Failure of a Fusion Welded Ball Joint as a Result of Modification in MnS Direction

A failure investigation was performed on a ball joint from an ATV front suspension system. The location of the fracture was the bearing ball/stud interface, which is a fusion-welded joint, and occurred after approximately 20 h of field-testing. The two parts are made out of carbon steel and were previously heat-treated. Many elongated MnS inclusions were found in the stud material, and these inclusions were parallel to the symmetry axis. Even though these inclusions were not significantly sized, their number was important. Macroscopic evidence showed that the joint failed in a ductile mode under centered tensile overload. Microscopic examination showed that MnS orientation changed in the fusion joint area. The inclusions had been redirected during the welding process and laid parallel to the fracture surface. This reorientation caused a significant decrease in the effective cross section of the joint and overload fracture occurred.     

齿形节理渐进破坏直剪试验研究

通过对由两个齿形凸体组合构成的双齿节理进行直剪试验,分析了两个齿形凸体的起伏角相等时和不等时双齿节理的剪切特性;观察和分析含两种不同起伏角凸起体的双齿节理的渐进破坏过程与机理,以及两个齿形凸起体的排列顺序对此类双齿节理的剪切强度和变形特性的影响.     

中板轧机主传动万向接轴辊端接头断裂事故分析

采用机械测试、三维有限单元、金相组织分析等现代综合分析技术 ,对中板轧机主传动万向接轴辊端接头断裂事故进行分析。事故的主要原因是热处理工艺不当     

汽车半轴摩擦焊接头焊后热处理工艺及强韧性能的控制

研究了ＳＸ１１０型汽车半轴摩擦焊接头的焊后热处理工艺对其强性能的控制作用，并对热处理规范参数进行了优化。台架试验结果表明：用锻造－摩擦焊接复合工艺生产的ＳＸ１１０型汽车半轴摩擦焊接头的强韧化水平达到和超过了整体锻造半轴的强韧化水平。     

整体式桥台无缝桥梁技术

整体式桥台无缝桥梁是将桥梁的上部结构与桥台结为整体,避免了伸缩缝桥梁常见的水侵蚀和冻害。分析了桥梁伸缩缝装置存在的问题;介绍了国内外无伸缩缝桥梁的工程实践;提出了整体式桥台无缝桥梁应用中存在的问题。     

A study of manipulator with passive revolute joint

In this article, equations of motion of a manipulator, whose mechanism has a passive revolute joint, are derived in consideration of the characteristics of driving source. Considering the fi nal condition of displacement and velocity of the passive joint, trajectories of velocity for energy saving are calculated by iterative dynamic programming. And the dynamic characteristics of manipulator control based on the trajectory for energy saving are analyzed theoretically and investigated experimentally. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

绝热橡胶蛇腹接头制作技术研究

介绍一种以水镁石纤维/NBR橡胶料片模压成型耐烧蚀性蛇腹接头之制作技术。研究结果显示,橡胶料片之排料方式为影响制作品质的关键性因素。耐烧蚀性蛇腹接头可应用于国防产业领域,例如固体火箭推进器之推力控制组件,而本技术亦可配合产业实际需求,衍生推广应用于一般民生工业领域。     

乌金峡水电站伸缩节漏水处理对策

乌金峡水电站4台机组运行时,均出现伸缩节漏水现象,经过处理,漏水问题得到解决。对漏水原因及采用的处理措施进行总结分析。     

小湾水电站拱坝横缝接缝灌浆施工技术

小湾水电站大坝横缝接缝灌浆施工前,进行了室内及现场浆液性能试验,为施工提供了方案和依据,采用0.45∶1水灰比浆液对小湾水电站横缝进行接缝灌浆,取得了很好的效果。     

Three-Dimensional Stress Analysis of Adhesive Butt Joints of Solid Cylinders Subjected to External Tensile Loads

This paper deals with a three-dimensional stress analysis of adhesive butt joints of similar solid cylinders subjected to external tensile loads. Similar adherends and an adhesive bond are replaced with finite solid cylinders in the analysis. Stress distributions on adhesive joints are analyzed strictly by using the three-dimensional theory of elasticity. The effects of stiffness, thickness and Poisson's ratio of the adhesive bonds and of external load distribution on the normal and the shear stress distributions are shown by numerical calculations. In addition, the analytical result is compared with the result obtained by F.E.M. It is seen that they are in fairly good agreement.