Modeling a Free Burnishing of a Powder Hollow Cylinder

2021 ◽  
Vol 410 ◽  
pp. 372-379
Author(s):  
Lyudmila Ryabicheva ◽  
Valery V. Dyadichev ◽  
Denis V. Reshetnyak
Keyword(s):  
Relative Density ◽  
Hollow Cylinder ◽  
Computer Modelling ◽  
Initial Porosity ◽  
Porous Bodies ◽  
Inner Surface ◽  
Sintered Powder ◽  
Hollow Cylinders ◽  
The Impact ◽  
The Mathematical Model

The paper presents the results of the computer modelling of the stressed state and relative density when burnishing a porous hollow cylinder, made from copper sintered powder material. The mathematical model, based on the theory of porous bodies’ plasticity, is used for the analysis. The paper researches the impact of the initial porosity of the material on the effective stresses distribution, relative density and force change when free burnishing of hollow cylinders. It is ascertained that with the decrease of the initial porosity of the sintered material there is the increase of the burnishing force, stresses rate and relative density on the inner sur-face of a hollow cylinder. For porous materials at a certain stage of burnishing, the deformation zone is transformed into the compaction zone with a high relative density which de-creases while moving away from the inner surface of hollow cylinders. The maximum value of the relative density is implemented directly on the inner surface of hollow cylinders; along with this the density value is evenly distributed on the inner wall.

scholarly journals Research of brick dynamic strength when subjected to shock loading by method of computer modelling

2019 ◽  
Vol 221 ◽  
pp. 01041
Author(s):  
Andrei Plyaskin ◽  
Nikolai Belov ◽  
Nikolai Yugov ◽  
Artem Ryshkov ◽  
Aleksei Yugov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Shock Wave ◽  
Shock Loading ◽  
Computer Modelling ◽  
Dynamic Strength ◽  
Drop Weight ◽  
The Impact ◽  
The Mathematical Model

The study represents the mathematical model of distorting and destruction of ordinary brick and masonry when subjected to shock-wave loadings. The research of the impact dynamic strength of the masonry's two fragments to the steel drop-weight of 1-2 m, weighing 197-1000 kg, was conducted by using the method of the computer modelling.

scholarly journals The Impact of Elongation on Change in Electrical Resistance of Electrically Conductive Yarns Woven into Fabric

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3390
Author(s):  
Željko Knezić ◽  
Željko Penava ◽  
Diana Šimić Penava ◽  
Dubravko Rogale
Keyword(s):  
Mathematical Model ◽  
Electrical Resistance ◽  
Electrically Conductive ◽  
Textile Materials ◽  
Measurement Results ◽  
Conductive Yarns ◽  
Yarn Count ◽  
As Relationship ◽  
The Impact ◽  
The Mathematical Model

Electrically conductive yarns (ECYs) are gaining increasing applications in woven textile materials, especially in woven sensors suitable for incorporation into clothing. In this paper, the effect of the yarn count of ECYs woven into fabric on values of electrical resistance is analyzed. We also observe how the direction of action of elongation force, considering the position of the woven ECY, effects the change in the electrical resistance of the electrically conductive fabric. The measurements were performed on nine different samples of fabric in a plain weave, into which were woven ECYs with three different yarn counts and three different directions. Relationship curves between values of elongation forces and elongation to break, as well as relationship curves between values of electrical resistance of fabrics with ECYs and elongation, were experimentally obtained. An analytical mathematical model was also established, and analysis was conducted, which determined the models of function of connection between force and elongation, and between electrical resistance and elongation. The connection between the measurement results and the mathematical model was confirmed. The connection between the mathematical model and the experimental results enables the design of ECY properties in woven materials, especially textile force and elongation sensors.

Thermal performance comparison of different sun tracking configurations

2019 ◽  
Vol 88 (2) ◽  
pp. 20902
Author(s):  
O. Achkari ◽  
A. El Fadar
Keyword(s):  
Thermal Performance ◽  
Electricity Generation ◽  
Arid Regions ◽  
Performance Comparison ◽  
Water Desalination ◽  
Parabolic Trough ◽  
Parabolic Trough Collector ◽  
The Impact ◽  
The Mathematical Model ◽  
Good Agreement

Parabolic trough collector (PTC) is one of the most widespread solar concentration technologies and represents the biggest share of the CSP market; it is currently used in various applications, such as electricity generation, heat production for industrial processes, water desalination in arid regions and industrial cooling. The current paper provides a synopsis of the commonly used sun trackers and investigates the impact of various sun tracking modes on thermal performance of a parabolic trough collector. Two sun-tracking configurations, full automatic and semi-automatic, and a stationary one have numerically been investigated. The simulation results have shown that, under the system conditions (design, operating and weather), the PTC's performance depends strongly on the kind of sun tracking technique and on how this technique is exploited. Furthermore, the current study has proven that there are some optimal semi-automatic configurations that are more efficient than one-axis sun tracking systems. The comparison of the mathematical model used in this paper with the thermal profile of some experimental data available in the literature has shown a good agreement with a remarkably low relative error (2.93%).

