Spatial and orientational distribution of cracks in crystalline photovoltaic modules generated by mechanical load tests

2011 ◽  
Vol 95 (11) ◽  
pp. 3054-3059 ◽  
Author(s):  
Sarah Kajari-Schröder ◽  
Iris Kunze ◽  
Ulrich Eitner ◽  
Marc Köntges
Keyword(s):  
Mechanical Load ◽  
Photovoltaic Modules ◽  
Orientational Distribution ◽  
Load Tests

scholarly journals Failure Trends of High-Voltage Porcelain Insulators Depending on the Constituents of the Porcelain

2020 ◽  
Vol 10 (2) ◽  
pp. 694 ◽  
Author(s):  
Simpy Sanyal ◽  
Taeyong Kim ◽  
Junsin Yi ◽  
Ja-Bin Koo ◽  
Ju-Am Son ◽  
...  
Keyword(s):  
Mechanical Load ◽  
X Ray ◽  
Weight Percentage ◽  
Mechanical And Electrical Properties ◽  
Hardness Tests ◽  
Load Tests ◽  
Porcelain Insulators ◽  
Power Utilities ◽  
The Impact ◽  
High Voltage Porcelain

The aging of porcelain insulators is responsible for the failure of power utilities. Porcelain insulators from different places in South Korea, possessing various aging times and years of installation, have been investigated to carry out lifetime statistics. These samples have a mass of 36,000 lbs and are operated at 154 kV. X-ray fluorescence (XRF) and scanning electron microscopy (SEM) were performed on the porcelain bodies of the samples collected. XRF and SEM revealed trends in the weight percentage of SiO2, Al2O3, and Fe2O3 in the porcelain bodies of the collected samples. The SiO2 and Fe2O3 weight percentage reduced to 8.93% and 73.17%, respectively, in sample C compared to A. However, the Al2O3 weight percentage increased to 16.23% in sample C compared to sample A. This change in weight percentage of SiO2, Fe2O3, and Al2O3 contributed toward enhancing the mechanical and electrical properties of the insulators. Mechanical load tests with electrical voltage (M&E), thermal and mechanical load tests (T&M), and hardness tests (HRB) were performed to evaluate these characteristics. Experiments revealed an increase of 90.9% in the inequality factor (K) in sample C compared to A. The impact of constituents of porcelain on the lifetime expectancy of a porcelain insulator was reported by implementing statistical strategies, such as the Weibull distribution.

The Influence of Initial Commutator Surface Roughness on Wear of the Starter Motor Commutation System

2014 ◽  
Vol 966-967 ◽  
pp. 96-102
Author(s):  
Tanja Spremberg ◽  
Ingo Engler ◽  
Berend Denkena
Keyword(s):  
Surface Roughness ◽  
Steady State ◽  
Mechanical Load ◽  
Life Time ◽  
The Other ◽  
Initial Surface ◽  
Test Rig ◽  
Starter Motor ◽  
Tribological System ◽  
Load Tests

One way to improve the run-in period of the commutation system of an electrical motor is the modification of the commutator ́s roughness. The reduction of the run-in period affects the wear during the motor life time. Therefore, within this paper the influence of the initial commutator roughness on the run-in period and the electromechanical wear is investigated. The research is done with a special starter components test rig. During the tests the wear is analyzed while the applied electromechanical and mechanical load is varied in order to enforce different wear behaviors. It is expected that with an optimal initial surface roughness the amount of wear is reduced until the steady state has been reached. However, the results revealed that there is no significant influence of the initial surface roughness on the examined electromechanical tribological system. It was found, that the mechanical wear of the commutator and the brushes is similar to the electromechanical wear during the run-in period. The run-in period of the mechanical load tests is shorter compared to the other experiments.

Study on Electrical Characteristics of 550 kV GIL Three-post Insulator After Mechanical Load Tests

2021 ◽  
Author(s):  
Ruodong Huang ◽  
Chao Gao ◽  
Fusheng Zhou ◽  
Guoli Wang ◽  
Yao Zheng ◽  
...  
Keyword(s):  
Mechanical Load ◽  
Electrical Characteristics ◽  
Load Tests ◽  
Post Insulator

Experimentally Applied Mechanical Load to the Human Knee Systematically Affects the Morphology of Articular Cartilage

2018 ◽  
Author(s):  
Grischa Bratke ◽  
Steffen Willwacher ◽  
David Maintz ◽  
Gert-Peter Brüggemann
Keyword(s):  
Articular Cartilage ◽  
Mechanical Load ◽  
Human Knee

Point Load Tests on Double Tee Flanges

PCI Journal ◽  
1991 ◽  
Vol 36 (4) ◽  
pp. 66-73
Author(s):  
Alex Aswad George Burnley
Keyword(s):  
Point Load ◽  
Load Tests

Physical methods of research and monitoring

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 35-44
Author(s):  
S. G. Sandomirski
Keyword(s):  
Heat Treatment ◽  
Coercive Force ◽  
Remanent Magnetization ◽  
Structural Changes ◽  
Mechanical Load ◽  
Magnetic Hysteresis ◽  
Steel Structures ◽  
Magnetic Characteristics ◽  
Magnetic Parameters ◽  
Saturation Intensity

The main magnetic parameters sensitive to the structure of steels are the parameters of their saturation loop of magnetic hysteresis: the coercive force Hcs and remanent magnetization Mrs. The saturation magnetization or saturation intensity Mr is most sensitive to the phase composition of steels. The variety of steel grades and modes of technological treatment (e.g., heat treatment, mechanical load) determined the use of magnetic structurescopy and magnetic characteristics — the coercive force Hc, remanent magnetization Mr , and specific hysteresis losses Wh on the subloops of the magnetic hysteresis of steels — as control parameters in diagnostics of the stressed and structural states of steel structures and pipelines. It has been shown that changes in Hc, Mr , and Wh are more sensitive to structural stresses and structures of steels than the parameters of the saturation hysteresis loop of magnetic hysteresis (Hcs, Mrs, and Mrs). The formulas for calculating Hc, Mr and Wh are presented to be used for estimation of changes in the parameters upon heat treatment of steels. Features of the structural sensitivity of the subloop characteristics and expediency of their use for magnetic structural and phase analyzes are determined. Thus, the range of changes in Ìr attributed to the structural changes in steels upon gradual Hm decrease is many times wider compared to the range of possible changes in Mrs under the same conditions. Conditions (relations between the magnetic parameters) and recommendations regarding the choice of the field strength Hm are given which provide the justified use of Hc, Mr and Wh parameters in magnetic structurescopy

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