scholarly journals The effect of heat transfer on the stress-strain material state considering the final rate of heat spread

2021 ◽  
Vol 1901 (1) ◽  
pp. 012122
Author(s):  
N E Proskuriakov ◽  
I V Lopa ◽  
I V Zverev
Keyword(s):  
Heat Transfer ◽  
Stress Strain ◽  
Material State

Liquid-Metal-Bath Stress-Strain Apparatus

1965 ◽  
Vol 38 (4) ◽  
pp. 782-790
Author(s):  
G. L. Hall ◽  
J. D. Rigby ◽  
J. W. Liska
Keyword(s):  
Heat Transfer ◽  
Atmospheric Oxygen ◽  
Uniform Temperature ◽  
Metal Bath ◽  
Stress Strain ◽  
Temperature Resistance ◽  
Rubber Compounds ◽  
Liquid Metal Bath ◽  
Base Polymer ◽  
Heating Medium

Abstract A simple, reliable apparatus for measuring stress-strain properties of vulcanizates at temperatures up to at least 800° F has been developed. The heating medium is a molten metal bath which provides uniform temperature distribution and rapid heat transfer while excluding atmospheric oxygen. Ultimate tensile strengths are in excellent agreement with those obtained in conventional air-oven tests. Stress relaxation tests show the effects of excluding atmospheric oxygen from the specimens. Somewhat higher ultimate elongations are obtained in the liquid-bath than in air-oven apparatus, for which possible reasons are suggested. Results on vulcanizates of heat-resistant polymers demonstrate that retention of physical properties at 500° F or 600° F cannot be safely predicted from data obtained at 400° F. The curing system, as well as the base polymer, is very important to high temperature resistance. In both Diene and butyl rubber compounds, for example, resin cures were superior in this respect to more conventional curing systems.

Concurrent simulation of multibody systems coupled with stress–strain and heat transfer solvers

2012 ◽  
Vol 3 (6) ◽  
pp. 492-497 ◽  
Author(s):  
Victor V. Getmanskiy ◽  
Alexander S. Gorobtsov ◽  
Efim S. Sergeev ◽  
Timur D. Ismailov ◽  
Oleg V. Shapovalov
Keyword(s):  
Heat Transfer ◽  
Multibody Systems ◽  
Stress Strain ◽  
Concurrent Simulation

Study on LCF Lifetime Prediction of Thermal Shock

2012 ◽  
Vol 152-154 ◽  
pp. 924-930
Author(s):  
Wei Mao Zhao ◽  
Wei Zheng Zhang ◽  
Zhao Ju Qin
Keyword(s):  
Heat Transfer ◽  
Thermal Shock ◽  
Energy Method ◽  
Heated Surface ◽  
Dissipated Energy ◽  
Stress Strain ◽  
Fixed Temperature ◽  
Cooling Temperature ◽  
Cooling Speed ◽  
Cyclic Heat

Gray cast iron specimen was heated to a fixed temperature with high frequency induction heating equipment, then was cooled to room temperature by spraying water to the heated surface. This process was repeated until a crack whose length exceeds 3mm appeared. Transient cyclic heat transfer and stress-strain FEA analysis was conducted to obtain specimen’s stress-strain state, then different LCF life prediction methods based on strain and energy were presented and contrasted, and results showed modified dissipated energy method with maximal hydrostatic pressure was more accurate than other methods. With the help of modified dissipated energy method, the relationship between thermal shock life, highest cooling temperature and cooling speed was studied, and the effect law of highest cooling temperature and cooling heat transfer coefficient on life was obtained.

Fatigue Life Prediction in Rapid Die Casting

2008 ◽  
Author(s):  
Chuan Huat Ng ◽  
Karl-Heinrich Grote ◽  
Ru¨diger Ba¨hr
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Fatigue Life ◽  
Experimental Testing ◽  
Die Casting ◽  
Life Time ◽  
Casting Process ◽  
Simulation Software ◽  
Stress Strain ◽  
Fracture Models

During a die casting process, it is very difficult to achieve efficient and correct casting tooling endurance results by the casting designer and foundry man. However, it is very costly and time consuming to predict the tooling endurance with a trial and error method based on expertise and experience. After an extensive fatigue design study, it was possible to develop specimen design models for the simulation of the time and temperature dependent stress-strain and fracture models to determine the thermal fatigue prediction. In this research, stress-strain approach, heat transfer concept and life time calculation methods were used to predict the casting tool endurance by a computer simulation. The thermal stress and heat transfer behaviour analysis were performed using RWP casting numerical simulation software. It is shown that numerical simulation techniques can simulate stress concentration on the specimen surface to thermal behaviour. Furthermore, the result from the specimen based simulation model associated with fracture indicators permits the construction of a life time design curve independent of time and temperature. The fatigue life predicted by simulation based models and the results from experimental testing on real components are very similar. The simulation results showed that they match the experimental results, including a design safety factor.

