scholarly journals SIZE DEPENDENCES OF LINEAR EXPANSION AND VOLUME ELASTICITY OF MONO- AND BIMETALLIC NANOCLUSTERS

2020 ◽  
pp. 260-273
Author(s):  
Владимир Сергеевич Мясниченко ◽  
Николай Юрьевич Сдобняков ◽  
Анатолий Николаевич Базулев ◽  
Павел Михайлович Ершов ◽  
Екатерина Михайловна Давыденкова
Keyword(s):  
Molecular Dynamics ◽  
Analytical Model ◽  
Expansion Coefficient ◽  
Linear Expansion ◽  
Tight Binding ◽  
Relative Increase ◽  
Binding Potential ◽  
Linear Expansion Coefficient ◽  
Bimetallic Nanoclusters ◽  
Coefficient Of Linear Expansion

Проведена серия молекулярно-динамических экспериментов по охлаждению разупорядоченных металлических наночастиц Au, Cu, Al,Ti и биметаллических наносплавов Au - Cu и Ti - Al с использованием потенциала сильной связи. Получены размерные зависимости коэффициента линейного расширения и модуля упругости для моно- и биметаллических частиц. В первом приближении размерная зависимость коэффициента линейного расширения обратно пропорциональна соответствующей зависимости для температуры плавления наночастицы, что коррелирует с аналитической моделью. Молекулярно-динамические результаты предсказывают более умеренный относительный рост коэффициента линейного расширения, по сравнению с аналитической моделью. Установлено, что модуль упругости увеличивается с уменьшением размера наночастиц. A series of molecular dynamics experiments on cooling disordered Au,Cu, Al,Ti metal nanoparticles and Au - Cu, Ti - Al bimetallic nanoalloys using the tight-binding potential have been performed. The size dependences of the temperature coefficient of linear expansion and the elasticity modulus for mono- and bimetallic particles are obtained. In the first approximation, the size dependence of the linear expansion coefficient is inversely proportional to the corresponding dependence for the melting temperature of a nanoparticle, which correlates with an analytical model. Molecular dynamics results predict a more moderate relative increase in the linear expansion coefficient compared to the analytical model. It was found that the modulus of elasticity increases with decreasing the nanoparticle size.

Influence of Crushed Basalt Aggregate on Crack Resistance of Concrete

2012 ◽  
Vol 253-255 ◽  
pp. 529-532
Author(s):  
Jian Jun Yan ◽  
Shi Hua Zhou ◽  
Shang Shi Peng
Keyword(s):  
Crack Resistance ◽  
Temperature Stress ◽  
Expansion Coefficient ◽  
Linear Expansion ◽  
Drying Shrinkage ◽  
Temperature Deformation ◽  
Linear Expansion Coefficient ◽  
Volume Deformation

The crack resistance of concrete with crushed basalt aggregate was studied. Compared with the limestone concrete, the basalt concrete has larger drying shrinkage and autogenous volume deformation. The linear expansion coefficient of basalt concrete is 1.3×10－6 /°C larger than that of limestone concrete, and it has additional temperature deformation of 24.1×10－6. According to the analysis on temperature-stress of concrete, the cracking temperature of basalt concrete is 8.9°C higher than that of limestone concrete, and the crack resistance of basalt concrete is unfavorable.

scholarly journals Technological Forecasting of Deformations in Flat Parts

2020 ◽  
Vol 3 (1) ◽  
pp. 1-12
Author(s):  
Tatiana N. Ivanova ◽  
Witold Biały ◽  
Jiři Fries ◽  
Victor Nordin
Keyword(s):  
Expansion Coefficient ◽  
Linear Expansion ◽  
Plate Thickness ◽  
Heat Removal ◽  
Quality Parameters ◽  
Grinding Wheel ◽  
Linear Expansion Coefficient ◽  
Plate Material ◽  
Thermal Deformations ◽  
Geometric Size

