Stress Distributions in an Elastic Body due to Molecular Interactions Considering One-Dimensional Periodic Material Distribution Based on Mindlin Solution

2018 ◽  
Author(s):  
Hiroshige Matsuoka ◽  
Toshiki Otani ◽  
Shigehisa Fukui
Keyword(s):  
Stress Distribution ◽  
Elastic Body ◽  
Molecular Interactions ◽  
Material Distribution ◽  
Stress Distributions ◽  
One Dimensional ◽  
Calculation Results ◽  
Basic Characteristics ◽  
The One

A method to calculate the stress distributions in the elastic body caused by the molecular interactions has been established. The stress distribution was calculated based on the Mindlin’s solution considering the one-dimensional periodic material distribution. The calculation results for a distribution of two materials were presented. The basic characteristics of the stress distribution in the elastic body were quantitatively clarified.

Analysis of the Containment Thermal-Hydraulic Behavior of a Small Reactor During Loss of Coolant Accident

2017 ◽  
Author(s):  
Qian Lin ◽  
Weizhong Zhang
Keyword(s):  
Cooling System ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Loss Of Coolant Accident ◽  
Lumped Parameter ◽  
Loss Of Coolant ◽  
Calculation Results ◽  
The One

The containment thermal hydraulics of a small reactor during loss of coolant accident (LOCA) is studied by a lumped parameter one-dimensional model and a three-dimensional model. The capability of a kind of heat exchanger type passive containment cooling system (PCCS) is analyzed by the one-dimensional model. The calculation results show that, the decay heat can be removed and the containment pressure can be decreased by the proposed PCCS. The steam and non-condensable gas (the air) distribution in the containment is investigated, the mixing and stratification behaviors are analyzed for several different cases, in which the PCCS and condenser are located at higher, base or lower position. The sensitivity analysis of the PCCS elevation shows that, in despite of the different gas stratification, the containment pressures are nearly the same. Similar conclusions can be obtained by the one-dimensional model and three-dimensional model. The preliminary results may indicate that, the designed PCCS and condenser can be located at a lower part, which will be benefit for the economy of the small reactor or meet other requirements.

scholarly journals NUMERICAL IMPLEMENTATION OF FRETTING WEAR IN THE FRAMEWORK OF THE MDR

2019 ◽  
Vol 17 (1) ◽  
pp. 87
Author(s):  
Qiang Li ◽  
Fabian Forsbach ◽  
Justus Benad
Keyword(s):  
Numerical Calculation ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Fretting Wear ◽  
Numerical Implementation ◽  
One Dimensional ◽  
Method Of Dimensionality Reduction ◽  
Improve Accuracy ◽  
The One ◽  
Archard’S Law Of Wear

Two numerical methods are proposed to improve accuracy of the numerical calculation of fretting wear in the framework of the Method of Dimensionality Reduction (MDR). Due to the singularity of the transformation equations, instabilities appear at the border between the stick and slip regions after many transformations from the one-dimensional to the three-dimensional contact and back. In these two methods, the transformation equations are reformulated to weaken the singularity of the integrals and a stable simulation of fretting wear is realized even with the wear models which go beyond the classical Archard law. With an example of dual-oscillation, we show the change in the worn profile of a parabolic indenter as well as the stress distribution on the contacting surface during the oscillating cycles under the Archard’s law of wear and Coulomb’s law of friction.

Effective Static and Dynamic Finite Element Modeling of a Double Swept Composite Rotor Blade

2020 ◽  
Vol 65 (3) ◽  
pp. 1-12 ◽  
Author(s):  
Matteo Filippi ◽  
Enrico Zappino ◽  
Erasmo Carrera ◽  
Bruno Castanié
Keyword(s):  
Finite Element ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Stress Distributions ◽  
One Dimensional ◽  
Helicopter Blades ◽  
Mechanical Responses ◽  
Solid Finite Elements ◽  
The One ◽  
Complicated Geometries

