Cracking Response of a Concrete Wall to Cryogenic Temperature

2015 ◽  
Vol 365 ◽  
pp. 71-76
Author(s):  
Lahlou Dahmani ◽  
Rabah Hammar ◽  
Mohamed Oussalem Mechiche
Keyword(s):  
Cryogenic Temperature ◽  
Heat Conduction Problem ◽  
Outer Wall ◽  
Distribution Data ◽  
Cryogenic Temperatures ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Concrete Wall ◽  
Steel Tank ◽  
Concrete Tank

Liquefied natural gas (LNG) has the cryogenic temperature of –160°C to ensure the minimum storage volume when stored in LNG containers. Among various types of LNG storage containers, the full containment above-ground type with a double safety system (outer concrete tank and inner steel tank) is very common. Normally, the inner tank contains LNG, but when the LNG leaks from the inner tank, the outer concrete tank comes into contact with LNG. Under this accidental case, it is indispensable for the outer wall to keep the liquid tightness in order to safely contain the LNG before taking any countermeasure. It is, therefore, proposed to take up a heat conduction problem using the finite element method with the ANSYS software to obtain temperature distribution data of a concrete wall at cryogenic temperatures.

Thermomecanical Response of LNG Concrete Tank to Cryogenic Temperatures

2011 ◽  
Vol 312-315 ◽  
pp. 1021-1026 ◽  
Author(s):  
Lahlou Dahmani ◽  
Rachid Mehaddene
Keyword(s):  
Numerical Evaluation ◽  
Thermal Stresses ◽  
Liquefied Natural Gas ◽  
Field Analysis ◽  
Distribution Data ◽  
Cryogenic Temperatures ◽  
Heat Temperature ◽  
Coupled Field ◽  
Concrete Tank ◽  
Transient Thermal

In this paper are illustrated the principal aspects connected with the numerical evaluation of thermal stress induced by LNG (liquefied natural gas) in a concrete tank. In order to investigate the thermal induced tensile stresses, the ANSYS finite element code has been employed for performing a sequential, non linear, transient thermal-structural analysis, taking into account the thermal dependant properties of the concrete such as thermal conductivity and specific heat. Temperature distribution data of thermal analysis is required in the coupled field analysis finally to obtain and analyze thermal stresses.

Analysis of Hydroelectric Unit’s Upper Bracket Based on Test and FEM

2014 ◽  
Vol 721 ◽  
pp. 131-134
Author(s):  
Mi Mi Xia ◽  
Yong Gang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Element Model ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Element Analysis ◽  
Hydroelectric Unit ◽  
The Finite Element Analysis ◽  
Strain Rosette ◽  
The Finite Element Model

To research the load upper bracket of Francis hydroelectric unit, then established the finite-element model, and analyzed the structure stress of 7 operating condition points with the ANSYS software. By the strain rosette test, acquired the data of stress-strain in the area of stress concentration of the upper bracket. The inaccuracy was considered below 5% by analyzing the contradistinction between the finite-element analysis and the test, and match the engineering precision and the test was reliable. The finite-element method could be used to judge the stress of the upper bracket, and it could provide reference for the Structural optimization and improvement too.

scholarly journals Influence of Fins Number and Frosting on Heat Transfer through Longitudinal Finned Tubes of LNG Ambient Air Vaporizers

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 280
Author(s):  
Filip Lisowski ◽  
Edward Lisowski
Keyword(s):  
Power Supply ◽  
Cryogenic Temperature ◽  
Analytical Approach ◽  
Unit Length ◽  
Heat Rate ◽  
Ambient Air ◽  
Finned Tube ◽  
Ansys Software ◽  
Finned Tubes ◽  
Gaseous Form

The use of cryogenic liquefied gasses in industry is constantly increasing both for process purposes and for power supply needs. The liquefied natural gas (LNG) is stored at cryogenic temperature and its immediate use in gaseous form requires its evaporation. The heat needed to cause a phase change is usually delivered by means of vaporizers. This paper presents a numerical analysis of the influence of the fins number and frost accumulated within the fins surface on the heat transferred through the aluminum finned tubes of LNG ambient air vaporizers. The calculations were carried out applying finite element thermal analysis within Ansys software as well as using an analytical approach. As a result, the heat rate per unit length of the finned tube was obtained. The results were compared for different numbers of longitudinal fins both without frost and for total frosting of the tubes.

