Effect of surface roughness on the static characteristics of inclined plane slider bearing: Rabinowitsch fluid model

In this paper, a theoretical study of the effect of surface roughness on the static characteristics of inclined plane slider-bearing lubricated with Rabinowitsch fluid is analysed. Christensen’s stochastic theory for the lubrication of rough surfaces has been used for the derivation of generalised stochastic Reynolds-type equation. The two types of one-dimensional roughness patterns (Longitudinal and Transverse) are considered. Expressions for pressure, load carrying capacity, frictional force and coefficient of friction are obtained. It is found that the presence of transverse roughness pattern on the bearing surface increases pressure and load carrying capacity. Results are well agreement with smooth case.     

电流变液在工程中的应用

电流变液是一种在电场下暧时从液态变为类固态的智能材料。由于它能在瞬时改变材料的力学性能，增加了其表观粘度和强度，又具有可逆性，因而在工业上极具应用前景。本文主要论述了国内外电流变液研究在工程中的应用前景和发展趋向。     

用FANUC系统Cs轮廓控制功能实现五面加工的主轴定位

采用FANUC系统Cs轮廓控制功能实现主轴五面加工的定位,论述了实现这种控制方式的步骤、参数设置及应用程序的开发.     

Application of the ultrasonic propagation imaging system to an immersed metallic structure with a crack under a randomly oscillating water surface

Ultrasound is widely used and studied to satisfy the increased demands of the Non-destructive evaluation (NDE) and testing of underwater structures. However, because of the large size and mass of underwater structures, such as submarines, ship hulls, or nuclear reactor pipe lines, it is difficult to inspect the structures during operation. This underwater NDE technology is challenging but could be highly beneficial because the time and cost of maintenance will be effectively reduced. We propose an NDE method for immersed structures using an ultrasonic propagation imaging system with a piezoelectric sensor. The underwater sensing capability of a piezoelectric sensor is experimentally demonstrated using an aluminum plate specimen. A piezoelectric sensor can compensate for the decreased signal amplitudes due to leaky waves that are generated on interfaces between structures and water, since water transmits signals better than air. Additionally, a piezoelectric sensor can be applied even if the water surface is oscillating. Using these properties, the laser induced guided Ultrasonic propagation imager (UPI) inspected a T-shaped steel structure with a 2-mm crack on the weld zone. The inspection was implemented in three cases: a specimen without water, a specimen immersed in water and a specimen immersed in water with a randomly oscillating surface. The crack was visualized and measured using the ultrasonic wave propagation imaging algorithm, the adjacent wave subtraction algorithm, and the variable time window amplitude mapping algorithm. In the case with a randomly oscillating water surface, the laser pulse was refracted randomly based on Snell’s law. This phenomenon may cause degradation of the inspecting results. However, a repeated scanning process and outlier elimination led to an improved signal-to-noise ratio such that it was able to detect the crack. These results demonstrate the possibility to apply the laser UPI to submerged structures even if the water surface is randomly oscillating.     

含裂纹结构的极限载荷分析

将塑性极限分析应用于含裂纹结构极限承载能力的确定中 ,结合含裂纹结构达到的塑性极限条件和裂纹失稳扩展条件 ,判断结构是否达到极限状态 ,进而求出含裂纹结构的极限载荷 ,本文给出了这一计算过程的有限元普遍格式 ,并编制了相应的有限元程序 ,计算和分析了若干典型含裂纹平板的极限载荷 ,所得结论对研究含裂纹结构的失效模式和剩余强度确定具有理论和工程参考价值     

Identification of a friction model—Application to the context of dry cutting of an AISI 1045 annealed steel with a TiN-coated carbide tool

The characterization of friction coefficients at the tool-chip-workpiece interface remains an issue. This paper aims to identify a friction model able to describe the friction coefficient at this interface during the dry cutting of an AISI1045 with TiN coated carbide tools. A new tribometer has been designed in order to reach relevant values of pressures and sliding velocities. This set-up is based on a modified pin-on-ring system. Additionally a numerical model simulating the frictional test has been associated in order to quantify average friction coefficients around the spherical pin, from the standard macroscopic data provided by the experimental system. A range of cutting speeds has been investigated. It has been shown that the friction coefficient is very much dependant on the sliding velocity. A new friction model has been identified based on the average local sliding velocity.     

带远程站的PLC在电厂输煤系统中的应用

本文介绍了可编程序控制器在电厂皮带输煤控制系统中的应用，详细说明了远程Ｉ／Ｏ控制系统的特点和功能。