超声振动平面磨削的表面残余应力数值模拟

应用Deform-3D有限元软件进行具有负前角磨削刃的单颗磨粒磨削加工过程仿真,并设计制造了旋转轴向超声振动平面磨削实验装置进行工艺实验,分别得到45钢在不同磨削工况下的磨削表面残余应力仿真值和实验值,通过对比分析,发现两者的相对误差在2.47%~16.93%之间,从而验证了所建磨削表面残余应力有限元模型的正确性。仿真结果表明:普通磨削和超声磨削在工件表面均产生残余压应力,且轴向残余压应力显著大于磨削方向残余压应力;表面残余压应力随着振幅、磨削深度、磨粒负前角和振动频率的增加而增加,随着砂轮线速度的增加而减小。     

基于热力耦合的磨削残余应力仿真与试验研究

基于淬硬轴承钢GCr15平面磨削试验,通过X射线衍射法对磨削表面残余应力进行测量。依据热弹塑性理论和Johnson-Cook塑性模型,建立了平面磨削有限元模型,研究了不同移动热源模型对磨削残余应力仿真结果的影响。结果表明,不同的热源模型对残余拉应力层的深度无显著影响,椭圆热源模型计算的残余应力与实验测量值最为吻合。     

基于ANSYS的磨削残余应力场仿真研究

作为影响工件表面完整性的关键因素之一,残余应力影响工件强度,在制造时会导致产生变形和开裂等工艺缺陷,同时在制造后的自然释放过程中也会导致材料的疲劳强度、应力腐蚀等力学性能降低。本文借助有限元分析软件ANSYS,采用热—力顺序耦合方法,建立了平面磨削残余应力场的有限元模型。该模型能够动态反映磨削加工过程中工件表层残余应力的变化情况。在此基础上,分析了不同磨削参数对工件表层残余应力的影响,从计算机仿真角度对磨削加工工艺参数进行了优化。仿真结果表明,在磨削过程中,工件表层同时存在着残余拉应力和残余压应力,与其他磨削参数相比,磨削深度对残余应力的影响最为显著。     

螺旋锥齿轮热处理和磨削残余应力有限元分析

为了对螺旋锥齿轮加工过程中表面残余应力进行分析和控制,应用DEFORM和ABAQUS软件建立螺旋锥齿轮热处理和磨削仿真模型,研究热处理和磨削过程残余应力提取与叠加方法,分析磨削速度、磨削切深、进给速度对残余应力的影响规律。通过磨削加工试验,验证有限元仿真的可信性,为齿轮热处理和磨削工艺参数的确定提供理论指导。     

弧齿锥齿轮磨削齿面残余应力生成及影响因素研究

弧齿锥齿轮齿面残余应力是磨削条件下各种因素综合作用而产生的。建立了影响磨削残余应力的磨削基本参数、磨削热和磨削力的数学模型。在有限元3D单齿模型基础上,进行了弧齿锥齿轮磨削残余应力的有限元仿真与分析,并试验验证了此方法是可行的。结果表明:残余压应力呈现在弧齿锥齿轮齿面上,而残余拉应力在齿内;磨削残余应力与磨削深度、砂轮速度、展成速度、磨削液有关;磨削残余应力的降低能有效地预防磨削裂纹。     

直齿轮成形磨削齿面残余应力计算与实验验证

磨削加工齿轮的残余应力状态对齿轮使役性能有较大影响,磨削后齿面的表面残余应力准确预测与计算是齿轮抗疲劳制造的重要内容。基于成形磨削运动分析及热力耦合有限元仿真计算方法,提出了齿轮成形磨削加工齿面残余应力计算方法。开展成形磨削实验,测量磨削后齿面的残余应力,对比分析残余应力实验测量值与有限元计算值,分析了磨削加工参数与残余应力的关联规律。结果表明,提出的成形磨削齿面残余应力计算方法得到的计算值与实验测试结果具有较好的一致性;在成形磨削中,砂轮进给深度越大,齿面残余拉应力越小。     

超细硬质合金磨削残余应力仿真与实验研究

本文进行了金刚石砂轮平面磨削超细硬质合金残余应力有限元仿真,通过ANSYS软件中的APDL参数设计语言,完成了对超细硬质合金材料建模、网格划分、加载、求解的整个过程,并对超细硬质合金磨削表面残余应力进行了实验论证,得出了不同磨削参数下的磨削残余应力值,对比了不同目数砂轮和不同WC晶粒硬质合金在同一磨削参数下的残余应力值。研究发现,目数小的砂轮磨削时产生的残余应力值要大,WC晶粒度越小,磨削的残余应力值越大。结果表明,实验结果与有限元模拟大致相同。     