scholarly journals A 1D Model for Predicting Heat and Moisture Transfer through a Hemp-Concrete Wall Using the Finite-Element Method

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6903
Author(s):  
Maroua Benkhaled ◽  
Salah-Eddine Ouldboukhitine ◽  
Amer Bakkour ◽  
Sofiane Amziane
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Moisture Transfer ◽  
Construction Material ◽  
Climatic Conditions ◽  
Vapor Permeability ◽  
Transfer Model ◽  
The Finite Element Method ◽  
Concrete Wall ◽  
Element Method

Plant-based concrete is a construction material which, in addition to having a very low environmental impact, exhibits excellent hygrothermal comfort properties. It is a material which is, as yet, relatively unknown to engineers in the field. Therefore, an important step is to implement reliable mass-transfer simulation methods. This will make the material easy to model, and facilitate project design to deliver suitable climatic conditions. In recent decades, numerous studies have been carried out to develop models of the coupled transfers of heat, air and moisture in porous building envelopes. Most previous models are based on Luikov’s theory, considering mass accumulation, air and total pressure gradient. This theory considers the porous medium to be homogeneous, and therefore allows for hygrothermal transfer equations on the basis of the fundamental principles of thermodynamics. This study presents a methodology for solving the classical 1D (one-dimensional) HAM (heat, air, and moisture) hygrothermal transfer model with an implementation in MATLAB. The resolution uses a discretization of the problem according to the finite-element method. The detailed solution has been tested on a plant-based concrete. The energy and mass balances are expressed using measurable transfer quantities (temperature, water content, vapor pressure, etc.) and coefficients expressly related to the macroscopic properties of the plant-based concrete (thermal conductivity, specific heat, water vapor permeability, etc.), determined experimentally. To ensure this approach is effective, the methodology is validated on a test case. The results show that the methodology is robust in handling a rationalization of the model whose parameters are not ranked and not studied by their degree of importance.

scholarly journals Finite element analysis of microclimate parameters in the metallurgical crane cabin

2021 ◽  
pp. 10-20
Author(s):  
V. V. Maslenskiy ◽  
◽  
Yu. I. Bulygin ◽  
Keyword(s):  
Finite Element ◽  
Air Conditioning ◽  
Engineering Calculation ◽  
Air Pressure ◽  
The Finite Element Method ◽  
Air Flow Rate ◽  
Ansys Software ◽  
Element Analysis ◽  
Air Conditioning System ◽  
Characteristic Points

Introduction. The article analyzes the microclimate parameters (temperature, speed and air pressure) in the metallurgical crane cabin provided by the air conditioning system using the finite element method integrated into the ANSYS software package. The metallurgical crane cabin air conditioning system was selected based on the engineering calculation of the required air flow rate supply, taking into account factors that affect the system performance, such as the location of the equipment and the degree of its dustiness. Problem Statement. The purpose of this research was to check the efficiency of the air conditioning system of the metallurgical crane cabin, which was selected based on the results of the engineering calculations. Theoretical Part. In the main part of the research, the distribution fields of temperature, speed and air pressure inside the cabin of a metallurgical crane were constructed, the values at the points of which were compared with the hygienic standards. In addition, the factors that affect the adequacy of the developed model were considered, namely the grid structure, the way to set the initial and boundary conditions. Conclusion. The refinement of the analysis grid and the consideration of infiltration in the model eventually allowed us to get more correct results: the temperature at the characteristic points differ by no more than 1.3 °C, the speed values do not exceed the standard 0.3 m/s, the average normalized temperature of 24 °C is maintained in a volume of about 60-70 % of the total cabin volume.

scholarly journals Ansys code applied to investigate the dynamics of composite sandwich beams

2021 ◽  
Vol 25 (1) ◽  
pp. 62-71
Author(s):  
Agnieszka Chudzik
Keyword(s):  
Sandwich Beam ◽  
Strength Properties ◽  
Effect Of Temperature ◽  
Material Strength ◽  
Beam Model ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Composite Sandwich ◽  
Viscoelastic Core ◽  
Influence Of Temperature On