scholarly journals Fractal diffusion of silver ions in hollow cylinders with unsmooth inner surface

2019 ◽  
Vol 14 ◽  
pp. 155892501989564
Author(s):  
Ling Lin ◽  
Shao-Wen Yao
Keyword(s):  
Fractal Dimension ◽  
Hollow Fiber ◽  
Theoretical Basis ◽  
Silver Ions ◽  
Present Theory ◽  
Ion Release ◽  
Practical Applications ◽  
Fractal Derivative ◽  
Inner Surface ◽  
Hollow Cylinders

This article studies the ion release from an unsmooth inner surface of a hollow fiber. A fractal diffusion model is established using the fractal derivative, and the effect of the fractal dimension on the ion release is elucidated. The present theory provides a theoretical basis for the optimization of a hollow fiber contained silver ions for practical applications.

Mechanical Response of Porous Copper Manufactured by Lost Carbonate Sintering Process

2007 ◽  
Vol 539-543 ◽  
pp. 1863-1867 ◽  
Author(s):  
X.F. Tao ◽  
Li Ping Zhang ◽  
Y.Y. Zhao
Keyword(s):  
Particle Size ◽  
Flexural Strength ◽  
Relative Density ◽  
Mechanical Response ◽  
Compaction Pressure ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Three Point Bending ◽  
Porous Copper ◽  
The Impact

This paper investigated the mechanical response of porous copper manufactured by LCS under three-point bending and Charpy impact conditions. The effects of the compaction pressure and K2CO3 particle size used in producing the porous copper samples and the relative density of the samples were studied. The apparent modulus, flexural strength and energy absorption capacity in three-point bending tests increased exponentially with increasing relative density. The impact strength was not markedly sensitive to relative density and had values within 7 – 9 kJ/m2 for the relative densities in the range 0.17 – 0.31. The amount of energy absorbed by a porous copper sample in the impact test was much higher than that absorbed in the three-point bending test, impling that loading strain rate had a significant effect on the deformation mechanisms. Increasing compaction pressure and increasing K2CO3 particle size resulted in significant increases in the flexural strength and the bending energy absorption capacity, both owing to the reduced sintering defects.

The Impact Analysis of Revolute Pair Clearance to the End Pose Accuracy of Welding Robot

2015 ◽  
Vol 778 ◽  
pp. 259-263
Author(s):  
Fa Jun Zhang ◽  
Lin Zi Li ◽  
Hui Lin ◽  
Yin Lin Pu ◽  
Zhu Xin
Keyword(s):  
Mathematical Model ◽  
Impact Analysis ◽  
Joint Clearance ◽  
Welding Robot ◽  
Movement Characteristic ◽  
Movement Stability ◽  
Simulation Results ◽  
The Impact ◽  
The Mathematical Model ◽  
Welding Position

Various uncertain factors affect the movement of the welding robot, thus welding gun tend to deviate from the theory of welding position which reduces the welding accuracy, of which the revolute pair clearance have an greater effect on the movement of the welding robot. In order to study the influence of revolute pair clearance to the end pose accuracy of welding robot, the mathematical model of revolute pair clearance was established, and the software SolidWorks was used for establishing the welding robot model, making simulations of the mechanical arm with joint clearance and no joint clearance. At last, the movement characteristic of the hinge shaft is attained. The simulation results showed that the shaft velocity and displacement of mechanical arm with joint clearance has a certain degree of fluctuation, which affecting the end pose accuracy of welding robot , and reducing the movement stability and the welding accuracy of welding robot.

Boiling Heat Transfer Characteristics of Rotary Hollow Cylinders with In-Line and Staggered Multiple Arrays of Water Jets

2021 ◽  
Author(s):  
Mohammad Jahedi ◽  
Bahram Moshfegh
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Stagnation Point ◽  
Surface Heat Flux ◽  
Surface Heat ◽  
Maximum Heat ◽  
Water Jets ◽  
Maximum Heat Flux ◽  
Inner Surface ◽  
Hollow Cylinders

Abstract Transient heat transfer studies of quenching rotary hollow cylinders with in-line and staggered multiple arrays of jets have been carried out experimentally. The study involves three hollow cylinders (Do/d = 12 to 24) with rotation speed 10 to 50 rpm, quenched by subcooled water jets (ΔTsub=50-80 K) with jet flow rate 2.7 to 10.9 L/min. The increase in area-averaged and maximum heat flux over quenching surface (Af) has been observed in the studied multiple arrays with constant Qtotal compared to previous studies. Investigation of radial temperature distribution at stagnation point of jet reveals that the footprint of configuration of 4-row array is highlighted in radial distances near the outer surface and vanishes further down toward the inner surface. The influence of the main quenching parameters on local average surface heat flux at stagnation point is addressed in all the boiling regimes where the result indicates jet flow rate provides strongest effect in all the boiling regimes. Effectiveness of magnitude of maximum heat flux in the boiling curve for the studied parameters is reported. The result of spatial and temporal heat flux by radial conduction in the solid presents projection depth of cyclic variation of surface heat flux in the radial axis as it disappears near inner surface of hollow cylinder. In addition, correlations are proposed for area-averaged Nusselt number as well as average and maximum local heat flux at stagnation point of jet for the in-line and staggered multiple arrays.

