Two Approaches to the Study of Temperature Effect on the Dissipative Properties of Materials

2022 ◽  
Vol 906 ◽  
pp. 69-76
Author(s):  
Tigran Petrosyan
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Effect Of Temperature ◽  
Energy Losses ◽  
Temperature Function ◽  
Temperature Changes ◽  
Different Temperatures ◽  
Theory Equation ◽  
Instantaneous Deformation ◽  
Properties Of Materials

In order to study the effect of temperature changes on the dissipative properties of materials, two approaches are used. The first approach implies introducing some temperature function under the sign of the integral in the heredity theory equation and simultaneously taking into account the dependence of the elastic modulus on temperature. As a result, based on experimental data on the thermal creep of soils, the expression for determining the hysteresis energy losses under the periodic voltage changes was obtained depending on temperature changes.According to the second approach, the expression for determining the hysteresis energy losses under isothermal conditions at different temperatures was obtained by introducing into the heredity theory equation an approximation of the experimental dependences of instantaneous deformation and temperature creep parameters for steel Kh18 N10T.

Effect Of Elevated Temperatures On Complete Concrete Deformation Diagrams

2019 ◽  
pp. 9-14
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Elevated Temperatures ◽  
Peak Load ◽  
Relative Deformation ◽  
Deformation Characteristics ◽  
Compression Tests ◽  
Strain Behavior ◽  
Different Temperatures ◽  
Deformation Diagrams

The analysis of the previous results of the study on concrete stress-strain behavior at elevated temperatures has been carried out. Based on the analysis, the main reasons for strength retrogression and elastic modulus reduction of concrete have been identified. Despite a significant amount of research in this area, there is a large spread in experimental data received, both as a result of compression and tension. In addition, the deformation characteristics of concrete are insufficiently studied: the coefficient of transverse deformation, the limiting relative compression deformation corresponding to the peak load and the almost complete absence of studies of complete deformation diagrams at elevated temperatures. The two testing chambers provided creating the necessary temperature conditions for conducting studies under bending compression and tension have been developed. On the basis of the obtained experimental data of physical and mechanical characteristics of concrete at different temperatures under conditions of axial compression and tensile bending, conclusions about the nature of changes in strength and deformation characteristics have been drawn. Compression tests conducted following the method of concrete deformation complete curves provided obtaining diagrams not only at normal temperature, but also at elevated temperature. Based on the experimental results, dependences of changes in prism strength and elastic modulus as well as an equation for determining the relative deformation and stresses at elevated temperatures at all stages of concrete deterioration have been suggested.

A Study on the Effect of the Temperature on Mechanical Properties of H90 Copper Strip

2019 ◽  
Vol 950 ◽  
pp. 65-69
Author(s):  
Sun Fei ◽  
Xu Cheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Effect Of Temperature ◽  
Basic Material ◽  
Copper Strip ◽  
Study Results ◽  
Different Temperatures ◽  
Strip Test

In order to study the effect of temperature on the mechanical properties of H90 copper strip material, the H90 copper strip test pieces were heated to different temperatures (20~600 °C) for tensile test; the yield strength, tensile strength, elastic modulus and elongation of H90 copper strip at different temperatures were obtained. Based on the test results, the empirical models of yield strength, tensile strength, elastic modulus of H90 copper strip at high temperature were established; the test showed that, with the increase of temperature, the yield strength, tensile strength and elastic modulus of H90 copper strip decreased greatly, and the elongation after fracture first increased-decreased-increased at 20~600 °C. The study results in this paper provide basic material data for analyzing the effect of temperature on the continuous firing of firearms and other weapons.

scholarly journals Effect of Temperature and Electrical Modes on Radiation Sensitivity of MISFET Dose Sensors

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 954 ◽  
Author(s):  
Boris Podlepetsky ◽  
Viacheslav Pershenkov ◽  
Alexander Bakerenkov ◽  
Vladislav Felitsyn ◽  
Alexander Rodin
Keyword(s):  
Experimental Data ◽  
Gate Voltage ◽  
Drain Current ◽  
Radiation Sensitivity ◽  
Effect Of Temperature ◽  
Conversion Function ◽  
Radiation Doses ◽  
Total Ionizing Dose ◽  
Different Temperatures ◽  
Source Voltage

The temperature and electrical modes influences on radiation sensitivity of n-channel MISFETs sensors of the total ionizing dose were investigated. There were measured the MISFET-based dosimeter output voltages V as function of the radiation doses D at const values of the drain current ID and the drain–source voltage VD, as well as the (ID–VG) characteristics before, during and after irradiations at different temperatures T (VG is the gate voltage). It was shown how the conversion function V(D) and the radiation sensitivity SD are depending on the temperature T for different electrical modes. To interpret experimental data there were proposed the models taking into account the separate contributions of charges in the dielectric Qt and in SiO2–Si interface Qs. The model’s parameters ΔVt(D,T) and ΔVs(D,T) were calculated using the experimental ID–VG characteristics. These models can be used to predict performances of MISFET-based devices.

