Dynamic analysis of rotating flexible disk subjected to double slider loading systems

Rotating disk subjected to stationary slider loading system is a very common mechanical structure. This paper investigates the multibody dynamics of a rotating flexible annular thin disk subjected to double slider loading systems. Along the rotating disk radial and circumferential directions, two stationary slider loading systems are distributed. System dynamic model is solved by Galerkin＇s method, and then natural frequency, dynamic stability and mode shape are determined with a quadratic eigenvalue problem. Effects of the distributing positions and interaction mechanism of the double slider loading systems on natural frequency, dynamic stability and mode shape are discussed and investigated.

Experimental Study of the Motion Modes of a Planar Mechanical System with Multi-Clearance Revolute Joints

Clearances in joints of a mechanical multibody system can induce impulsive forces, leading to vibrations that compromise the system’s reliability, stability, and lifespan. Through dynamic analysis, designers can investigate the effects of the clearances on the dynamics of the multibody system. A revolute joint with clearance exhibits three motions which are;free-flight, impact and continuous contact motion modes. Therefore, a multibody system with n-number of revolute clearance joints will exhibit 3n motion modes which are a combination of the three motions in each joint. This study investigates experimentally the nine motion modes in a mechanical system with two revolute clearance joints. A slider crank mechanism has been used as the demonstrative example. We observed that the experimental curve exhibits a greater impact compared to the simulation curve. In conclusion, this experimental investigation offers valuable insights into the dynamics of planar mechanical systems with multiple clearance revolute joints. Utilizing a slider-crank mechanism for data acquisition, the study successfully confirmed seven out of nine motion modes previously identified in numerical research. The missing modes are attributed to inherent complexities in real-world systems, such as journal-bearing misalignment.

Configuration Optimization of Two-Rail Sliders on Dynamic Characteristic

An optimal design methodology for the configuration of two rail slider was proposed to get better dynamic performance. The taper length, taper height and the rail width of the reading/writing head are considered as design variables. The complex geometry method is utilized as the search scheme in the optimization process. Optimization results show that the new slider has better dynamic characteristics and is more stable than the original designed slider. The optimization process also demonstrates that the optimum model and optimum method is effective.

HACCP体系在虾滑生产中的应用

应用危害分析及关键控制点(Hazard Analysis and Critical Control Point,HACCP)体系的基本原理,结合虾滑的实际生产工艺,对生产过程中可能存在生物的、化学的、物理的危害进行分析和评估,最终确定原辅料验收、调味、金属探测3个关键控制点,并制定相应的预防和控制措施,体系的运用可以有效、全面、系统地监控虾滑产品的质量,确保食品安全。

塑料外壳注射模设计

按照塑件结构设计了1副两板注射模,为了降低模具制造成本,将定模板适当增厚,省去定模座板,为了减少塑件表面的流痕和方便修剪浇口凝料,将塑件上浇口对应的位置设计成凹形。针对塑件侧面的扣位结构,采用由斜导柱驱动的侧滑块机构脱模,对模具两侧的滑块设置减速弹簧,降低滑块在合模时的速度,以减少滑块对模具零件的撞击。斜推杆与安装座之间通过圆弧形扣位相连,简化了模具结构,根据塑件结构,采用推管与推杆相结合的推出方式脱模,并根据模具结构设置“直通+隔片式水井”相结合的多个冷却回路的随形冷却系统。

超大型钢桁梁步履式顶推+滑块滑移施工受力分析

西安地铁10号线渭河特大桥主桥为主跨300 m的曲线上加劲连续钢桁梁桥,采用公轨合建,双层桥面布置,上部结构采用超大型钢桁梁与曲线加劲弦组合结构。主桥施工时先架设钢桁梁,再施工刚性加劲弦。钢桁梁采用步履式顶推+滑块滑移施工,顶推采用南、北双向同步施工。为保证顶推施工过程中主体结构及临时支撑结构的受力安全,采用MIDAS Gen软件建立主桥有限元模型,采用生死单元法进行施工全过程分析,对钢桁梁承载力、支座反力、合龙阶段落梁变形调整值、合龙阶段温度效应影响、顶推过程中不同步的影响以及瞬时阵风作用下顶推体系承载力进行分析验算。结果表明:钢桁梁的承载力及瞬时阵风作用下顶推体系承载力均满足规范要求;钢桁梁顶推时墩顶最大支座反力取值24000 kN;南侧W05墩与北侧L08临时墩落梁变形调整值分别取-60 mm和-40 mm,以消除合龙口端部下挠变形;以环境温度20℃为参考值,整体升温不超过10℃和上、下弦温度梯度为10℃以内时对合龙影响不大;顶推过程中横、纵向瞬时不同步位移建议分别控制在5 mm和20 mm以内。

