A new technique for the investigation of stick-slip

The stick-slip phenomenon has been investigated using an existing high frequency friction machine at very low speed. Static friction was found to vary with frequency and to approach a maximum as the length of time during which the contacting surfaces were at rest increased. This was thought to be due to a squeeze film effect leading to increasing asperity contact.     

Laboratory evaluation of anti‐fretting lubricants

To characterise the friction and wear behaviour of materials and lubricants under a variety of operating conditions, laboratory models are frequently used to provide useful information. For example, during the development and/or selection of tribomaterials and lubricants, laboratory ranking of candidate products can save many hours of field testing. A reciprocating ball‐on‐flat wear test rig has been developed to rank the performance of materials, surface coatings, and lubricants under boundary, extreme‐pressure, or fretting conditions in a variety of environments and at various temperatures. The rig design is based on ASTM G133–1995. The friction force and wear are measured on both specimens while the load, stroke length and frequency, test temperature, lubricant type, test duration, surface topography of both ball and flat specimens, specimen materials, and environmental conditions are noted. The results presented in this paper refer specifically to a series of tests performed to evaluate various anti‐fretting lubricants. Two lubricants are compared in terms of friction coefficient and wear volume over time. A clear difference is shown between the two products.     

Piezoelectric inertial robot for operating in small pipelines based on stick-slip mechanism: modeling and experiment

Small pipes exist in industrial and biomedical fields, and require microrobots with high operational precision and large load capacity to inspect or perform functional tasks. A piezoelectric inertial pipeline robot using a “stick-slip” mechanism was proposed to address this requirement. In this study, the driving principle of the proposed robot was analyzed, and the strategy of the design scheme was presented. A dynamics model of the stick-slip system was established by combining the dynamics model of the driving foot system and the LuGre friction model, and the simulation analysis of the effect of system parameters on the operating trajectory was performed. An experimental system was established to examine the output characteristics of the proposed robot. Experimental results show that the proposed pipeline robot with inertial stick-slip mechanism has a great load capacity of carrying 4.6 times (70 g) its own mass and high positioning accuracy. The speed of the pipeline robot can reach up to 3.5 mm/s (3 mm/s) in the forward (backward) direction, with a minimum step distance of 4 μm. Its potential application for fine operation in the pipe is exhibited by a demonstration of contactless transport.     

非重复充装瓶阀技术要求和型式试验标准分析

对非重复充装瓶阀的技术要求和型式试验采用的国家标准（GB）和欧洲标准（EN）进行了比较分析。     

Penn State润滑油微氧化试验方法的研究进展

ＰｅｎｎＳｔａｔｅ润滑油微氧化试验方法是一种非常有效简便的实验室评价方法,其具有油样量少,评价时间短,可半定量分析氧化产物及其组成,并减少了氧的扩散限制等优点,因此。该方法自问世以来得到了很大的发展,国外一些润滑公司已半该方法作为评价润滑油氧化行为的手段之一。ＰｅｎｎＳｔａｔｅ润滑油微氧化试验装置配备有凝胶色谱（ＧＰＣ）和粘土吸附柱技术。该装置能够模拟发动机活塞环区域的高温薄膜条件,ＰｅｎｎＳｔａ     

自动化测试在软件黑盒测试中的应用

介绍了黑盒测试的方法,研究了手工测试的缺陷,提出了自动化测试方法在黑盒测试中的应用.给出了两个典型实例,并进行了测试问题的分析和核心脚本的编写.通过对典型实例的总结,分析了在黑盒测试中应用自动化测试技术的优势.在大型软件测试中,该方法的优势更为明显.     

检具随机误差的验收评定方法

介绍了四种常用的检具随机误差验收评定方法,并分析了各种评定方法的特点及适用性。     

汽车空调用热力膨胀阀性能测试系统的研制

热力膨胀阀是汽车空调的重要部件,其性能对汽车空调的制冷效果、运行寿命有着重要影响。针对汽车空调用热力膨胀阀的关键性能现有测试方法的不足以及性能测试系统的缺失,对过热度、阀口泄漏和耐久性能的测试方法进行了研究,提出了过热度流量测试法和阀口泄漏差压测试法,并对耐久性能测试的时间参数进行了优化。在此基础上采用PLC控制技术研制了一套热力膨胀阀性能测试系统,并利用图形化编程语言VB开发了测试系统控制软件。研究结果表明,该系统能按照标准要求自动完成热力膨胀阀过热度、阀口泄漏和耐久性能的测试。所研究的热力膨胀阀关键性能检测方法能够满足热力膨胀阀主要性能指标的测试要求,所设计的测试系统提高了热力膨胀阀性能测试的精度,提升了检测效率及自动化水平。     

钢管水压试验机系统的研究与分析

钢管水压试验机主要用于钢管的耐压试验,是确定所生产钢管是否达标及研究钢管耐压性能的重要设备。对钢管水压试验机系统进行了分类,介绍了钢管水压试验机系统设计的主要原则,列举了国内钢管水压试验机系统设计制造使用的情况,分析了提高系统工作效率的方法,提出了钢管水压试验机系统设计的发展趋势。     

