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E. J. A. Armarego 《Machining Science and Technology》2013,17(2):191-211
ABSTRACT The need for quantitatively reliable predictive models for the many technological machining performance measures to optimize the economic performance of machining operations, and to design machine tools and cutting tools that enhance this economic performance, has been highlighted. Also highlighted is the formidable task of establishing the required quantitative technological performance data and equations, and the gap between theory and practice. The development and generic nature of the “unified or generalized mechanics of cutting approach” to technological performance prediction for the wide spectrum of machining operations is presented and discussed in this paper. Suggestions for overcoming some practical difficulties and extending the scope of this predictive modeling approach are also considered. 相似文献
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磨料水射流切割质量的参数化模型 总被引:5,自引:0,他引:5
作为一种新型的冷态高能束切割技术,磨料水射流(AWJ)以其独特的优点得以广泛应用,但其本身的技术特性使得切割质量存在不足。本文从能量角度分析了AWJ切割质量的影响因素,结合实验数据采用回归分析方法建立了AWJ切割质量与工作压力、切割速度、磨料流量的半经验模型,能够可以满足工程需要。为AWJ切割工艺参数优化选择及切割质量的评价、分析提供了理论基础。 相似文献
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利用超高压水射流切割试验系统,在80~280MPa压力范围内进行淹没磨料水射流切割试验研究,通过试验及数据分析,验证了后混合淹没磨料射流切割的可行性,得出了磨料粒径和质量流量、射流压力、靶距、切割横移速度等参数对射流切割性能的影响规律,对于脆性和塑性材料,试验中各参数对切割深度的影响基本一致.结果表明:在试验给出的工况条件下,磨料流量存在最佳值,在一定范围内切割深度随磨料流量增加而增加,当磨料流量达到一定值后,切割深度随流量增加反而下降;切割深度与射流压力基本呈线性增长关系;随着靶距的增大,切割深度逐渐减小;切割深度随切割速度的增加呈指数衰减趋势,并且相同试验工况下淹没射流切割深度要大于非淹没状态.试验结果为超高压淹没磨料水射流的实际应用和研究提供了参考. 相似文献
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磨料水射流加工去除模型研究 总被引:11,自引:0,他引:11
采用ANSYS Fluent对磨粒流场进行瞬态CFD仿真,得到射流过程中磨粒的分布和速度;并研究射流加工区磨粒运动机制,研究表明,新型后混合式磨料水射流加工中磨粒很容易穿过射流加工的静压区直接与工件发生作用进而去除材料。建立磨粒冲击塑性材料的冲击变形磨损模型,并结合Finnie塑性剪切磨损去除模型建立磨料水射流加工去除模型,模型表明,射流加工中心区域的材料去除量最高。根据新型后混合式磨料水射流系统进行塑性材料的磨料水射流加工试验,结果表明,射流加工中心区域材料去除最高,这是由于射流加工中心区域磨粒冲击角度较大、磨粒速度较高,材料以冲击变形磨损去除为主;远离射流冲击中心区域材料去除较低,材料以剪切磨损去除为主,与磨料水射流加工去除模型是完全一致的,证实磨料水射流加工去除模型的正确性。 相似文献
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本文介绍了前混合式磨料射流切割机的结构,工作原理以及用该机对金属和非金属材料进行的切割试验,指出射流工作压力、喷射靶距、喷嘴横移速度、磨料重量比浓度等是影响工作能力的主要因素,喷嘴直径及其内腔结构、磨料粒子尺寸等也是影响割缝宽度及表面形态的因素.试验对此表明,它比纯高压水射流和后混合式磨料射流切割机性能优越,是一种新型的、有广阔应用前景的工业切割设备. 相似文献
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This paper presents and discusses an experimental investigation of abrasive waterjet (AWJ) cutting of alumina ceramics with
controlled nozzle oscillation. Particular attention is paid to the effect of small oscillation angles on the various cutting
performance measures. It is found that nozzle oscillation at small angles can equally improve the major cutting performance
measures, if the cutting parameters are correctly selected. However, under high water pressures, high nozzle traverse speeds
and large oscillation frequencies, nozzle oscillation may cause a decrease in some major cutting performance measures, such
as surface finish. Plausible trends of cutting performance with respect to the process parameters are further considered.
Finally, a predictive mathematical model for the depth of cut is developed and verified. 相似文献
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为提高磨料水射流加工性能和延长喷嘴使用寿命,基于欧拉-欧拉方法和离散粒子模型,利用CFD仿真技术探究磨料水射流喷头内部的三相流运动,建立磨料水射流喷头的物理模型,并通过与文献实验结果对比,验证模型的可靠性。通过自定义粒子圆度系数,利用CFD模拟分析粒子圆度系数对粒子出口速度及管壁磨损率的影响。结果表明:射流压力和磨料圆度越大,磨料出口速度越大,喷嘴内磨损越小;磨料流量和磨料圆度系数越大,磨料出口速度越小,喷嘴内磨损越大;磨料尺寸越小和磨料圆度越大,磨料出口速度越大,喷嘴内磨损也越大;水射流切割过程中的深宽比随着压力增大而增大,随着横移速度和靶距的增加而减小,随着粒子圆度的增大而增大。 相似文献
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Dr A. A. El-Domiaty M. A. Shabara A. A. Abdel-Rahman A. K. Al-Sabeeh 《The International Journal of Advanced Manufacturing Technology》1996,12(4):255-265
Abrasive waterjet cutting operates by the impingement of a high-velocity abrasive-laden waterjet against the workpiece. The jet is formed by mixing abrasive particles with high-velocity water in mixing tubes and is forced through a tiny sapphire orifice. The accelerated jet exiting the nozzle travels at more than twice the speed of sound and cuts as it passes through the workpiece.This cutting process is being developed as a net-shape and near-net-shape machining process for cutting many metals and hard-to-machine materials. The narrow kerf produced by the stream results in neither delimitation nor stresses along the cutting path. This new technology offers significant advantages over traditional processes for its ability to cut through most sections of dense or hard materials without the need for secondary machining, to produce contours, and to be integrated into computer-controlled systems.The abrasive waterjet cutting process involves a large number of process and material parameters which are related to the waterjet, the abrasive particles, and workpiece material. Those parameters are expected to effect the material removal rates and the depth of cut. The purpose of the present work is to propose a model which is capable of predicting the maximum depth of cut for different types of materials using different process parameters. A comparison of the results of the proposed model and the models reported in the literature is introduced along with a discussion of the limitations of those models.On leave from: Mechanical Engineering Department, Suez Canal University, Egypt.On leave from: Industrial Production Engineering Department, Mansoura University, Egypt.On leave from: Mechanical Power Engineering Department, Alexandria University, Egypt. 相似文献
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将磨料浆体射流技术应用于切割领域,研制出相应的切割机床,避开了国外该项技术中的高压动密封问题,并对该机床的切割性能进行了正交试验,同时,将磨料浆体射流机床与前混合磨料水射流机床的切割性能进行了比较研究, 研究表明,影响磨料浆体射流切割性能的主要因素依次是切割速度、切割压力和靶距;在相同切割条件下,磨料浆体射流机床与前混合磨料水射流机床的切割力大致相同,但磨料浆体射流机床的切割质量明显好于后者,切割能耗大大低于后者。 相似文献
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将评价切削液加工性能的实机试验方法归纳为工序节拍方式、参数调整方式、综合优化方式三类,并论述了各自的特点、评价指标与应用场合;提出了设计和实施实验室模拟评价试验的要点;介绍了两种在通用机床上进行的模拟切削试验方法以及攻丝扭矩模拟评定试验机。 相似文献