一等环规测量仪的研制

一等环规测量仪是将激光干涉仪测长技术、静态光电显微镜瞄准技术和精密微位移定位技术作为主体测量技术，以上三项技术的有机结合使该仪器的测量不确定度达到了国际法制计量组织(OIML)规定的一等环规的测量要求。     

陀螺转子静平衡测量方法的研究

介绍了一种新的陀螺转子静平衡仪结构设计,采用玛瑙刀口支承感应机构与光电自准直测角相结合的方法,实现对陀螺转子静不平衡量的测量。提出了新型粗、精双测刀机构实现高精度、大量程测量,减少刀口磨损,提高测量效率。通过转子托架摆动周期测量法确定了仪器灵敏度系数的精确调整方法。采用标准砝码对仪器进行了精确标定。实验结果表明该仪器测量示值误差优于4 mg·mm,量程达到2000 mg·mm。     

计量仪器的远程量值传递与溯源技术探讨

传统的量值传递与溯源方式存在两个问题,一是必须离线方式进行,把工作用计量器具定期拆下来,送到相应技术机构,在规定的实验环境下进行检定或校准,影响正常生产进程,二是都属于静态或稳态测试过程,只能获得参比工作条件下仪器的基本误差,不能获得现场应用中的附加误差。仪器物联网技术的发展使人们看到解决这两个问题的希望,如果能够利用物联网技术建立起计量仪器的远程量值传递与溯源系统,则可得出仪表的附加误差,从根本上保证现场计量数据的准确可靠。该文调研国内外计量仪器领域远程量值传递与溯源技术的研究现状,归纳计量领域远程量值传递的3种实现途径,即传递标准表、标准表置于现场、传递量值法,比较这3种实现途径的难易程度,最后提出实现理想方式的计量仪器远程量值传递与溯源技术尚需要研究的领域及具体研究内容。     

汽车外廓尺寸测量仪量值溯源方法研究

汽车外廓尺寸测量仪基于先进的计算机实时立体视觉技术,集光学、电子、计算机等高科技于一体,实现全自动、可视化、网络化,而且具有自动控制检测过程,加强对车辆的监督管理。文章主要从监管及安全角度探讨其计量性能要求和量值溯源方法,作为福建省开展校准汽车外廓尺寸测量仪的技术依据。     

2-D sizing of sodium oxalate crystals by automated optical image analysis

A new automated static optical image analysis (SOIA) method was developed for characterising the shape of sodium oxalate crystals by separately measuring their length and width. The automated size analysis combines crystal image acquisitioning with a custom-developed numerical algorithm for morphological analysis of crystals. The automation of the two main measuring steps enables characterisation of a large number of crystals ensuring statistically meaningful results. As part of the numerical algorithm, a rectangularity-based morphological filter was implemented to eliminate overlapping crystals and crystal networks. The developed optical sizing technique has a low detection limit of 0.25 μm, which is close to the theoretical resolution of optical microscopy. It is demonstrated that the new automated SOIA sizing technique is very sensitive in identifying oxalate crystals of different shape. The measured crystal size distributions are compared to those obtained by an AccuSizer sizing instrument to confirm that they are consistent with the measurements obtained by a conventional crystal sizing instrument.     

Numerical implementation of imperfect interfaces

One approach to characterizing interfacial stiffness is to introduce imperfect interfaces that allow displacement discontinuities whose magnitudes depend on interfacial traction and on properties of the interface or interphase region. This work implemented such imperfect interfaces into both finite element analysis and the material point method. The finite element approach defined imperfect interface elements that are compatible with static, linear finite element analysis. The material point method interfaces extended prior contact methods to include interfaces with arbitrary traction-displacement laws. The numerical methods were validated by comparison to new or existing stress transfer models for composites with imperfect interfaces. Some possible experiments for measuring the imperfect interface parameters needed for modeling are discussed.     

The Planning of Measurements when Analysing the Linear Model of the Static Characteristic of a Measuring Instrument

A method of planning measurements when analysing a linear model of the static characteristic of a measuring instrument without using actual values of the measured quantities is described.     

Measurement of small time intervals by means of an attachment to an electric timer

Conclusions Ferromagnetic materials with a rectangular hysteresis loop can be used for designing a short time-interval measuring instrument and providing it, as compared with existing instruments, with high sensitivity, small over-all size and weight, a large measuring range and a simple circuit consisting of static elements which are insensitive to shaking and vibrating and do not depend on humidity and temperature.     

Measuring the conformity of non‐simplicial elements to an anisotropic metric field

This paper extends an approach for measuring the element conformity of simplices to non‐simplicial elements of any type, in spaces of arbitrary dimension. Element non‐conformity is defined as the difference between a given size specification map, in the form of a Riemannian metric tensor, and the actual metric tensor of the element. An approach to the measurement of non‐conformity coefficients of non‐simplicial elements based on sub‐simplex division is proposed. An analysis of the measure's behaviour presented for quadrilaterals, hexahedra, prisms and pyramids shows that the measure is sensitive to size, stretching and orientation variations, as well as to other types of element shape degeneration. Finally, numerical applications show that the metric conformity measure can be used as a quality measure to quantify the discrepancy between a whole non‐simplicial mesh and a complex anisotropic size specification map. Copyright © 2005 John Wiley & Sons, Ltd.     

Structural damage diagnosis using incomplete static responses and LS-SVM

This paper presents novel approach to structural damage detection and estimation using incomplete static responses of a damaged structure and least squares support vector machine (LS-SVM). The presented method is based on the reduced stiffness matrix to formulate incomplete static responses as input parameters to the LS-SVM. The presented method is applied to a plane steel bridge, a four-span continuous beam and four-storey plane frame containing several damages. Also, the effect of the discrepancy in stiffness between the finite element model and the actual tested system has been investigated. The results show that the presented method is sensitive to the location and severity of the structural damage in spite of the incomplete noisy data and modelling errors.