective genetic algorithm, including material removal rate and machining performance. Finally, experiments were carried out to prove the validity of optimized cutting parameters. 相似文献
16.
对数控编程计算机碰撞仿真加工进行分析和研究:通过在UG NX中进行二次开发,探讨了在UG NX中开发数控机床切削仿真加工环境的方法,并以DMU 70cV万能数控铣五轴联动加工中心为例,详细介绍了在UG NX中对特殊结构的数控机床的切削仿真加工环境进行开发的方法,开发了DMU 70eV在UG NX中的碰撞仿真加工环境。 相似文献
17.
针对对称铣削系统在加工过程中会出现协同位姿误差的问题,提出一种考虑温度变化的对称铣削系统协同位姿误差预测与补偿方法。在恒温条件下,将对称铣削系统的工作空间划分为平动轴运动空间和旋转轴运动空间,提出一种在采样点误差已知情况下的误差预测算法|在变温条件下,通过测量分析对称铣削系统的热误差,提出一种能够快速确定任意温度下系统误差的方法。在误差补偿方面,提出一种递归算法补偿系统误差,并在对称铣削系统上进行实验。结果表明,在恒温条件下,补偿后的协同位置精度及姿态精度分别提高了78.42%和 57.03% ,在变温条件下分别提高了 79.14%和 62.79%,验证了该算法的有效性。 相似文献
18.
NAK80材料曲面高速铣削表面质量实验研究 总被引：1，自引：0，他引：1
通过实验，研究了模具制造业中常用的NAK80材料的表面粗糙度形成及曲面高速加工工艺参数的选择策略，分析了NAK80材料在高速铣削加工中以铣代磨的切削机理。结果表明，NAK80材料适合高速加工，在未来将成为高级橡塑模具的主要应用材料。 相似文献
19.
马红英 《石家庄职业技术学院学报》2011,23(4):24-27
比较了不同的切削模式和参数对数控铣削加工的影响.利用UG NX模拟了某型飞机加强角材冲压凹模的数控铣削加工过程,对生成的刀具轨迹路径进行了比较分析,得到了优化路径. 相似文献
20.
冯小军 《深圳职业技术学院学报》2004,3(1):1-6
为充分发挥数控机床的加工潜力和提高切削效率，作运用模糊控制方法研究了铣削加工过程的模糊自适应恒功率控制系统，并通过计算机仿真验证了控制方案的可行性；设计了系统的硬件和软件：进行了联机实验。实验结果表明，系统工作稳定可靠，平均可提高加工效率达20％以上。 相似文献