可换镶件多功能教学注射模设计

随着汽车工业的快速发展,现在国内模具领域技术人才短缺的局面,各个企业、职业院校都在不断的研究模具技术人才的培养模式,以加快模具人才的输出,解决模具技能人才供应不足的难题。本副可换镶件多功能教学模具是基于德国双元制模具制造专业企业学徒和学生而量身定制设计的,针对各大模具制造企业和各高校模具制造与设计专业没有合适的教学模具,结合模具人才的培养目标出发,设计出了本副可换镶件多功能教学注射模,包含了两板注射模的经典结构、材料、CNC加工的全流程工序,巧妙的加入了实用性和趣味性的产品结构设计,体现和涵盖了注射模的核心结构,通过本副模具的设计和推广,为企业和职业院校模具制造与设计专业学生提供专业实训教具参考和学习。

Influence of wall slip on the hydrodynamic behavior of a two-dimensional slider bearing

In the present paper, a multi-linearity method is used to address the nonlinear slip control equation for the hydrodynamic analysis of a two-dimensional （2-D） slip gap flow. Numerical analysis of a finite length slider bearing with wall slip shows that the surface limiting shear stress exerts complicated influences on the hydrodynamic behavior of the gap flow. If the slip occurs at either the stationary surface or the moving surface （especially at the stationary surface）, there is a transition point in the initial limiting shear stress for the proportional coefficient to affect the hydrodynamic load support in two opposite ways： it increases the hydrodynamic load support at higher initial limiting shear stresses, but decreases the hydrodynamic load support at lower initial limiting shear stresses. If the slip occurs at the moving surface only, no fluid pressure is generated in the case of null initial limiting shear stress. If the slip occurs at both the surfaces with the same slip property, the hydrodynamic load support goes off after a critical sliding speed is reached. A small initial limiting shear stress and a small proportionality coefficient always give rise to a low friction drag.

双滑块液压机钛合金高温换模生产线

介绍了THP56-500A双滑块液压机钛合金高温换模生产线。该生产线由双滑块液压机、模具回收台、模具初装台、保温炉、预热炉和高温模具搬运系统等组成。该生产线避免了人工换模热辐射的影响,提高了制件生产效率,大大节省了生产成本。

INVESTIGATIONS OF THE INFLUENCE OF TAPER CONTAMINATION ON THE FLYING CHARACTERISTICS OF A SLIDER

The influence of taper contamination on the static and dynamic characteristics of a slider is studiedin detail. Two models of taper contamination, including the effect of skew angle and the number of the railwith taper contamination as well as the amount of contaminator on the taper,are investigated respectively. Anequivalent scheme is applied to evaluate the frequency responses with different flying attitudes in three de-grees of freedom. Ca1culations show that whether model is considered and how many tapers are contaminated,the static and dynamic characteristics of the slider change little in a very large contamination scale,but oncethe amount of contaminator exceeds some limit,the flying attitude of the slider is degraded catastrophically,which is easy to cause the slider crash. The skew angle,when it is large enough,may ameliorate or deterioratethe flying characteristics of the slider depending on the slider attitude when the transverse air flow passesthrough it.

Analysis and Optimization of Passenger Side Knee Slider Compression in Front Impact

The influences of different design factors,as well as dummy posture,on an occupants' knee slider compression,were studied in this paper.Based on the vehicle geometry data,the simulation model,including both the multi-rigid-body and finite element(FE)part,was built up and validated with China New Car Assessment Program(C-NCAP)full impact to ensure the accuracy of the model.By adjusting the design parameters and the posture of the femur and lower leg,different factors affecting the passengers' knee slider compression were evaluated,with the help of MAthematical DYnamic MOdel(MADYMO)simulations.The study indicated that the leg posture,the stiffness of the IP and angles of the carpet have significant effects on the knee slider compression in this case.By decreasing the angle between the femur and lower leg from 133° to 124°,the maximum knee slider compression was decreased by 17.3% and by scaling the IP stiffness from 1 to 0.7,it could be decreased by 18.6%.Also,decreasing the angles of the carpet from 28° to 37°can help reduce the knee slider compression by 18.3%.

Integral Transform Method for a Porous Slider with Magnetic Field and Velocity Slip

Current research is about the injection of a viscous fluid in the presence of a transverse uniform magnetic field to reduce the sliding drag.There is a slip-on both the slider and the ground in the two cases,for example,a long porous slider and a circular porous slider.By utilizing similarity transformation Navier-Stokes equations are converted into coupled equations which are tackled by Integral Transform Method.Solutions are obtained for different values of Reynolds numbers,velocity slip,and magnetic field.We found that surface slip and Reynolds number has a substantial influence on the lift and drag of long and circular sliders,whereas the magnetic effect is also noticeable.