Abstract A numerical analysis of the effect of temperature on the dynamics of the sandwich beam model with a viscoelastic core is presented. The beam under analysis was described with a standard rheological model. This solution allows one to study the effect of temperature on material strength properties. Calculations were performed with the Finite Element Method in the ANSYS software. The analysis of the results of the numerical calculations showed a significant influence of temperature on the strength properties of the model under test. The analysis confirmed damping properties of viscoelastic materials.

scholarly journals The Influence of PZT Actuators Positioning in Active Structural Acoustic Control

10.14311/968 ◽  
2007 ◽  
Vol 47 (4-5) ◽  
Author(s):  
P. Švec ◽  
V. Jandák
Keyword(s):  
Sound Field ◽  
Structural Vibration ◽  
Structural Acoustics ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Structural Vibrations ◽  
Radiated Power ◽  
Acoustic Control ◽  
Radiated Sound ◽  
The Mathematical Model

This paper deals with the effect of secondary actuator positioning in an active structural acoustics control (ASAC) experiment. The ASAC approach is based on minimizing the sound radiation from structures to the far field by controlling the structural vibrations. In this article a rectangular steel plate structure was assumed with one secondary actuator attached to it. As a secondary actuator, a specially designed piezoelectric stripe actuator was used. We studied the effect of the position of the actuator on the pattern and on the radiated sound field of the structural vibration, with and without active control. The total radiated power was also measured. The experimental data was confronted with the results obtained by a numerical solution of the mathematical model used. For the solution, the finite element method in the ANSYS software package was used. 

Cryogenic Temperature Dependence of the Yield Strength of High-Strength Alloys

1966 ◽  
Vol 88 (1) ◽  
pp. 117-128 ◽  
Author(s):  
C. T. Yang
Keyword(s):  
Yield Strength ◽  
Stainless Steels ◽  
General Equation ◽  
Cryogenic Temperature ◽  
Elevated Temperatures ◽  
High Strength ◽  
Cryogenic Temperatures ◽  
Test Range ◽  
Titanium Nickel ◽  
Straight Lines

The effect of cryogenic temperatures (from 78 F to −423 F) on the yield strength of twenty alloys was studied. Experimental results prove that they do not conform to any of the following theories: Hollomon and Zener’s, Cottrell and Bilby’s, or Fisher’s. However, all the plottings in loge-loge scale of yield strength versus absolute cryogenic temperatures of these alloys fall on straight lines which are governed by one single general equation, σy = bT−m. From the Cottrell’s dislocation theory on yielding and Fisher’s equation of activation energy in forming a dislocation loop, the same type of equation of yield strength versus temperature as expressed by the empirical ones can be derived theoretically. The empirical equations are very useful in predicting yield strengths at any cryogenic temperature within or slightly out of the test range for which data were available. Some limited yield strength data at elevated temperatures for a few alloys were studied for comparison. It was observed the general equation for yield strength versus cryogenic temperatures holds valid for stainless steels but not so well for titanium, nickel, and aluminum alloys at elevated temperatures. However, no conclusion can be drawn until further detailed studies at elevated temperatures are made.

scholarly journals Features of compressed rods calculations with account of initial imperfections and creep effects

2020 ◽  
Vol 164 ◽  
pp. 02003
Author(s):  
Viacheslav Chepurnenko ◽  
Batyr Yazyev ◽  
Ludmila Dubovitskaya
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Software Package ◽  
Physical Nonlinearity ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Modular Theory ◽  
Initial Imperfections ◽  
Creep Models ◽  
The Finite Difference Method

The article presents solutions to the problem of rod buckling, taking into account creep effects. Trigonometric series, the finite difference method in combination with the programming language MATLAB, as well as the finite element method in the ANSYS software package were used in the solutions. The behavior of the rods is researched for two types of relations between strain and stress during creep, with strains in an explicit and implicit form. When solving, the criterion of initial imperfections with their different values is used, as well as the tangential-modular theory. The results obtained for the two creep models are compared. The conclusion is made about the accuracy of the results of calculations in ANSYS with the presence of a combination of geometric and physical nonlinearity for various creep models.

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