ANALOG SIMULATION OF DYNAMIC RESPONSE IN DRY FRICTION PAIR BY THERMODYNAMICS

ＡＮＡＬＯＧＳＩＭＵＬＡＴＩＯＮＯＦＤＹＮＡＭＩＣＲＥＳＰＯＮＳＥＩＮＤＲＹＦＲＩＣＴＩＯＮＰＡＩＲＢＹＴＨＥＲＭＯＤＹＮＡＭＩＣＳ￥ＪｉｎＣｈａｎｇｓｈａｎ；ＥＫａｎｎａｔｅｙ－Ａｓｉｂｕ，Ｊｒ（ＨａｒｂｉｎｉｎｓｔｉｔｕｔｅｏｆＴｅｃｈｎｏｌｏｇ...     

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

ＮＵＭＥＲＩＣＡＬＡＮＡＬＹＳＩＳＡＮＤＣＯＭＰＵＴＥＲＳＩＭＵＬＡＴＩＯＮＯＦＦＯＲＭＡＴＩＯＮＯＦＲＥＳＩＤＵＡＬＳＴＲＥＳＳＥＳＩＮＧＲＩＮＤＩＮＧＰＲＯＣＥＳＳ①ＨｕＨｕａｎａｎＺｈｏｕＺｅｈｕａＣｈｅｎＣｈｅｎｇｚｈｏｕＳｏｕｔｈＣｈｉｎａ...     

FREQUENCY DOMAIN ANALYSIS AND COMPUTER SIMULATION OF PRESSUREPULSATION RESONANCE IN HIGHPRESSURE PIPI

ＦＲＥＱＵＥＮＣＹＤＯＭＡＩＮＡＮＡＬＹＳＩＳＡＮＤＣＯＭＰＵＴＥＲＳＩＭＵＬＡＴＩＯＮＯＦＰＲＥＳＳＵＲＥＰＵＬＳＡＴＩＯＮＲＥＳＯＮＡＮＣＥＩＮＨＩＧＨＰＲＥＳＳＵＲＥＰＩＰＩＮＧＮＥＴＷＯＲＫＹａｎＳｉａｎｇａｎ；ＺｈｅｎｇＷｅｉ；ＬｅｉＫａｎ...     

VEHICLE DYNAMIC ANALYSIS SIMULATION－MODELLING THEORY AND ENGINEERING APPLICATION

ＶＥＨＩＣＬＥＤＹＮＡＭＩＣＡＮＡＬＹＳＩＳＳＩＭＵＬＡＴＩＯＮ－ＭＯＤＥＬＬＩＮＧＴＨＥＯＲＹＡＮＤＥＮＧＩＮＥＥＲＩＮＧＡＰＰＬＩＣＡＴＩＯＮＶＥＨＩＣＬＥＤＹＮＡＭＩＣＡＮＡＬＹＳＩＳＳＩＭＵＬＡＴＩＯＮ－ＭＯＤＥＬＬＩＮＧＴＨＥＯＲＹＡＮＤＥ...     

ANALYSIS SOLUTION OF BULGING CONVEXITY OF THE HYDRAULIC ELASTIC BULGING ROLL

ＡＮＡＬＹＳＩＳＳＯＬＵＴＩＯＮＯＦＢＵＬＧＩＮＧＣＯＮＶＥＸＩＴＹＯＦＴＨＥＨＹＤＲＡＵＬＩＣＥＬＡＳＴＩＣＢＵＬＧＩＮＧＲＯＬＬＡＮＡＬＹＳＩＳＳＯＬＵＴＩＯＮＯＦＢＵＬＧＩＮＧＣＯＮＶＥＸＩＴＹＯＦＴＨＥＨＹＤＲＡＵＬＩＣＥＬＡＳＴＩＣＢＵＬＧ...     

