Comparative Study on Cutting Performance of Chaser and Triangle-Shaped Inserts in Inconel 718 Turning

The effect of cutting teeth number on the cutting force,surface roughness,tool wear rate and the cutting chip shape characteristics is systematically evaluated.A novel five teeth chaser insert(C tool)which could turn the workpiece at five cutting points simultaneously is involved in comparison with the standard triangle shaped insert(T tool),in the purpose of solving the problems of cutting heat concentration and rapid tool failures in the Inconel 718 machining process.Comparative orthogonal cutting experiments of the C tool and T tool show that the cutting depth is the significant influencing factor of the cutting forces.Meanwhile,the five cutting teeth of the C tool show the effectiveness of dispersing the cutting forces as well as improving the cutting efficiency.The feed rate is the significant factor to affect the root-mean-square surface roughness(Ra)of workpiece machined by the T tool,while the significant influencing variable of Ra for the C tool is the cutting depth due to its unique tool geometry(0° rake angle)in the axial feeding process.Moreover,due to the dispersing effect,the cutting edges on the C tool exhibits lower tool wear rate than that of the T tool under the same axial feed.The chips are regular continuous long chips for the T tool,while the irregular continuous chips with the characteristic of saw-toothed profile are obtained due to its unique 0° rake angle.The C tool shows the valid potential for effectively dispersing the cutting heat and slowing down the tool wear rate in the Inconel 718 machining process.     

An Optimization Method for Simulator Using Probability Statistic Model

IntroductionSimulator is an indispensable tool in earlyphase of embedded system design.It providesstatistic for system functional verification.Fur-thermore,the development of system-on-chip(SOC)makes embedded system customized forspecific application possible.In order to make sys-tem meet constraints of performance,power con-sumption and chip area without wasting more costand time,simulator is often used to evaluate andmodify candidate architectures.Simulation techniques are divided into two…     

Surface spline interpolation method for thermal reconstruction with limited sensor data of non-uniform placements

With the characteristic size reducing as well as the power densities exponentially increasing, elevated chip temperatures are true limiters to the performance and reliability of integrated circuits. To address these thermal issues, it is essential to use a set of on-chip thermal sensors to monitor temperatures during operation. These temperature sampling results are then used by thermal management techniques to appropriately manage chip performance. In this paper, we propose a surface spline interpolation method to reconstruct the full thermal characterization of integrated circuits with non-uniform thermal sensor placements. We construct the thermal surface function using the mathematical tool of surface spline with the matrix calculation of the non-uniform sample data. Then, we take the coordinates of the points at grid locations into the surface function to get its temperature value so that we can reconstruct the full thermal signals. To evaluate the effectiveness of our method, we develop an experiment for reconstructing full thermal status of a 16-core processor. Experimental results show that our method outperforms the inverse distance weighting method based on dynamic Voronoi diagram and spectral analysis techniques both in the average absolute error metric and the hot spot absolute error metric with short enough runtime to meet the real-time process demand. Besides, our method still has the advantages such as its mathematical simplicity with no need of prehprocess.     

Study on Real-time Look-ahead and Adaptive Parametric Curve Interpolator

The principle of real-time look-ahead was introduced and analysed. An adaptive parametric curve interpolator with a real-time look-ahead function was developed for non-uniform rational B-spline (NURBS) curves interpolation, which considering the maximum acceleration/deceleration of the machine tool. In order to deal with the acceleration/deceleration around the feedrate sensitive corners, the look-ahead function was designed and illustrated. It can detect and adjust the feedrate adaptively. With the help of real-time look-ahead, the acceleration/deceleration can be limited to the range of the machine tool capacity. Thus, feedrate fluctuation is reduced. A NURBS curve interpolation experiment was provided to verify the feasibility and advantages of the proposed interpolator with a real-time look-ahead function.     