Energy losses due to routine and feeding metabolism in young-of-the-year juvenile Atlantic cod (Gadus morhua)

2003 ◽  
Vol 60 (8) ◽  
pp. 929-937 ◽  
Author(s):  
Myron A Peck ◽  
Lawrence J Buckley ◽  
David A Bengtson
Keyword(s):  
Body Size ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Effect Of Temperature ◽  
Energy Losses ◽  
The North ◽  
A Value ◽  
Different Temperatures ◽  
Body Sizes ◽  
Environmental Temperatures

We examined the effects of body size (3–13 cm total length) and temperature (4.5, 8.0, 12.0, and 15.5 °C) on routine (RR) and feeding (RSDA) energy losses by laboratory-reared, young-of-year juvenile Atlantic cod (Gadus morhua). The magnitude of the effect of temperature on RR, expressed via the Q10, was nonlinear. Q10 values were greatest at temperatures between 4.5 and 8.0 °C and were lowest between 8.0 and 15.5 °C, with larger fish tending to exhibit the greatest change in RR irrespective of the temperature combination. Energy losses resulting from RSDA were ~4% of consumed energy, a value less than half that estimated for larger, year-1+ juvenile cod fed similar-sized rations. Data from this and other studies were combined to generate an equation estimating routine energy loss at different temperatures and body sizes for cod. The equation describes RR over the eight orders of magnitude difference in body size from young larvae to adults within a range of environmental temperatures experienced by this species on Georges Bank and other areas in the North Atlantic.

scholarly journals Study of the Effect of Temperature Changes on the Elastic Modulus of Flexible Pavement Layers

2013 ◽  
Vol 5 (5) ◽  
pp. 1661-1667 ◽  
Author(s):  
Mohd Raihan Taha ◽  
Sentot Hardwiyono ◽  
Nur Izzi Md. Yusoff ◽  
Mohd Rosli Hainin ◽  
Jiantao Wu ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Flexible Pavement ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Pavement Layers

5-hydroxymethyl furfural formation and reaction kinetics of different pekmez samples: effect of temperature and storage

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Rasim Alper Oral ◽  
Mahmut Dogan ◽  
Kemal Sarioglu ◽  
Ömer Said Toker
Keyword(s):  
Reaction Kinetics ◽  
Arrhenius Equation ◽  
Storage Period ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Juniperus Communis ◽  
Hydroxymethyl Furfural ◽  
Different Temperatures ◽  
And Storage ◽  
Kinetics Of

Abstract Pekmez (molasses) is a traditional food commonly produced from grape and other kind of fruit juices by evaporation processes. In this study, 5-Hydroxymethylfurfural (HMF) level of various pekmez samples was investigated during storage at different temperatures. HMF content of apricot, mulberry, carob, grape, Juniperus communis pekmez changed from 133.0 ppm to 1060.5 ppm, from 88.2 to 1921.5 ppm, from 11.1 to 1153.6 ppm, from 75.5 to 2077.0 ppm, from 19.9 to 280.1 ppm throughout eight months storage period, respectively. Samples of pekmez from the Juniperus communis had the minimum k values for each temperature that means HMF formation in these samples were slower than other pekmez types. The kinetic data analysis for HMF formation during storage was performed and an Arrhenius equation was used to determine the effect of temperature on reaction kinetics of 5-HMF formation in pekmez samples. Ea values were found between 10.58–37.73 (kcal/mol). Apricot pekmez was found as the least sensitive sample to HMF formation resulted from temperature changes.

Deployment Analysis of Deployable Structures Based on Linkages Considering Thermal Effect

2013 ◽  
Author(s):  
Jian-guo Cai ◽  
Jian Feng ◽  
Yao-zong Zhao
Keyword(s):  
Thermal Loading ◽  
Dynamic Performance ◽  
Space Environment ◽  
Effect Of Temperature ◽  
Deployable Structures ◽  
Temperature Changes ◽  
Different Temperatures ◽  
Internal Forces ◽  
Space Environments ◽  
Four Bar Linkage

The thermal stress due to temperature rise may increase the element strain and internal forces, which may lead to the failure of the deployment of deployable structure. However, few works are carried out to study the dynamic performance of the flexible multibody under different temperatures, especially for deployable structures that work in space environments. Based on this idea and formulation of finite element methods, the dynamic equations of the system considering the temperature effect are derived. Then two examples, a parallel four-bar linkage and a non-parallel four-bar linkage, are presented in this paper to study the influence of thermal loading on the structural behavior during the motion. The results show that the effect of temperature changes is slight for the parallel four-bar linkage, but the influence is significant for the non parallel four-bar linkage. It can be concluded that the former case may be more suitable for the deployable structures in space environment.