陶瓷磨削残余应力对表面性能的影响

陶瓷零件的磨削表面必然要附加一层残余压应力 ,其对零件的使用性能影响较大。本文主要针对陶瓷材料磨削表面残余应力对疲劳磨损和表面硬度的影响进行实验研究。试验结果表明 :与金属材料相比 ,Zr O2 陶瓷材料的磨削残余应力对零件的摩擦磨损性能的影响要小得多。磨削、研磨及加热三个试件组的磨损量随摩擦时间呈现一定的变化规律。残余拉应力在一定程度上加速陶瓷零件的磨损 ,残余压应力可适当减缓陶瓷零件的磨损 ,其数值变化对零件性能的影响很小。随着残余压应力值的增加 ,表面硬度值也在逐渐增加 ,当残余压应力增加到一定值后表面硬度值开始下降。     

齿根过渡圆弧对全齿槽成形磨削温度和残余应力影响的研究

在齿轮全齿槽成形磨削过程中,考虑相邻三个热源（齿底热源、过渡圆弧热源、齿廓热源）的耦合效应,建立了磨削温度场的三维有限元仿真模型,计算了全齿槽成形磨削温度,并在此基础上,采用基于热-结构耦合的有限元方法计算了磨削引起的残余应力,分析了磨削温度场和残余应力场的分布特征,以及齿根过渡圆弧的大小对磨削温度和磨削后齿根处残余应力分布的影响。结果表明,过渡圆弧半径对磨削温度的影响相对较小,但对齿根处残余应力的影响较大;与没有过渡圆弧的齿槽相比,当过渡圆弧半径超过2 mm时,磨削后齿根最大残余应力降低20%以上。实验测量结果与有限元仿真结果一致,证明了模拟结果的正确性。     

预应力淬硬磨削工件表面层质量试验研究

从抗疲劳制造与绿色制造的观念出发,融合预应力磨削与磨削淬硬技术原理,提出了将残余应力控制、表面淬火及磨削三者集成于一体的预应力淬硬磨削技术理论与方法。对45钢试件进行了预应力淬硬磨削加工试验,以工件淬硬层表面残余应力、硬度及粗糙度为研究对象,与相同条件下的磨削淬硬工艺试验结果进行了对比分析。结果表明：预应力淬硬磨削工艺可增大工件表面残余压应力,减小拉应力,其工件表面残余应力状态优于磨削淬硬工艺;预应力淬硬磨削工件表面硬度可以达到基体硬度的3倍左右,而工件表面粗糙度小于磨削淬硬工艺工件表面粗糙度。因此,在相同的加工条件下,预应力淬硬磨削工艺比磨削淬硬工艺具有更好的抗疲劳性、耐腐蚀性及表面完整性。     

奥利康摆线齿锥齿轮铣刀盘刀齿刃磨方法及加工仿真

根据磨轮与刀齿型面的接触条件,提出了奥利康摆线齿锥齿轮铣刀盘条形刀五轴刃磨加工的刀位点计算方法。利用Vericut软件构建了虚拟机床模型和加工环境,进行条形刀五轴刃磨仿真,验证了刀位点和NC代码的正确性。     

Geometric modeling and grinder design for toroid-cone shaped cutters

This paper presents a set of mathematical models for the design and manufacture of the helical flute and cutting-edge curve of a toroid-cone shaped revolving cutter. The study not only considers the section profile and relative feeding velocities of the grinding wheel used in the NC machining of the cutter, but also addresses the deviation of the cutting-edge curve, the residual material which exists between adjacent flutes, and the lack of cutter land. Through a process of numerical simulation, a compensation technique is developed which reduces the residual material and rebuilds the missing land. The accuracy of the theoretical models is verified by means of an experimental machining test using a WALTER CNC grinding machine. The experimental results are in good agreement with those predicted theoretically, thereby confirming the accuracy and reliability of the proposed models. This study serves as a valuable reference for researchers investigating the NC machining of cutters with special forms.     