Enhancement the Solar Still Performance Using Chimney Exhaust Gases

2021 ◽  
Author(s):  
Hamdy Hassan
Keyword(s):  
Mathematical Model ◽  
Theoretical Study ◽  
Saline Water ◽  
Kutta Method ◽  
Solar Still ◽  
Climate Conditions ◽  
Exhaust Gases ◽  
Runge Kutta Method ◽  
The Impact ◽  
The Mathematical Model

Abstract In this paper, a theoretical study is presented on enhancement of the solar still performance by using the exhaust gases passing inside a chimney under the still basin. The impact of the exhaust gases temperature on the solar still temperature, productivity, and efficiency are considered. The performance of solar still with chimney is compared with that of conventional solar still. The study is carried out under the hot and climate conditions of Upper Egypt. A complete transient mathematical model of the physical model including the solar still regions temperatures, productivity, and heat transfer between the solar still and the exhaust gases are constructed. The mathematical model is solved numerically by using fourth-order Runge-Kutta method and is programmed by using MATLAB. The mathematical model is validated using an experimental work. The results show that the solar still saline water temperature increases and productivity with using and rising the exhaust gases. Furthermore, the impact of using exhaust gases on the still performance in winter is greater than in summer. using chimney exhaust gases at 75 °C and 125 °C enhances the daily freshwater yield of the conventional still by more than three times and about six times in winter, respectively, and about two and half times and more than three times in summer, respectively.

Exact impact response of multi-layered cement-based piezoelectric composite considering electrode effect

2018 ◽  
Vol 30 (3) ◽  
pp. 400-415 ◽  
Author(s):  
Taotao Zhang ◽  
Keping Zhang ◽  
Wende Liu
Keyword(s):  
Analytical Method ◽  
Virtual Work ◽  
Impact Load ◽  
Summation Method ◽  
Impact Response ◽  
Piezoelectric Composite ◽  
Smart Devices ◽  
Natural Modes ◽  
The Impact ◽  
The Mathematical Model

Multi-layered cement-based piezoelectric composites could enable accurate real-time detection of the concrete structure deformation induced by impact load. An analytical method for quantifying the impact response of the multi-layered cement-based piezoelectric composite is established based on the piezo-elasticity, and a general transfer matrix description for the composite with any number of layers is derived. The motion of the composite is decomposed into natural modes according to its physical significance of vibration modes. The mechanical and electrical solutions are obtained via the mode summation method and the virtual work principle. In order to give a clear demonstration, some numerical simulations are conducted to verify the validity of the theoretical analysis. Moreover, the current analytical method considers the electrode as an extra layer and evaluates the effect of its thickness and material on the performance of the multi-layered cement-based piezoelectric composite. It can be seen that the mathematical model presented in this article provides a rigorous tool for the analysis of the multi-layered cement-based piezoelectric composite and therefore could benefit the design of certain types of smart devices under impact load.

scholarly journals Modelling of motorway bridge spans under modernization with consideration of rheological properties of the materials

2018 ◽  
Vol 234 ◽  
pp. 04004 ◽  
Author(s):  
Alexey Lobiak ◽  
Andrii Plugin ◽  
Larisa Kravtsiv ◽  
Oksana Kovalova
Keyword(s):  
Rheological Properties ◽  
Computer Modelling ◽  
Concrete Slab ◽  
Kinetic Curve ◽  
Modelling Technique ◽  
Reinforced Concrete Slab ◽  
Program Complex ◽  
Building Information ◽  
Lev Landau ◽  
The Impact

The paper presents a computer modelling technique for modernization of bridgework operations by building-up a mounted reinforced concrete slab. It implements the technique of the evolutionary transformation of a model in one calculation cycle with redistribution of forces between the elements of the built-up section, and consideration of the impact of elastoplastic and rheological properties of the materials. Consideration of the concrete creep implies the application of the generalized kinetic curve of prolonged deformation and phenomenological deformation development equations based on the colloid-chemical concept of the prolonged concrete deformation mechanism. The creep control was implemented through new structural coefficients which determined the structure of matrix interlayers between the sand grains, and mortar between the crushed stone grains. The technique proposed was realized in the program complex “LIRA-SAPR” based on the building information modelling (BIM) and the finite element method (FEM). The multistage modelling technique was shown by an example of calculation of a motorway bridge slab span within the transport structures under modernization along the Lev Landau Avenue in Kharkiv (Ukraine).

Sign in / Sign up

Export Citation Format

Share Document