AbstractThe deformation of a part occurring in the process of grinding directly influences its exploitation and quality parameters. The instability of shape and size, which occurs due to an imbalance of residual stress, can be the one of the major causes of deformation of a part. The decrease in stress slows down the deformation process. Considering the regularities of heat source intensity dependence on the grinding modes, it can be asserted that with increasing grinding depth and grinding wheel hardness, the value increases and it decreases with a growth in a speed of the part and the use of cooling. The higher the heat removal is and the better lubricant properties of the liquid are, the more significant the decrease in is. Changing these values allows regulation of the residual stresses. As a result of the research on determination of deformations, it is recommended to reduce thermal deformations by considering the geometric size of a plate to be machined, linear expansion coefficient of plate material and an allowance for nonflatness from thermal deformations. The value of nonflatness from thermal deformations is directly proportional to linear expansion coefficient of plate material and its square overall dimensions. At the same time, the value of nonflatness is inversely proportional to the plate thickness.

Utilization of Doppler effect and laser heterodyne to measure linear expansion coefficient of metal

2018 ◽  
Vol 47 (7) ◽  
pp. 706005
Author(s):  
布音嘎日迪 Bu Yingaridi ◽  
仲维丹 Zhong Weidan ◽  
甄佳奇 Zhen Jiaqi ◽  
高亚臣 Gao Yachen ◽  
刘 勇 Liu Yong ◽  
...  
Keyword(s):  
Expansion Coefficient ◽  
Doppler Effect ◽  
Linear Expansion ◽  
Linear Expansion Coefficient ◽  
Laser Heterodyne

The Effect of Cable Material Characteristics on Suspendome

2010 ◽  
Vol 156-157 ◽  
pp. 1251-1255 ◽  
Author(s):  
Zhi Hua Chen ◽  
Guo Jun Sun ◽  
Zhan Sheng Liu
Keyword(s):  
Elastic Modulus ◽  
High Temperature ◽  
Low Temperature ◽  
Expansion Coefficient ◽  
Linear Expansion ◽  
Steel Structure ◽  
Linear Expansion Coefficient ◽  
Maximum Displacement ◽  
Material Characteristics ◽  
Prestressed Steel Structure

Cable is the key component in the prestressed steel structure. In order to study the effect of cable elastic modulus and expansion coefficient on the prestressed steel structure, Suspendome of Tianbao Center was taken as the research object and APDL language is applied to write a corresponding program, thereby carrying out analysis to the model; The results indicate that the change of cable expansion coefficient and cable elastic modulus have a different effect on the performance of the suspendome: at high temperature, the effect of the expansion coefficient of hoop cable and radial cable is larger on the maximum displacement; at low temperature, the effect of the elastic modulus of hoop cable is larger on the support constrained force. Therefore, it is necessary to give precise linear expansion coefficient and elastic modulus for different cables.

scholarly journals SIMULATION OF THE FRACTAL METAL FILMS FORMATION

2020 ◽  
pp. 424-437
Author(s):  
Дмитрий Викторович Иванов ◽  
Сергей Александрович Васильев ◽  
Николай Юрьевич Сдобняков ◽  
Елена Владимировна Романовская ◽  
Виталий Александрович Анофриев ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Beam ◽  
Gold Film ◽  
Tight Binding ◽  
Copper Surface ◽  
Metal Films ◽  
Binding Potential ◽  
Fractal Structures ◽  
Software Product ◽  
Dynamics Method

В данной работе методом молекулярной динамики с использованием потенциала сильной связи проведено моделирование процесса молекулярно-лучевой эпитаксии с целью определения закономерностей при формировании фрактальных металлических пленок на твердой поверхности. В качестве подложки использовалась медь, пленка формировалась из атомов золота. Показана возможность формирования фрактальных структур в островковой пленке золота на поверхности меди. Различными аналитическими методами с использованием программного продукта Gwyddion проанализирован диапазон изменения фрактальной размерности при различных условиях молекулярно-динамического эксперимента. In this work, molecular dynamics method and the tight binding potential was used to simulate the process of the molecular beam epitaxy in order to determine regularities in the formation of fractal metal films on a solid surface. Copper was used as a substrate, the film was formed from gold atoms. The possibility of formation of fractal structures in an island gold film on the copper surface is shown. Various analytical methods using the Gwyddion software product have used to analyze a range of changes in the fractal dimension under different conditions of molecular dynamics experiment.

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