Determination of cross-sectional area of conductors and selection of protective devices

2012 ◽  
2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.


2007 ◽  
Vol 391 (1) ◽  
pp. 118-123 ◽  
Author(s):  
Jeremy McMinis ◽  
Rene Crombez ◽  
Eva Montalvo ◽  
Weidian Shen

2018 ◽  
Vol 224 ◽  
pp. 02083
Author(s):  
Gleb Volkov ◽  
Vladimir Smirnov

The systematization of planetary rotary hydraulic machines (PRHM) with floating rollers is presented in the article. This systematization is carried out according to such structural features as: the number of waves that have central tooth gears with internal and external teeth, the character of the leading link motion; selection of a supporting (fixed) link; selection of the link containing the channels. The systematization allows us to list all essentially different schemes of PRHM and conduct their comparative analysis. The comparison is based on such technical parameters as: symmetry of schemes; absence of dead spots; PRHM performance, pulsation of instantaneous performance; channel cross-sectional area. The comparison showed that based on a set of indicators, the schemes with the numbers of central wheel waves 2×4; 4×6; 6×8 are preferred, in which the rotor performs a purely rotary motion.


Cellulose ◽  
2019 ◽  
Vol 26 (8) ◽  
pp. 4693-4706 ◽  
Author(s):  
Hangbo Yue ◽  
Juan C. Rubalcaba ◽  
Yingde Cui ◽  
Juan P. Fernández-Blázquez ◽  
Chufen Yang ◽  
...  

2015 ◽  
Vol 1083 ◽  
pp. 111-117
Author(s):  
Xi Ying Yang ◽  
Ou Yang Ting ◽  
You Qing Fei

Cross sectional area of single filaments, a key parameter to characterize fiber properties, was experimentally studied using a desktop scanning electron microscope. Three different methods are employed based on the pixel area, averaged diameter and single diameter measurements, respectively. Results have shown that all three methods can achieve accurate measurement results once the axis of fiber sample is kept parallel to the electron beam. Significant errors are generated for the fiber samples with their axis tilted, which may frequently occur as a sample prepared. For circular fibers, a single diameter measured from tilted fibers is sufficient to determine their cross sectional area at high precision with COV values below 1.6%. By selecting an appropriate method, a desktop SEM can serve as a convenient and powerful tool for accurate determination of cross sectional area as well as morphological observation.


Sign in / Sign up

Export Citation Format

Share Document