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Simulation and analysis of aerodynamics for high speed face milling cutters

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Science china(Technological Sciences) 2010年第9期53卷 2575-2580页

作者： JI ChunHui,LIU ZhanQiang & LIU LuNing school of mechanical engineering,shandong university,jinan 250061,china school of mechanical engineering Shandong University Jinan China

In high speed face milling,noise can be broadly categorized as idling noise and cutting *** noise mainly consists of aerodynamic noise.A mathematical model is developed based on the Ffowcs Williams-Hawkings *** noise predicted with the mathematical model compares well with the experimental *** characteristics of aerodynamic noise with the different model parameters (number of teeth,tooth spacing) and locations of observation points are *** directivity of noise is found and the peak value of sound power can be moved from the rotating frequency to higher *** investigation can provide theoretical foundation for the design of face milling cutters with low noise.

关键词： face milling cutter aerodynamic noise numerical simulation

Repetitious-Hot-Pressing Technique in Hot-Pressing Process

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Journal of Materials Science & Technology 2003年第5期19卷 486-488页

作者： Shixue SONG, Xing AI, Wei GAO and Jun ZHAO1)school of mechanical engineering, shandong university, jinan 250061, china2)school of Science, jinan university, jinan 250022, china school of mechanical engineering Shandong University Jinan 250061 China school of Science Jinan University Jinan 250022 China

A new pressing method was proposed for hot-pressing process. Experimental results indicated that the porosity in Al2O3/TiC/ Ni/Mo (hereafter called AI2O3/TiC composite) composite compacts decreases by 6% after adopting this new technique, compared to traditional hot-pressing technique under the same sintering temperature. The flexural strength and Vicker hardness increase from 883 MPa to 980 MPa and from 16 GPa to 21.1 GPa, respectively. A theoretical model was given to analyze the densification mechanism of the composite in the process of repetitious-hot-pressing.

关键词： Hot-pressing sintering Repetitious-hot-pressing sintering Composite

Relationship Between Thermal Shock Behavior and Cutting Performance of a Functionally Gradient Ceramic Tool

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厦门大学学报（自然科学版） 2002年第S1期41卷 61-62页

作者： ZHAO Jun, AI Xing, HUANG Xin-ping (school of mechanical engineering, shandong university, jinan 250061, china)

Based on the deep understanding of the requirements of cutting conditions on ceramic tools, a design model for functionally gradient ceramic tool materials with symmetrical composition distribution was presented in this paper, according to which an Al 2O 3-TiC functionally gradient ceramic tool material FG-1 was synthesized by powder-laminating and uniaxially hot-pressing technique. The thermal shock resistance of the Al 2O 3-TiC functionally gradient ceramics FG-1 was evaluated by water quenching and subsequent three-point bending tests of flexural strength diminution. Comparisons were made with results from parallel experiments conducted using a homogeneous Al 2O 3-TiC ceramics. Functionally gradient ceramics exhibited higher retained strength under all thermal shock temperature differences compared to homogeneous ceramics, indicating the higher thermal shock resistance. The experimental results were supported by the calculation of transient thermal stress field. The cutting performance of the Al 2O 3-TiC functionally gradient ceramic tool FG-1 was also investigated in rough turning the cylindrical surface of exhaust valve of diesel engine in comparison with that of a common Al 2O 3-TiC ceramic tool LT55. The results indicated that the tool life of FG-1 increased by 50 percent over that of LT55. Tool life of LT55 was mainly controlled by thermal shock cracking which was accompanied by mechanical shock. While tool life of FG-1 was mainly controlled by mechanical fatigue crack extension rather than thermal shock cracking, revealing the less thermal shock susceptibility of functionally gradient ceramics than that of common ceramics.

关键词： functionally gradient materials ceramic tool materials thermal shock resistance transient thermal stress cutting performance

Development of High-speed Machining Database with Case-based Reasoning

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厦门大学学报（自然科学版） 2002年第S1期41卷 48-49页

作者： WANG Zun-tong, LIU Zhan-qiang, AI Xing (school of mechanical engineering, shandong university, jinan 250061, china)

Applying high-speed machining technology in shop floor has many benefits, such as manufacturing more accurate parts with better surface finishes. The selection of the appropriate machining parameters plays a very important role in the implementation of high-speed machining technology. The case-based reasoning is used in the developing of high-speed machining database to overcome the shortage of available high-speed cutting parameters in machining data handbooks and shop floors. The high-speed machining database developed in this paper includes two main components: the machining database and the case-base. The machining database stores the cutting parameters, cutting tool data, work pieces and their materials data, and other relative data, while the case-base stores mainly the successfully solved cases that are problems of work pieces and their machining. The case description and case retrieval methods are described to establish the case-based reasoning high-speed machining database. With the case retrieval method, some succeeded cases similar to the new machining problem can be retrieved from the case-base. The solution of the most matched case is evaluated and modified, and then it is regarded as the proposed solution to the new machining problem. After verification, the problem and its solution are packed up into a new case, and are stored in the case-base for future applications.