Rolling Resistance Calculation Procedure Using the Finite Element Method

2019 ◽  
Vol 48 (3) ◽  
pp. 224-248
Author(s):  
Pablo N. Zitelli ◽  
Gabriel N. Curtosi ◽  
Jorge Kuster
Keyword(s):  
Finite Element ◽  
Energy Dissipation ◽  
Rolling Resistance ◽  
Element Model ◽  
The Finite Element Method ◽  
Temperature Changes ◽  
Rubber Compounds ◽  
Different Temperatures ◽  
Materials Used ◽  
Account Temperature

ABSTRACT Tire engineers are interested in predicting rolling resistance using tools such as numerical simulation and tests. When a car is driven along, its tires are subjected to repeated deformation, leading to energy dissipation as heat. Each point of a loaded tire is deformed as the tire completes a revolution. Most energy dissipation comes from the cyclic loading of the tire, which causes the rolling resistance in addition to the friction force in the contact patch between the tire and road. Rolling resistance mainly depends on the dissipation of viscoelastic energy of the rubber materials used to manufacture the tires. To obtain a good rolling resistance, the calculation method of the tire finite element model must take into account temperature changes. It is mandatory to calibrate all of the rubber compounds of the tire at different temperatures and strain frequencies. Linear viscoelasticity is used to model the materials properties and is found to be a suitable approach to tackle energy dissipation due to hysteresis for rolling resistance calculation.

Consideration of the temperature factor of atmospheric air when determining standard consumption of fuel and energy resources for train traction

2018 ◽  
Vol 77 (6) ◽  
pp. 375-381
Author(s):  
K. M. Popov
Keyword(s):  
Statistical Processing ◽  
Specific Consumption ◽  
Energy Resources ◽  
Effect Of Temperature ◽  
Influence Coefficient ◽  
Specific Work ◽  
Specific Flow ◽  
Temperature Changes ◽  
Work Area ◽  
Physical Laws

Abstract. Influence of air temperature on the consumption of fuel and energy resources (FER) on train traction is due to a number of physical laws. The extent of this effect is specified in the Rules for Traction Settlement (RTS). At the same time, when rationing FER consumption for train traction, a specialized methodical base is used, which involves a different approach to accounting for the effect of temperature on FER consumption for train traction. At the same time in different documents of this base, the effects of low temperature on the absolute and specific consumption of fuel and energy resources on train traction are taken into account in a different way, which is due to the lack of consensus among specialists on the way this factor is taken into account. Specialists of JSC “VNIIZhT” carried out an analysis of a significant amount of driver’s routes data, results of which showed that the dependence of the specific flow rate on temperature, on the basis of which the corresponding influence coefficient is determined, needs to be periodically updated. In addition, when technically standardizing the consumption of fuel and energy resources (for the locomotive crew work site), the temperature effect coefficients need to be calculated for a specific work area and direction of motion on it, while using the average network coefficient values will lead to errors. When calculating additional flow of fuel and energy from the effect of temperature for electric multiple units (EMU), the equations of regression dependencies should be used, obtained by statistical processing of data on temperature changes and specific consumption of fuel and energy resources for EMU and determined for each series of EMU when working on a particular suburban area.

Modelling of catalyst pellet deactivation

1985 ◽  
Vol 50 (11) ◽  
pp. 2381-2395
Author(s):  
Alena Brunovská ◽  
Ján Buriánek ◽  
Ján Ilavský ◽  
Ján Valtýni
Keyword(s):  
Experimental Data ◽  
Numerical Results ◽  
Benzene Hydrogenation ◽  
Alumina Catalyst ◽  
Temperature Changes ◽  
Catalyst Pellet ◽  
Model Equations ◽  
Catalytic Poison

The diffusion and the shell progressive models of deactivation caused by irreversible chemisorption of a catalytic poison are presented for a single catalyst pellet. The method for solution of the model equations is proposed. The numerical results are compared with experimental data obtained by measuring concentration and temperature changes due to thiophene poisoning in benzene hydrogenation over a nickel-alumina catalyst.

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