基于Matlab的数控加工代码仿真检验

为保证实际数控加工的顺利进行 ,需要采用仿真加工技术对数控加工代码的正确性进行检验。在研究数控加工代码仿真检验技术的基础上 ,开发了基于Matlab平台的数控工具磨床仿真加工系统 ,实现了复杂形状刀具数控磨削加工代码的仿真检验。     

NUMERICAL ANALYSIS AND COMPUTER SIMULATION OF FORMATION OF RESIDUAL STRESSES IN GRINDING PROCESS

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Manufacturing models for design and NC grinding of truncated-cone ball-end cutters

This paper presents a set of mathematical models for the design and manufacture of the helical flute and cutting-edge curve of a pair of truncated-cone ball-end cutters. The section profile and relative feeding velocities of the grinding wheel in NC machining of the cutter are deduced. In addition, the deviation of the cutting-edge curve, residual material and the land lack caused by the modified radial feeding velocity are taken into consideration. In order to finish the residual material and rebuild the land of the cutter, the technique for compensation has been developed in this research. The accuracy of the theoretical models is verified by means of an experimental machining test using a WALTER CNC grinding machine. The experimental results are in good agreement with those predicted theoretically, thereby confirming the accuracy and reliability of the proposed models. This study serves as a valuable reference for researchers investigating the NC machining of cutters with special forms.     

<Emphasis Type="Bold">CNC Rake Grinding for a Taper Ball-End Mill with a Torus-Shaped Grinding Wheel</Emphasis>

A new grinding method using a torus-shaped grinding wheel and a machining path generation method with a novel moving coordinate system are proposed. With this new grinding method, the smooth spiral rake surface of a taper ball-end mill with constant helical angle and constant normal rake angle can be formed during one grinding process and the normal rake angle can be obtained accurately. The novel moving coordinate system is established based on taking account of both the cutting edge curve and the cutter body surface. By means of the novel moving coordinate system, the machining path generation becomes very simple. The proposed grinding method and the machining path generation method are verified by 3D simulation results.     

残余应力引起的铣削变形有限元分析

应用弹性力学理论推导出了二维连续铣削过程中工件内应力再分布及其引起变形的计算递推公式.解决了有限元建模、初始应力加载、变形评估等仿真关键技术,建立了残余应力引起铣削变形的二维有限元仿真模型.最后对实例进行了仿真计算,分析了残余应力引起的加工变形规律,并用解析法对仿真结果的进行了验证.     

基于OpenGL无心外圆磨削仿真系统的研究

无心磨削是一种精密、高效的加工方法,在机械制造领域占有重要地位,以切入式外圆无心磨削为研究对象,介绍了仿真系统中各功能模块,对系统开发过程中所使用到的技术要点进行探讨,并对3DS模型在仿真系统中的读取与重现进行了分析,采用OpenGL技术实现了无心外圆磨削加工过程的仿真系统,提出了根据工件中心高的理论优化值计算托板高度的方法,在时域中对工件真圆度和磨削力进行了仿真,为进一步研究无心磨削的动态特性和提高磨削加工精度提供了依据。     

Mathematical modeling and machining parameter optimization for the surface roughness of face gear grinding

Face gear is an important part in the power transmission of helicopter, but its grinding is a difficult problem. In order to enhance the finishing machining surface quality of face gear, the mathematical formula of the residual height of motion trajectory of abrasive grains was obtained, and the model of grinding surface roughness of face gear was corrected. In addition, machining parameter optimization for grinding surface roughness on a five-axis blade grinding machine was investigated by orthogonal experiment method. The experiment results indicated that disk wheel spindle speed and feed velocity of the disk wheel are more significant effect factors among the three factors. The calculation results of model showed that the maximum error comparing with the experiment results is not more than 13.5 %, which suggests that the mathematical model is reasonable.     

Design and NC Machining of Concave-Arc Ball-End Milling Cutters

The paper presents a geometric modelling approach for the precision design and NC machining of a concave-arc ball-end milling (CABEM) cutter which is an important tool for mould-making industries. This paper presents systematic models of the cutting edge, helical groove, and grinding wheel design for the NC machining of a CABEM cutter. Both the normal to the revolving axis and the tangent to the groove, are used to derive the required precision sectional profiles of the grinding wheel. In compliance with the maximal sectional radius of the cutter, the profile of the groove section and both the radial and axial cutting speeds of the grinding wheel are computed in sequence. Using the computer simulation results of the groove actually obtained, this paper proposes a method to resolve the problems of the residual revolving surface and the narrow cutting edge strip. This paper is intended to serve as a reference for the design and NC machining of cutters of this type .