共查询到12条相似文献,搜索用时 93 毫秒
1.
2.
对两种莫尔条纹(光闸条纹和横向条纹)信号的谐波含量以及它们对光栅系统测量精度的影响进行了分析,并用实测数据加以比较,指出在光栅系统中,取横向莫尔条纹信号的谐波量小,正弦性好,细分误差小,在其它参数相同的情况下,可提高系统的测量精度2倍左右。 相似文献
3.
4.
5.
Existing economic and economic-statistical designs require practitioners to specify the Mahalanobis Distance Shift Size (MDSS) as an exact value. However, practitioners may find it difficult to specify this distance. This article proposes the economic and economic-statistical designs of the Hotelling's T2 chart, where practitioners do not have to specify the MDSS. Adopting optimal design parameters based on the wrong MDSS results in a significant increase in cost. In comparison, adopting the optimal design parameters based on the proposed methodology results in a slight increase in cost. This article also studies the effects of different input parameters and statistical constraints. 相似文献
6.
7.
H.‐P. Gnser F. D. Fischer E. A. Werner 《International journal for numerical methods in engineering》2000,48(4):595-611
An iterative method for coupling of numerical simulations on two length scales is presented. The computations on the microscale and on the macroscale are linked via a suitable macroscopic constitutive law. The parameters of this material law depend on the deformation history and are obtained from simulations using microstructurally representative volume elements (RVEs) subjected to strain paths derived from the associated material points in the macroscopic structure. Thus, different constitutive parameter sets are assigned to different regions of the macrostructure. The microscopic and macroscopic simulations are performed iteratively and interact mutually via the strain paths and the constitutive parameters, respectively. As an example, the strip tension test for a porous material is modelled using the finite element (FE) method. The coupling procedure, the material law and its numerical implementation are described. The method is shown to allow for a detailed simulation of the deformation mechanisms both on the micro‐ and the macroscale as well as for an assessment of their interactions while keeping the computational efforts reasonably low. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
8.
针对当今国内市场上已有的钟罩式气体流量标准检定装置在小量程检定时存在的检定效率低,时间浪费的问题,该系统提出了一种基于流媒体(DirectShow)与数字图像处理技术的多工位燃气表检定方法,可有效地提高检定效率,使原有的检定系统装置更加完善,自动化的程度更高,使之能在工业上更加广泛的应用. 相似文献
9.
I. I. Dunin-Barkovskii 《Measurement Techniques》2004,47(12):1168-1173
A 3D machine vision system based on a television camera and laser for controlling the large dimensions of large-scale parts is considered. The laser ensures structured illumination of the surface of the object, making it possible to obtain three-dimensional coordinates of representative points of the measurement object using a triangulation method and a parametric model. An approach to calibration of the model by means of a special target is presented.Translated from Izmeritelnaya Tekhnika, No. 12, pp. 24–26, December, 2004.This revised version was published online in April 2005 with a corrected cover date. 相似文献
10.
11.
G. Alfano M. A. Crisfield 《International journal for numerical methods in engineering》2003,58(7):999-1048
The paper describes a local‐control arc‐length method which can be combined with various forms of line‐search procedure. In particular, a new ‘double‐line‐search’ method is developed, which significantly improves the solution procedure and turns out to be efficient and robust. Although the potential range of applications is wide, the method is here limited to the finite element analysis of delamination in a laminated composite using a cohesive‐zone model combined with interface elements. Three problems have been analysed and comparisons have been made with experimental results. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
12.
Influences of testing technique and frequency on the fatigue behaviour of 50CrMo4 and EN AW-5083 were investigated. To clarify the effect of test frequency on the fatigue behaviour, tests with 20 kHz and f < 400 Hz were performed. The frequency effect can be caused by temperature, environment and strain rate. For the aluminium alloy, the influence of environment is responsible for the dependence of fatigue lifetime on the frequency. The fatigue lifetime of the steel showed in both environments similar frequency dependency, i.e. the strain rate is assumed to be responsible for the differences in fatigue lifetime. 相似文献