EFFECT OF HEAT TRANSFER ON THE STRESS-STRAIN STATE OF THE MATERIAL CONSIDERING THE FINAL HEAT PROPAGATION VELOCITY

2021 ◽  
Author(s):  
N. E. Proskuriakov ◽  
◽  
I. V. Lopa ◽  
Keyword(s):  
Heat Transfer ◽  
Propagation Velocity ◽  
Strain State ◽  
Heat Propagation ◽  
Stress Strain ◽  
Final Heat ◽  
Stress Strain State

Анализируются результаты расчетов различных волновых задач. Показано, что деформационный нагрев материала интенсивен вблизи граничной поверхности и быстро уменьшается при незначительном удалении от нее. Делается вывод, что для получения точных решений волновых задач в неизотермической постановке необходимо учитывать перераспределение температуры в материалах из-за теплопередачи и его влияние на напряженно-деформированное состояние материалов различных конструкций. Приводятся результаты расчетов. Отмечена чувствительность решения к изменению удельной теплоемкости и коэффициента температуропроводности, входящих в волновое уравнение теплопроводности.

Thermodynamically Consistent Thermomechanical Modeling of Kinetics of Macroscopic Phase Transition in SMA Using Phase Field Theory

2014 ◽  
Author(s):  
Babatunde O. Agboola ◽  
Theocharis Baxevanis ◽  
Dimitris C. Lagoudas
Keyword(s):  
Heat Transfer ◽  
Phase Transition ◽  
Inelastic Strain ◽  
Thermomechanical Coupling ◽  
Macroscopic Model ◽  
Configurational Forces ◽  
External Loading ◽  
Strain Response ◽  
Stress Strain ◽  
Kinetics Of

Experimental observations have shown that polycrystalline NiTi wires, strips and tubes develop inelastic strain via nucleation and growth of macroscopic martensitic domains under mechanical loading. These domains consist of almost fully-transformed grains, which result from micro-domains that are formed at the grain-size level. Evolution of these macroscopic domains via transformation front propagation is accompanied by complex interactions between mechanical work, latent heat, heat transfer, and loading rates. These interactions could affect the performance reliability or controllability of the material when deployed. Therefore, modeling effort is necessary to describe these interactions so as to improve the design and application of SMA devices. A 3-D thermodynamically consistent thermomechanical macroscopic model, which is able to describe phase transition kinetics in shape memory alloys, is proposed in this work. The model employs a Ginzburg-Landau-type kinetic law resulting from the notion of configurational forces associated with the gradient of an order parameter (a field variable). As a first attempt to demonstrate the capability of the model, 1-D simplification of the model is implemented within a finite element framework. Kinetics of phase transition and the effects of heat production associated with the thermomechanical coupling on the stress-strain response of an SMA are examined. In particular, the roles of external loading rate and heat transfer boundary conditions on the stress-strain response are investigated for displacement-controlled loading. Results obtained are in good agreement with experimental trends.

scholarly journals The study of heat transfer and stress-strain state of a material, taking into account its fractal structure

2020 ◽  
Vol 7 (2) ◽  
pp. 400-409
Author(s):  
Ya. I. Sokolovskyy ◽  
◽  
M. V. Levkovych ◽  
I. Ya. Sokolovskyy ◽  
◽  
...  
Keyword(s):  
Heat Transfer ◽  
Strain State ◽  
Fractal Structure ◽  
Stress Strain ◽  
Stress Strain State

Life Prediction Based on Material State Changes in Ceramic Matrix Composite Materials

2007 ◽  
Author(s):  
Ken Reifsnider ◽  
S. W. Case
Keyword(s):  
High Temperature ◽  
Composite Materials ◽  
Gas Turbines ◽  
Ceramic Composite ◽  
Ceramic Matrix Composite ◽  
Ceramic Composites ◽  
Stress Strain ◽  
Material State ◽  
State Changes ◽  
Ceramic Composite Materials

Monolithic ceramics and continuous fiber reinforced ceramic composites are being developed for use in high temperature applications such as combustor liners in gas turbines, thrust deflectors for jet engines, and thruster nozzles. Ceramic composite materials possess the high temperature resistance properties of ceramics, but have better creep and cyclic properties. However, the properties of these materials change somewhat with time at service temperatures, i.e., their material state changes as a function of service conditions and history. The authors have developed a methodology for representing and combining the effects of high temperature material state changes in CMCs, along with changes in applied stress / strain conditions during service, to estimate remaining strength and life of ceramic composite materials and components. Fatigue, creep rupture, and time dependent deformation are combined by a strength metric in integral form to create a time-resolved, point-wise estimate of current remaining strength and life in material elements. Application of this methodology in discrete element representations of mechanical behavior of structural elements with nonuniform stress / strain states has been implemented.

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