Residual stress measurement in an extra thick multi-pass weld using initial stress integrated inherent strain method

Residual stresses existing in a multi-pass butt joint with a thickness of 70 mm, using a flux-cored arc welding process, were measured by an inherent strain method (ISM). Since such a thick plate before welding contains a large amount of initial residual stresses (−300 to +100 MPa), the initial stresses were integrated with conventional ISM in order to determine the total residual stresses in a welded joint. Two methods named as initial stress integrated ISM and initial inherent strain integrated ISM were suggested for the consideration of the initial stress distributions through the thickness of base plates. The results show that there is a significant difference between the integrated ISM with initial stresses or initial inherent strain and the conventional ISM without initial stresses. The residual stresses measured by any of the initial stress integrated ISM and initial inherent strain integrated ISM agreed well with the neutron diffraction measurement. Thus, the proposed initial stress integrated ISM is a proper destructive measurement method in the case of thick weld joints.     

燃油喷雾PIV测试方法研究

本文使用美国TSI公司的PIV(ParticleImageVelocimetry)设备,对电控高压共轨燃油喷射系统在3个不同的喷射压力(80MPa,100MPa,110MPa)下的燃油喷雾进行了测试,获得了喷雾图像,并对喷雾测试过程中的各种参数设置以及一些问题做了详细分析。     

Air Cored Rogowski Coil for Measurement of Partial Discharges

A Rogowski coil was designed to measure partial discharge (PD) signal with low currents and high frequency. The possibilities of obtaining better measurements of PDs were explored by changing the inductance, mutual inductance, resistance, and capacitance of the coil. The designed Rogowski coil was calibrated under square wave voltage and arbitrary sine wave voltage. Then, according to the parameters of the Rogowski coil, the effect of changing some of these variables was simulated using a bode plot. Compari...     

CORS技术与全站仪在郁江跨江线缆测量中的应用

跨江线缆测量主要采集跨江线缆的空间位置和属性特征,具有测区范围大、跨越地域广、测程较远等特点。文章结合广西郁江南宁至贵港Ⅱ级航道的跨江线缆测量工程实际,介绍采用CORS技术结合全站仪进行跨江线缆外业测量的技术方法,并分析了该方法与传统作业方式相比所具有的的优势,为CORS技术与全站仪的联合测量应用提供参考。     

控制测量的误差分析与处理

以目前广泛应用于施工的测量仪器全站仪为例进行控制测量的误差分析与处理.     

内燃机车油耗计量及分析系统的研究与实现

通过机车燃油消耗现状的分析,研究内燃机车油耗计量及分析系统的实现方法.     

锚杆长度和注浆饱满度检测评判方法的研究

通过对锚杆试验模型进行应力波检测,结合希尔伯特时频分析方法,建立锚杆长度和注浆饱满度评判方法,为应用无损检测技术快速检测锚杆质量提供依据,对锚杆质量检测具有一定的推广价值。     

机械式变速箱传动效率实验研究分析

传动效率是机汽车变速箱传动效率是直接反映变速箱设计、制造水平的一项重要参数。文章对汽车变速箱传动效率测量影响因素、测试方法、及数据处理方面进行探讨,并结合实际测试工作中的经验总结了一些实际应用方法及对此参数的影响因素,藉此对机械式变速器效率测量精度提高方面起到参考及指导作用。     

接触网几何参数测量仪检定台架的可靠性评估

介绍针对DJ J-8激光接触网检测仪的接触网几何参数测量仪检定台架的结构以及测量模拟接触线高度、拉出值、支柱侧面限界、轨距和水平（超高）等关键参数的测量方法.并依据JJF 1059-1999《测量不确定度评定与表示》开展检定台架接触线高度、拉出值、支柱侧面限界、轨距和水平等关键测量项目的测量不确定度评定,结果表明,该检定台架满足Ⅰ级精度的接触网几何参数测量仪的检定要求.     

便携式汽车运动参数综合测试系统研究

以捷联式惯性导航原理为基础，研究短时惯性测量系统在汽车道路试验中的应用，提出了便携式汽车运动参数综合测试系统的方法，对系统配置，测试原理，计算方法，软件流程，惯性元件选择等重要问题进行了分析与讨论，并给出了计算机仿真结果。