Unified gas-kinetic simulation of slider air bearing

The unified gas-kinetic scheme （UGKS） is presented and used in this letter to study the slider air bearing problem. The UGKS solutions are first val- idated by comparison with direct simulation Monte Carlo results. After valida- tion, the UGKS is used to study the air-bearing problem under different non- equilibrium conditions. On the surface of the slider, the dependency of the gas pressure and normal force on the Mach and Knudsen numbers are fully evaluated. The non-equilibrium effect on the force loading in the whole transition regime up to the free molecular limit is also studied.

美国教授Slider来华讲学

应石油天然气总公司开发部的邀请.美国俄亥荷州立大学化学工程系油藏工程学教授Slider 于一九九零年十月二十六日来华讲学。十月二十九日至十一日,Slder 先生在华北油田油气井测试公司讲授油藏工程学。讲授的主要内容是油藏工程学的基本知识,即达西方程,油藏流体的稳定态流动,不稳定态流动和假稳定态流动,以及适用于这些流动状况的方程及这些方程的应用。

Design and Modeling of Femto Air Bearing Slider

This paper presents the studies of the performance of an improved femto air bearing slider which is optimized based on the past studies and effort. The flying characteristics performance of this novel femto slider is relatively stable over different radii. This optimized slider achieved a flying height of 3 nm, with variation of about 0.2 nm. The variations for pitch and roll values are 6 μrad and 0.9 μrad respectively. In the studies for the effect of side rail on flying characteristics, it was found that there exists transition of pitch value when the side rail is located very close to the leading edge. The modulation of flying height reduces greatly when the areas of double shallow steps increase. The roll variation reduces when the flat double shallow steps profile is modified into a “V-Shape” profile.

Dynamic Simulation of a Smart Crank and Slider Mechanism

In this paper, a smart crank and slider mechanism is analyzed mostly from a dynamic view. By means of dynamic explicit finite element method, 3D nonlinear structure is simulated. It is proved that the mechanism can effectively accomplish smart movement prescribed. And in order to ensure reciprocal movement with higher frequency, measures should be taken to avoid over heating of parts. Compared with internal energy, kinetic energy of total rigid body is dominating, and Ydirection equivalent rigid velocity is much higher than X direction velocity. Equivalent rigid velocity of all parts is consistent with respective movement condition. For both energy and velocity, slider effect is dominating. Three direction equivalent inertia force oscillates. Force amplitude in Y-direction is comparitively the greatest.

在VC++工具栏中添加Slider控件实现视图实时缩放

用Slider控件的滑动来实时控制视图平滑地缩放,利用控件的范围控制缩放大小.程序通过VC++的消息反射机制,添加必要的消息映射函数,实现用Slider控件控制图形显示区的目的.结合VC++平台,用Sli-der控件能方便地实现控制视图缩放,也比单纯放大缩小视图要直观连续,更适合用户的需要.同时,利用同样的思想,也可以很方便地实现其他界面上的改进.

盖销扣注射模设计

根据汽车座椅系列-盖销扣塑料模具的结构特点和生产要求,提出了较为详细的塑料模具工艺方案:塑件的特征工艺分析、结构设计、工作原理,并对具有销扣特点的塑件大角度斜顶机构注射模结构中的关键技术进行了分析,并且完成了塑料模具工艺部件的设计和应用。确定了销扣塑件斜顶机构抽芯模具的冷却机构、浇注系统、斜顶抽芯机构和顶出系统的结构,重点研究了大角度斜顶机构和点浇口形式等较为复杂的开合模过程,实现了模具结构的整体设计。结果表明,模具整体结构紧凑、工作稳定,成型件缺陷少,符合生产过程中的要求。同时也为加工企业缩短模具生产周期,降低生产成本提供了参考。

基于UG和Anycasting的铝合金电机壳压铸模设计

介绍了电机壳的结构特点,在铸件毛坯上增加过桥结构,以增强压铸过程中铸件的稳定性,利用Anycasting模流软件分析了充型和凝固过程并优化了模具结构,在滑块结构上设计了反推结构,保证成型铸件的薄弱区域在滑块脱模过程中的尺寸精度。

基于慧正平台的压铸模滑块系统自动化设计研究

为了解决压铸模设计过程中滑块系统设计过程复杂的问题,提出了基于慧正平台的压铸模滑块系统自动化设计方法,该方法结合NX自身建模规则和慧正系统重用驱动,设计了层次化关联模型,并研究了关联模型的数据继承机制与数据更新机制,实现了滑块系统在设计过程中的重用和有序更新。结合NX平台上的慧正模具辅助设计系统,应用自定义部件模型及参数,提升了滑块系统设计效率,缩短了模具开发周期。