DYNAMIC MATHEMATICAL MODEL OF CHEMICAL COMPOSITION FOR MELTED IRON IN CUPOLA AND MICROCOMPUTER SIMULATION

ＤＹＮＡＭＩＣＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＣＨＥＭＩＣＡＬＣＯＭＰＯＳＩＴＩＯＮＦＯＲＭＥＬＴＥＤＩＲＯＮＩＮＣＵＰＯＬＡＡＮＤＭＩＣＲＯＣＯＭＰＵＴＥＲＳＩＭＵＬＡＴＩＯＮＤＹＮＡＭＩＣＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＣＨＥＭＩＣＡ...     

INVERSE KINEMATIC AND DYNAMIC ANALYSIS OF A 3—DOF PARALLEL MECHANISM

According to the structure character of the passive sub-chain of the 3TPS-TP parallel mechanism, the kinematic constraint equations of the movable platform are established, based on which the closed-form inverse kinematics formula of the parallel mechanism are presented. Through parting the spherical joints of the active sub-chains and using the force and moment equilibrium of both the active sub-chains and passive sub-chain, the constraint forces acting on the parted joints are determined. Subsequently, the analytic expressions of the actuator driving forces are derived by means of the force equilibrium of the upper links of active sub-chains.     

FEM AND EXPERIMENTAL ANALYSIS OF THE ACTUATOR ‘BUTTERFLY MODE’ IN A HARD-DISK DRIVE

As the recording track density increases in hard-disk drives, the off-track error-rejection capability of the servo controller must also be increased. The high rejection capability is achieved by increasing the servo bandwidth; however, the ability to extend the bandwidth is limited by the actuator's structural resonance. One particular resonance mode of interest is the so-called ‘butterfly mode’ where it exhibits as the primary resonance with a 180° phase in the structural (open-loop) transfer function plot. The factors influencing the butterfly mode were investigated using finite element analysis and confirmed by prototype testing. Although the mass-to-stiffness ratio in bearing cartridge pivot and the sway mode of the actuator structure by themselves were at a high enough frequency range, it was observed that the coupling effect in the pivot and actuator structure limited the frequency that it can be achieved. With the knowledge gained from the analysis, it is now possible to design an actuator to enable the high servo bandwidth required to follow track densities of more than 50 kilotracks per inch (kTPI) without the need for a dual-stage actuator.     

ENERGY-SAVING TYPE OF HYDRAULIC WORKOVER RIG AND SIMULATION FOR LOWERING PIPESTRING

0 INTRODUCTIONThe workover rig is often used in oilfields, and the ordinaryworkover rig has an unreasonably large energy waste. Thereforethe Shengli oilfield in China developed the energy-saving type ofhydraulic workover rig. This rig received the inventi…     

FORCE ANALYSIS CONSIDERING MANUFACTURE ERROR OF PIN-HOLE-OUTPUT MECHANISM IN CYCLOID DRIVE

Based on the analysis of the pin-hole-output mechanism in the cycloid drive , a more accurate force analysis method is provided, in which the manufacture error is considered, by which the contact force between pin and pin-hole can be calculated more accurately in the whole driving process.     

搅拌摩擦焊径向阻力的动态测量与分析

利用压力传感器对聚氯乙稀塑料搅拌摩擦焊时搅拌头受到的径向阻力进行动态测量,对引起搅拌头径向阻力变化的原因及相关因素的影响规律进行分析.结果表明,搅拌摩擦焊过程开始后,径向阻力要经过一个先急剧上升,达到峰值后又迅速下降,到某一定值后稳定下来的过程.在其他条件不变的前提下,仅提高搅拌头的旋转速度使径向峰值阻力和稳态阻力都下降,达到峰值和稳态阻力的时间都缩短;仅提高焊接速度使峰值阻力大幅度上升,而稳态阻力却有升有降,但幅度不大,达到峰值阻力的时间变化不大,而达到稳态阻力的时间延长;搅拌头直径的变化会同时引起摩擦发热功率和散热功率的变化,它对径向阻力的影响比较复杂.     