The paper concerns mechanical responses of helicopter blades made of composite materials. Structures with complicated geometries are modeled by using both beam and solid finite elements. The adopted one-dimensional kinematics only encompasses pure displacements; therefore, the connection with three-dimensional elements can be carried out with ease. Contributions to elastic and inertial matrices deriving from nodes shared by beams and solids are merely summed together through a standard assembling procedure. Stress, free vibration, and time response analyses have been performed on different configurations. A straight metallic rotating structure and a swept-tip blade made of an orthotropic material have been considered for verification and validation purposes. Current results have been compared with experimental data and numerical solutions available in the literature. Furthermore, a straight and a double-swept blade with a realistic airfoil have been studied. For the straight configuration, the one-dimensional results have been compared with finite element solutions obtained with commercial software. The methodology enabled complicated stress distributions and coupling phenomena to be predicted with reasonable accuracy and affordable computational efforts.

scholarly journals МОДЕЛИРОВАНИЕ ЭНЕРГЕТИЧЕСКИХ ХАРАКТЕРИСТИК СТРУЙНО-РЕАКТИВНОЙ ТУРБИНЫ

2020 ◽  
pp. 22-27
Author(s):  
Сергій Михайлович Ванєєв ◽  
Микола Іванович Радченко ◽  
Станіслав Станіславович Мелейчук ◽  
Вадим Миколайович Бага ◽  
Тетяна Сергіївна Родимченко
Keyword(s):  
Software Package ◽  
Aerodynamic Drag ◽  
Point Of View ◽  
Stationary Mode ◽  
Rotor Speed ◽  
Dimensional Theory ◽  
One Dimensional ◽  
Calculation Results ◽  
The Moment ◽  
The One

The aim of the work is to develop a methodology for studying the gas flow in the flowing part of a jet-reactive turbine stage, consisting of a supply nozzle and an impeller, using the FlowVision software package, as well as calculating the parameters and characteristics of this stage. In the process of modeling and research, a large number of types of boundary conditions, initial grids and adaptation levels, time calculation steps, etc. were used and verified. The results of calculations of the energy characteristics of a jet-reactive turbine when setting the pressure and temperature of the braked flow at the inlet to the stage 701325 Pa (overpressure - 600000 Pa) and 288 K, respectively, and the static pressure at the exit from the stage 1010325 Pa are presented. The characteristics of the turbine on the circumference of the impeller, that is, without taking into account the moment of aerodynamic drag during rotation of the turbine rotor in a viscous gas environment are received. The main parameter necessary for calculating the power and efficiency of the turbine is the moment. It is shown that the circumferential (driving) moment of a jet-reactive turbine during calculations using the FlowVision software package can be determined in several ways, based on the results of the calculated parameters displayed in the information window. Comparison of the values of the driving moment obtained in different ways, including the one-dimensional theory, showed that they differ slightly: up to 12%. The dependences of the change in this moment on the rotor speed are given. The values efficiency of the circumferential power and circumferential efficiency on the rotor speed are obtained, and they are compared with the results of calculating these dependences according to the one-dimensional theory for the calculated and non-calculated regime of flow from the driving nozzle. The highest values of the peripheral power and peripheral efficiency are achieved in the range of rotation speed values of 24000-26000 rpm; maximum values of efficiency are in the range of 45-48%. It is shown that the proposed technique is the most reliable from the point of view of the adequacy of the processes inside the machine and the time-spending from the point of view of calculating the stationary mode. Verification of the obtained results was carried out according to the dependence of the starting moment on the pressure at the inlet of the jet-reactive turbine through comparing the calculation results by using the FlowVision software package with experimental data and the calculation results according to the one-dimensional theory.

Stress Distribution in Rotating Discs with Non-Central Holes

1964 ◽  
Vol 15 (2) ◽  
pp. 107-121 ◽  
Author(s):  
W. A. Green ◽  
G. T. J. Hooper ◽  
R. Hetherington
Keyword(s):  
Stress Distribution ◽  
Numerical Solution ◽  
Plane Stress ◽  
Two Dimensional ◽  
Stress Distributions ◽  
Uniform Thickness ◽  
Dimensional Model ◽  
One Dimensional ◽  
Rotating Discs ◽  
Good Agreement