振动环境试验设备与技术的现状及进展

综述了国内外振动环境试验设备及技术的现状,简要分析了我国振动试验水平与国外产生较大差距的原因,指出了振动环境试验存在的问题,说明了振动环境试验设备及技术发展方向。     

阀门启闭扭矩连续测试装置的试验与研究

介绍了阀门启闭扭矩连续测试装置的性能特点、技术参数基及其控制方式。给出了装置通过扭矩传感器测试阀门的力矩变化并将模拟数据转换成数字信号由计算机控制输出的工作过程（该装置专利申请号：200620149672X）。     

液压万能材料试验机测控系统研究

为解决材料试验机测控系统功能单一、扩展试验复杂等问题,将基于Delphi语言的软件技术与基于单片机的自动控制技术结合应用到万能材料试验机的控制系统中。开展了针对通用材料拉伸、压缩等试验标准的分析,建立了万能试验机测控系统软、硬件与试验标准规程之间的关系,提出了模块化的上、下位机软件及硬件的设计方法;在建立测控系统上位机软件及下位机软、硬件平台的基础上,对提出的模块化实验设计方法进行了评价,并进行了多目标持荷试验、水泥胶砂抗压试验以及金属拉伸试验。研究结果表明,基于Delphi与单片机的上、下位机模块化试验系统方案能够满足各种材料试验标准需求,具有试验规程编制简单灵活的特点,解决了万能材料试验机功能单一、试验扩展复杂的缺点。     

测量能力指数C_g的本质及其实际应用

对评定检测器具的重要指标———测量能力指数Cg 的本质进行了阐述和分析 ,并结合实例介绍了其应用。     

碟式分离机转鼓应力的无线测试与仿真对比研究

针对碟式分离机转鼓在运行情况下应力测试难的问题,在碟式分离机转鼓试验台上,对两种不同的结构(单个转鼓和转鼓组件)开展了无线动态应力测试,并结合有限元仿真进行了对比研究。采用Wi Fi无线通讯技术进行电阻应变测试实验,直接获得不同位置不同转速下的转鼓内壁应力应变数据,并与行业标准JB/T 8051-2008《离心机转鼓强度计算规范》和有限元仿真分析得到的结果进行对比分析。研究结果表明,将有限元法的计算结果和实验数据进行了比较,两者基本吻合;空转鼓旋转时,转鼓组件鼓壁内的环向应力大于单个转鼓鼓壁内的环向应力,而且随着分离机转速的提高,两者相差越大;单个转鼓的应力情况跟规范基本吻合,说明直接使用规范中的公式会有一定偏差。     

核电装备制造中落锤试验的影响因素

落锤试验是核电装备制造中对材料进行检测和评判的一种重要方法.本文分析了试样尺寸、试样焊接、过程控制和结果判定四类影响落锤试验的因素,可在今后的试验过程中进行控制,使测试结果达到稳定准确.     

安全阀试验规定及其试验装置的分析与研究

通过研究ASME、ISO等国际标准对安全阀动作性能试验和排量试验的内容和方法,阐述了建立安全阀试验台基本的相匹配参数和必要性。     

Comparison of threshold galling results from two testing methods

In this investigation, threshold galling tests were performed on several types of stainless steel using area contact and line contact testing procedures. The area contact test method employed was the ASTM standard G98, button-on-block test. In this test method, the end of a cylindrical button is placed in contact with a flat block at a desired contact pressure. The button specimen is rotated through one revolution and both specimens are visually inspected for the presence of galling. The line contact test method used was the button-on-cylinder test where the end of a stationary button contacts a cylinder along its length. After a given load is applied, the cylinder is rotated for a fixed number of cycles and the wear surfaces are inspected for galling. A comparison of the threshold galling results from each of the test methods is discussed in this report. Various testing conditions that influence the onset of galling are discussed, including sliding distance, surface oxide layer thickness, and stress distribution as well as the impact of the interpretation of experimental data on reported galling threshold magnitudes.     

应用于钢轨检测的便携式涡流探伤仪的研制

钢轨损伤是影响铁路运输安全的主要因素,国内主要依靠巡道工人的日常检测,但现在还没有一种针对巡道工人使用的设备。研究设计了一种灵敏度高、便于携带且经济的仪器。基于涡流探伤的基本原理,采用正交试验方法设计、制作了一种精细的涡流传感器,用于提取微弱的裂纹信号,再由后台放大器放大,经过处理后在显示器上显示裂纹缺陷的相对大小,最后蜂鸣器报警,实现了防患于未然的目的。     

微型涡轮的旋转盘腔内流场二维与三维数值模拟的比较

用FLUENT软件对带有微型涡轮的旋转盘腔内部流场进行了二维和三维的数值模拟。在数值计算中应用标准K—epsilon双方程湍流模型，通过计算研究发现：二维和三维数值计算在低旋转雷诺数时趋于一致，随着旋转雷诺数增加三维效应增强计算结果差距增大。研究结果显示：涡轮内部螺栓和微型涡轮的不同处理方式是导致二者数值模拟差异的主要原因。     

给排水系统用阀门的检验和试验

介绍了给排水系统用阀门制造和检验中常用的相关标准，论述了不同类型阀门应进行的检验项目和试验方法。