静压轴承自控系统动态品质的优化方法

提出带节流器的自适应性静压轴承系统动态品质的分析与优化方法,通过在系统内以不同方式引人类型各异的校正装置,可以改善轴承系统的动特性,提高主轴的回转精度。利用自控系统稳定性理论,对优化前后系统的过渡过程曲线和对数相频、幅频特性图像进行综合分析和对比,评定不同方法对轴承系统动特性改善的效果,并且对它们的应用范围作了说明,为改善主轴系统动态品质及其优化设计提供理论依据。     

动态模拟试验技术在汽车结构动强度分析中的应用

远程参数控制技术日益成为汽车台架模拟试验不可缺少的技术手段。以轿车车身为研究对象，利用远程参数控制技术实现了在实验室内对实际道路行驶状况的复现，并且对两种载荷作用下的试验数据数据进行分析对比，由此对汽车结构动强度模拟试验技术进行了研究和探索。     

主动控制空气支承动态特性的研究与优化

基于现代控制理论,提出了一种新型的主动型空气支承,不改变供气压力,利用压电陶瓷（PZT）的伸缩量来补偿空气膜厚度随外部干扰的变化对支承精度的影响。在建立理论模型的基础上,介绍了二维自由度控制器的优化设计方法,使系统具有精度高、响应速度快和抗干扰能力强的特点,并对主动空气支承系统的动态特性进行了分析研究,为主动空气支承的应用提供了理论依据。     

SIMULATION OF FLUID FLOW IN CHANNEL OF A NOVEL HYDRAULIC SHOCK GENERATOR

0INTRODUCTIONA novel hydraulic shock generator (SHG) based on the principle of water hammers has been recently developed. The experimental investigation［1］ shows that SHG could generate intense periodic shocks demanded by several construction machines. However the engineering applications of SHG are limited by its life span. For the further improvement of its capability, the flow patterns inside its complex passages have been investigated.The flow visualizations in the complex geome…     

动力学边界模拟中的振型修正与模态截断

对于航空复杂试件,通过柔性夹具动力学优化设计,模拟真实结构以为试件提供给试件的动力学边界,是亟待解决的问题。文中对振动试验中位移响应进行分析,强调指出,模拟结构真实动力学特性,要求试验试件与原试件的固频及振型一致。固频模拟较易实现,振型模拟则否,故文中主要关注振型模拟。对模态截断和振型修正这两个重要问题进行研究,给出以能量范数表示的模态截断判别函数,以及基于线性空间变换的振型修正方法。     

高架桥式高速五坐标龙门加工中心动态仿真与结构优化

在大型高架桥式、高速、高精度五坐标龙门加工中心的动态设计中,通过动态测试的方法获得导轨结合面的特性参数,并将其应用到数字仿真模型中,提高模型的精度。在结构动态分析中采用刚体与柔性体结合的仿真方法,对加工中心的关键部件进行柔性化,分析其对系统相应的影响,并在此基础上对这些主要部件进行结构优化设计,提高系统的动态特性。     

DYNAMIC MODEL AND SIMULATION OF A NOVEL ELECTRO-HYDRAULIC FULLY VARIABLE VALVE SYSTEM FOR FOUR-STROKE AUTOMOTIVE ENGINES

In modern four-stroke engine technology, variable valve timing and lift control offers potential benefits for making a high-performance engine. A novel electro-hydraulic fully variable valve train for four-stroke automotive engines is introduced. The construction of the nonlinear mathematic model of the valve train system and its dynamic analysis are also presented. Experimental and simulation results show that the novel electro-hydraulic valve train can achieve fully variable valve timing and lift control. Consequently the engine performance on different loads and speeds will be significantly increased. The technology also permits the elimination of the traditional throttle valve in the gasoline engines and increases engine design flexibility.