Research and Development of a New Calibration Tool for Electronically Controlled Engine Based on KWP2000

Today‘s vehicles use electronic control units (ECU) to control engine/transmission, body and other amenities. All the vehicle performance depends on a lot of physical values and influence factors. This leads to a large number of control and regulation parameters in the ECU software. The ultimate objective of calibration work is the optimum determination of these parameters. Qualitatively excellent results can only be achieved in a shorter time by using a highly efficient calibration system. This paper provided an overview of a new calibration tool based on KWP2000 and gave an example calibration with this tool.     

Hardware architecture design of block-matching and 3D-filtering denoising algorithm

Block-matching and 3D-filtering(BM3D) is a state of the art denoising algorithm for image/video,which takes full advantages of the spatial correlation and the temporal correlation of the video. The algorithm performance comes at the price of more similar blocks finding and filtering which bring high computation and memory access. Area, memory bandwidth and computation are the major bottlenecks to design a feasible architecture because of large frame size and search range. In this paper, we introduce a novel structure to increase data reuse rate and reduce the internal static-random-access-memory(SRAM) memory. Our target is to design a phase alternating line(PAL) or real-time processing chip of BM3 D. We propose an application specific integrated circuit(ASIC) architecture of BM3 D for a 720 × 576 BT656 PAL format. The feature of the chip is with 100 MHz system frequency and a 166-MHz 32-bit double data rate(DDR). When noise is σ = 25, we successfully realize real-time denoising and achieve about 10 d B peak signal to noise ratio(PSNR) advance just by one iteration of the BM3 D algorithm.     

A Simplified Model for Vibration Analysis of Diesel Engine Crankshaft System

IntroductionThe design of modern diesel engine is requiredto make noise and vibration as light as possible.Inorder to successfully control the noise and vibra-tion,the vibrations of engine crankshaft must beestimated and analyzed.Dynamic simulation is avery powerful tool for ranking different design al-ternatives,so it is necessary to develop an analyti-cal model for the accurate prediction of dynamicbehavior of engine crankshaft.In earlier research,the equivalent model and the continuous beam…     

FUZZY REQUIREMENT BASED STRATEGY OF QoS SERVICE FOR BROADBAND TELECOMMUNICATION NETWORKS

IntroductionThere are many strategies for Qo S service inbroadband telecommunication networks[1] . Withthe fast evolution of chip and software techniques,the telecommunication networks are running withmore and more throughputcapabilities and self- ad-ministration capabilities.On the other hand,theapplication of methodologies based on concepts ofartificial intelligence in the telecommunication fieldis being more and more frequently used[2 ] .Thispaper gives a new strategy to evaluate the Qo S…     

EXTRACTING MODAL PARAMETERS FROM STRUCTURES UNDERGOING AMBIENT EXCITATION

IntroductionModal analysis is now a basic tool for thestudy of dynamic behaviors of structures.In moni-toring,modal fitting or optimum design techniquesis largely made of the modal information,con-tributing to the development of many methods forparameters identification.These modal analysistechnique can be classified into two families:artifi-cial excitation based methods and natural excitationbased methods.Artificial excitation based methodsare the oldest and the most employed and calledtradit…     

Online Mind-Map as Interface of Electronic Resource Integration and Sharing

The paper aims to research on online mind map as interface of learning resource integration and sharing.We developed a web application that provides a interface to allow users to create a knowledge mind map.With the online mind mapping tool,the electronic learning resource will be discovered and shared in the form of subject-oriented package,it is more flexibly than the other E-Learning systems,and the interaction and cooperation of the users are strengthened to some extent.     

预裂爆破技术在路堑边坡施工中的应用

根据大量的现场预裂爆破试验,研究了预裂爆破技术在路堑边坡施工中的应用.从现场的实际情况出发,通过现场的爆破试验,对爆破方案进行了优化,取得了良好的爆破效果.对岩土开挖工程的爆破施工具有很重要的指导意义,同时取得了明显的社会和经济效益.     