SummaryThe stress distribution in rotating circular discs containing a central hole and a symmetrical array of non-central holes is determined by numerical solution of the equations of generalised plane stress. Particular attention is given to an annulus containing the holes and of width approximately eight hole diameters, in which the full two-dimensional equations are solved. The region outside this annulus is treated as radially symmetric and the stresses there are determined from a simpler one-dimensional model. Stress distributions are reported for uniform discs of fixed geometry containing 10, 20 and 45 holes. Results are also obtained for 20-hole discs of non-uniform thickness comprising a uniformly tapered disc, a disc with a thickened annulus containing the holes, and a uniform disc with each hole surrounded by thickened bosses. As a check on the numerical method, calculations have been carried out on a disc of identical geometry to one examined photoelastically bv Leist and Weber with good agreement. The effect of changing Poisson's ratio for this particular disc is also examined.

Theoretical Study of van der Waals Dispersion Pressures Considering One-Dimensional Material Distributions in In-Plane Direction

2013 ◽  
Author(s):  
Hiroshige Matsuoka ◽  
Niki Kitahama ◽  
Teppei Tanaka ◽  
Shigehisa Fukui
Keyword(s):  
Half Space ◽  
Theoretical Study ◽  
Van Der Waals ◽  
Material Distribution ◽  
Elementary Functions ◽  
One Dimensional ◽  
Single Interface ◽  
Periodic Distribution ◽  
Plane Direction ◽  
Basic Characteristics

The van der Waals (vdW) dispersion pressures between a half-space consisting of a uniform material and a half-space with one-dimensional material distribution in the in-plane direction have been theoretically derived. Two patterns of material distribution were considered here, i.e., a periodic distribution of materials (Pattern 1) and a distribution of two materials with single interface (Pattern 2). The vdW pressure for Pattern 1 was derived based on a Fourier series, while the vdW pressure for Pattern 2 was derived as elementary functions. The basic characteristics of these vdW pressures were clarified.

scholarly journals Transient Thermoelastic Analysis of a Cylinder Having a Varied Coefficient of Thermal Expansion

2020 ◽  
Vol 64 (4) ◽  
pp. 273-278
Author(s):  
Olga Shypul ◽  
Vitalii Myntiuk
Keyword(s):  
Heat Flux ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Transient State ◽  
Maximum Temperature ◽  
Stress Distributions ◽  
One Dimensional ◽  
The One ◽  
Transient Thermal

This paper is concerned with the mathematical modeling of transient thermal elastic problem involving a layered cylinder with a varied coefficient of thermal expansion and powered by a heat flux from an external surfaces. All material's properties are the same for each cylinder's layers, besides the coefficient of linear thermal expansion which is varied and corresponds to hardened and unhardened layers. An obtained solution is a transient state of a heat transfer for the one-dimensional temperature change under the action of heat flux in continuous time. Cumbersome analytical solutions are converted into simple approximation. They are used to solve the inverse problems of the thermal stressed state–determining the time of action of the heat flux to achieve the specified maximum temperature or stress. Some numerical results for the stress distributions are shown in figures.

Theoretical Study of Surface Interaction Stresses Considering One-Dimensional Material Distributions in the In-Plane Direction Based on the Lennard-Jones Potential

2016 ◽  
Author(s):  
Hiroshige Matsuoka ◽  
Teppei Tanaka ◽  
Ryoya Miyake ◽  
Shigehisa Fukui
Keyword(s):  
Half Space ◽  
Material Distribution ◽  
Elementary Functions ◽  
Jones Potential ◽  
One Dimensional ◽  
Single Interface ◽  
Periodic Distribution ◽  
Lennard Jones ◽  
Plane Direction ◽  
Basic Characteristics

The interaction stresses acting between a half-space consisting of a uniform material and a half-space with a one-dimensional material distribution in the in-plane direction have been derived. Two patterns of the material distribution are considered: a periodic distribution of materials (Pattern 1) and a distribution of two materials with a single interface (Pattern 2). The interaction stresses for Pattern 1 were derived using a Fourier series, while the interaction stresses for Pattern 2 were derived as elementary functions. The basic characteristics of these interaction stresses were clarified.

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