关键词： case-based reasoning high-speed machining database case

Study on the Vibrational Power Flow Transmission Characteristics of Gearb ox

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厦门大学学报(自然科学版) 2002年第S1期 84-85页

作者： ZHANG Bing, SONG Kong-jie, SUN Ling-ling, QI Wen-guo (school of mechanical engineering, shandong university, jinan 250061, china)

Gearbox as an important source of noise and vibration, its structure-borne nois e has drawn more and more attentions and has become an important investigation t opic. The gearbox is extremely complicated mechanical equipment. In general, the profiles of gear teeth are not perfect. Together with the time-varying stiffne ss during tooth mesh, an in-plane force will be induced at the rim of a rotatin g gearwheel, which creates the vibration. These vibrations are transmitted throu gh the shafts, the bearings, and finally to the gearbox. At the same time, they will produce air-borne noise during tooth mesh, which radiate directly to the g earbox and through the gearbox radiate to the neighboring environment. In this paper, the overall dynamics of a gear system that includes a spur gear p air, shafts, bearings and a flexible gearbox is investigated. At first, the gear ed rotor system comprising gears, shafts, bearings and gearbox is set up and sim plified into a Source-Path-Receiver (SPR) model. Here, the rotating system inc luding the gears, shafts, primer mover and load is considered as the Source whil e the gearbox is regarded as the receiver and the bearings are treated as the Pa th. The dynamics of the SPR model is analyzed and the power flow transmitted fro m the source to the receiver is derived. Then the geared motor system is studied by finite element method (FEM), and corresponding mobility matrices are built b y choosing proper FEM model. Based on these data and the bearing’s mobility mat rix, the overall model of gearbox is developed using the component mobility meth od. At last the power flow transmission properties between substructures or subs ystem of gearbox are studied from the viewpoint of energy. The result will provi de the reliable computational foundation for improving the gearbox’s dynamical performance.

关键词： vibration isolation vibration measurement pow er flow

Diffusion and Oxidation Wear of PCBN Tool based on Thermodynamics

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Journal of Wuhan university of Technology(Materials Science) 2010年第2期25卷 265-271页

作者：邵芳 Binzhou Vacational College school of mechanical engineering Shandong University

The rules of diffusion wear and oxidation wear for PCBN cutting tools were analyzed based on thermodynamics theory. Dissolution concentrations in typical normal workpice materials of PCBN tool material at different temperature were then calculated. Diffusion reaction rules in high temperature were developed and analyzed using the Gibbs free energy criterion. The machining tests were conducted using the PCBN tools at different cutting speeds of 50, 95,100 and 180 m/min, feed of 0.1, 0.2 and depth of cut of 0.1, 0.8, 1, and 1.5 mm respectively on a PUMA300LM numerically-controlled lathe. It was found that the theoretical results were uniform with the experimental data, and the results will provide useful references for tool material design and selection.

关键词： thermodynamics PCBN tool diffusion wear oxidation wear

ANALYSIS OF THE MODES OF COLLABORATIVE DESIGN AND SYSTEM IMPLEMENTATION

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ANALYSIS OF THE MODES OF COLLABORATIVE DESIGN AND SYSTEM IMP...

MATHEMATICAL ANALYSIS OF TRANSVERSE VIBRATION OF CONICAL SPIRAL TUBE BUNDLE WITH EXTERNAL FLUID FLOW

2006年中国机械工程学会年会暨中国工程院机械与运载工程学部首届年会

作者： GAO Qi*, DU Zongzhan *school of mechanical engineering, shandong university, jinan 250061, china school of Electrical engineering, shandong university, jinan 250061, china

As the complexity and variety of products increase to satisfy increasingly sophisticated customers, modern product development is performed by cross-functional teams distributed geographically and tem

关键词： Collaborative design collaboration model project management workflow management.

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Journal of Hydrodynamics 2010年第6期22卷 816-822页

作者： YAN Ke GE Pei-qi SU Yan-cai BI Wen-bo Key Laboratory of High Efficiency and Clean mechanical Manufacture Ministry of Education School ofMechanical Engineering Shandong University Jinan 250061 China

The conical spiral tube bundle is a new type of heat transfer elements used to enhance heat transfer through flow-induced vibration. The effect of the external fluid flow on the transverse vibration of the conical spiral tube bundle is investigated with a mathematical method proposed in this article. Firstly, the natural vibration of the tube bundle is obtained by the hammering excitation method and the mode shapes of the transverse vibration are discussed. Then the effect of the external fluid flow on the transverse vibration of tube bundle is analyzed by a combination of experimental data, empirical correlations and FEM. The results show that in the frequency range from 0 Hz to 50 Hz, there exist six transverse vibrations. The external fluid flow has a significant effect on the frequency of the tube＇s transverse vibration, which are decreased by about 18% to 24% when the external fluid flow speed is 0.3 m/s.

关键词： conical spiral tube bundle mathematical model vibration characteristic FEM

长波子结构与短波子结构组成的复杂组合系统的振动分析(英文)

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山东大学学报（工学版） 2009年第1期39卷 87-91页

作者：纪琳山东大学机械工程学院山东济南250061

针对由长波子结构和短波子结构组成的复杂结构系统的中频振动的理论进行了分析.以往研究中使用基于子结构模态分析的方法来计算振动由长波子结构向短波子结构的传输,并通过一个简单的梁板耦合数例模型验证了其有效性.本文对该方法进行... 详细信息

针对由长波子结构和短波子结构组成的复杂结构系统的中频振动的理论进行了分析.以往研究中使用基于子结构模态分析的方法来计算振动由长波子结构向短波子结构的传输,并通过一个简单的梁板耦合数例模型验证了其有效性.本文对该方法进行了进一步的分析和探讨,并将之应用于一个更具普遍代表意义的梁板组合结构.结果表明该分析方法尤其适用于子结构间具有较大动态差异的情况.与基于子结构传递函数的传统计算方法相比,该方法能够显著降低所需要的计算成本.

关键词：长波子结构短波子结构中频振动复杂组合系统