空间润滑装置高压雾化喷嘴的喷雾特性

为解决航天器在空间轨道运行时润滑失效的问题,将高压直射式雾化喷嘴应用到空间润滑领域,利用流体动力学软件CFD-ACE+2009,建立了直射式雾化喷嘴气液两相流模型,在此基础上,对润滑油喷雾流的生成过程进行数值模拟,并考察了喷嘴处液体流动速度及压力的分布情况.通过2种高粘度液体NYE 2001、Krytox 143AB与柴油的对比,分析了液体物理参数对液体内部压力传递及流速变化的影响.数值模拟结果表明:航空润滑油NYE 2001的高粘度严重阻碍入口压力的传递,当入口压力为15 MPa时,1 mm长的喷嘴末端压力下降到0.42 MPa,降幅达到97.2%;过高的液体粘度和过长的喷嘴,对液体喷雾流的形成产生不利影响.     

Mark5型船舶主机油雾浓度探测器仿真研究

文章以Mark 5型船舶主机油雾浓度探测器为仿真对象,以Visual C#为仿真开发平台,开发了船舶主机油雾浓度探测训练仿真系统,实现了该探测器的仿真运行与维护管理训练功能.仿真运行结果表明该系统满足STCW公约要求,可以完成实训及评估功能.     

故障树分析法在船舶细水雾灭火系统故障查找流程图设计中的应用

文章通过对船舶细水雾灭火系统的工作过程及常见故障的分析,提出了用故障树分析法来对船舶细水雾灭火系统进行故障诊断,建立了船舶细水雾灭火系统故障树及其故障查找流程图。通过故障查找流程图轮机员能够快速准确地找出故障并及时排除故障,保证了船舶的安全航行。     

公路路堑边坡防护方法研究

重点探讨了公路边坡防护技术,综合分析了常见坡面防护技术的防护形式、特点及其适应性,给出了边坡防护设计的基本原则,并在此基础上探讨其发展趋向。     

宜水高速公路路堑边坡光面爆破施工

宜水高速公路D合同段路堑高边坡采用光面爆破技术,取得较好的爆破效果,获得稳定、美观的路堑高边坡.     

一种难加工材料的斜角切削过程的数值模拟

参数化建模在仿真切削过程中是行之有效的方法。通过接口设计,系统实现了在Marc中对斜角切削方式的参数化建模。基于金属切削理论和有限元分析原理。借助于有限元方法及材料弹塑性变形理论。针对斜角切削方式,通过建立几何模型、材料模型、刀屑摩擦模型、热控模型和切屑分离准则,采用有限元分析软件Marc,对一种难加工材料的切削过程进行数值模拟,得到在不同切削条件下的切削区应力场、温度场。通过对数值模拟后切削力的结果与实验得到的数据进行比较,验证了所建模型的合理性。     

Wear Mechanisms of Ceramic Inserts in Machining Nickel-Based Superalloy

The performances of ceramic inserts in cutting nickel-based alloy were investigated. A new cutting test-bed was devised and used to deburr. The burr height on the working surface with notch wear in deburring cutting was compared with that in normal cutting. The impact force, impact pressure, and impact frequency of the saw-tooth-shaped chip edge on rake face and cutting edge at different speeds were calculated, and the influence of chip edge on notch wear formation was analyzed. A new tool design for reduci...     

模具制造中的高速切削技术分析

随着国家高新技术产业的快速发展,对模具制造业也提出较高要求,传统的模具制造通常采用先铣削再淬硬,然后电火花加工及后续抛磨,制造工艺复杂、加工效率低、能源消耗高、污染较大。高速切削技术应用在模具制造业中,可以直接通过高速硬切削获得较高的精度及表面质量,高速切削技术制造工艺过程简单、加工效率较高、能源消耗少、污染较小且具有良好的经济效益,因此,适宜在模具加工中广泛推广应用。     

焊割作业典型事故原因分析

焊割技术发展迅速,运用广泛,事故也不断发生。文章对其原因进行了详细分析,以使管理和作业人员对其有一定的认知度,从而达到降低事故发生率的目的。