Determination of the Self-Heating Temperature of Coal by Means of TGA Analysis

2018 ◽  
Vol 32 (2) ◽  
pp. 2299-2305 ◽  
Author(s):  
Jale Naktiyok
Keyword(s):  
Heating Temperature ◽  
The Self ◽  
Self Heating ◽  
Tga Analysis

scholarly journals Stationary Self-Heating of the Circular and Annular Composite Plates Hinged on the Boundary under Axisymmetric Cyclic Loading

2011 ◽  
Vol 20 (5) ◽  
pp. 096369351102000 ◽  
Author(s):  
Andrzej Katunin
Keyword(s):  
Heat Transfer ◽  
Cyclic Loading ◽  
Transfer Equation ◽  
Heating Temperature ◽  
Composite Plates ◽  
The Self ◽  
Heat Transfer Equation ◽  
Dissipation Energy ◽  
Self Heating ◽  
Parametric Analyses

The present study is focused on the analytical modelling of the stationary self-heating caused by the hysteretic behaviour of the polymeric laminated circular and annular plates hinged on the boundary under axisymmetric transverse cyclic loading. The investigation was based on the complex parameters concept. The coupled thermoviscoelasticity problem was solved by substitution of the dissipation energy function to the heat transfer equation as a source function. The self-heating temperature distributions formulas were obtained by solving the heat transfer equation with appropriate thermal boundary conditions using trigonometric Fourier series. Numerous parametric analyses were presented. It was shown, that omitting the influence of the self-heating effect may results in the incorrect description of the behaviour of polymeric composites under cyclic loading.

scholarly journals Rapid determination of the high cycle fatigue properties of high temperature aeronautical alloys by self-heating measurements

2018 ◽  
Vol 165 ◽  
pp. 22022
Author(s):  
Vincent Roué ◽  
Cédric Doudard ◽  
Sylvain Calloch ◽  
Frédéric Montel ◽  
Quentin Pujol D’Andrebo ◽  
...  
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
High Cycle Fatigue ◽  
Rapid Determination ◽  
The Self ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Heating Method ◽  
Self Heating

The determination of high cycle fatigue (HCF) properties of a material with standard method requires a lot of specimens, and could be really time consuming. The self-heating method has been developed in order to predict S–N–P curves (i.e., amplitude stress – number of cycles to failure – probability of failure) with only a few specimens. So the time-saving advantage of this method has been demonstrated on several materials, at room temperature. In order to reduce the cost and time of fatigue characterization at high temperature, the self-heating method is adapted to characterize HCF properties of a titanium alloy, the Ti-6Al-4V (TA6V), at different temperatures. So the self-heating procedure is adjusted to conduct tests with a furnace. Two dissipative phenomena can be observed on self-heating curves. Because of this, a two-scale probabilistic model with two dissipative mechanisms is used to describe them. The first one is observed for low amplitudes of cyclic loading, under the fatigue limit, and the second one for higher amplitudes where the mechanisms of fatigue damage are activated and are dissipating more energy. This model was developed on steel at room temperature. Even so, it is used to describe the self-heating curves of the TA6V at several temperatures.

scholarly journals Fatigue and Thermal Failure of Polymeric Composites Subjected to Cyclic Loading

2012 ◽  
Vol 21 (3) ◽  
pp. 096369351202100 ◽  
Author(s):  
Andrzej Katunin ◽  
Marek Fidali
Keyword(s):  
Cyclic Loading ◽  
Heating Temperature ◽  
Qualitative Evaluation ◽  
Polymeric Composites ◽  
The Self ◽  
Heating Effect ◽  
Thermal Failure ◽  
Self Heating ◽  
Measurement Results ◽  
Parametric Dependencies

In the presented study the experimental results for the investigation of fatigue of polymeric composites subjected to intensive cyclic loading with presence of the self-heating effect were presented. Experiments were carried out on laboratory stand, which provides the synchronous measurement of loading force, displacements and temperature. It was observed, that the fatigue process during occurrence of the self-heating effect consists of three phases, which were analyzed and described. The characteristic self-heating temperature distributions and their evolution during the whole loading history were analyzed. The parametric analysis of influence of loading conditions on the self-heating temperature evolution and fatigue of polymeric composites was presented. Basing upon the measurement results the authors proposed empirical models, which give a qualitative evaluation of parametric dependencies.

scholarly journals Variable Surface Temperature Distribution as a Criticality Indicator of the Self-Heating Effect in Composites

2018 ◽  
Vol 18 (1) ◽  
pp. 5-12 ◽  
Author(s):  
A. Katunin
Keyword(s):  
Temperature Distribution ◽  
Surface Temperature ◽  
Heating Temperature ◽  
Measurement Techniques ◽  
Critical Value ◽  
The Self ◽  
Heating Effect ◽  
Self Heating ◽  
Surface Temperature Distribution ◽  
Variable Surface

AbstractSince self-heating effect may significantly intensify structural degradation, it is essential to investigate its criticality, i.e. the temperature value at which fatigue fracture is initiated. In this paper, a new and sensitive criticality indicator based on evaluation of evolution of surface temperature distribution was proposed and experimentally validated. It was shown that comparing to other measurement techniques the presented approach allows for precise evaluation of the critical value of the self-heating temperature. The properly determined critical value may be helpful both during design and operation of elements made of polymers and polymeric composite.

SMA (NiTi): The Coupling between Time, Temperature and Cycling Frequency

2012 ◽  
Vol 730-732 ◽  
pp. 853-858
Author(s):  
Vicenç Torra ◽  
Carlota Auguet ◽  
Antonio Isalgue ◽  
Guillem Carreras ◽  
Francisco C. Lovey
Keyword(s):  
Temperature Effects ◽  
Heating Temperature ◽  
The Self ◽  
Dissipated Energy ◽  
Hysteresis Cycle ◽  
Hysteresis Width ◽  
Self Heating ◽  
Heating Effects ◽  
Cycle Shape ◽  
Cycling Frequency

The main interest focuses in the necessary tools for accurate simulation of the damper behavior in their application. It’s essential a well determined knowledge of the dissipated energy and of the hysteresis cycle shape for a correct simulation. The self-heating effects and the coupling between hysteresis and the relevant temperature effects associated to continuous cycling were studied. In particular, the experimental analysis concentrates in the action of cycling frequency on the hysteresis width and on the dissipated energy. The external and the self-heating temperature effects were studied. In particular, the convective actions of cooling in the conditioned air were visualized. The study of self-heating actions at extremely slow cycles, built by strain steps, shows minor latent heat dissipations in the entire sample. For trained samples, the temperature measurements establish that the transformation is “distributed” not “localized” in the complete sample.

scholarly journals Dispersion of Switching Processes in Ferroelectric Ceramics

2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
O. V. Malyshkina ◽  
Anton Yurievich Eliseev ◽  
R. M. Grechishkin
Keyword(s):  
Electric Fields ◽  
Heating Temperature ◽  
Low Frequency ◽  
High Amplitude ◽  
Wide Frequency Range ◽  
The Self ◽  
Ferroelectric Ceramics ◽  
Field Frequency ◽  
Self Heating ◽  
Electric Field Frequency

The influence of the switching processes on self-heating of ferroelectric PZT ceramics samples was studied in high-amplitude sine and meander electric fields in a wide frequency range of 50 to 1500 Hz. It is shown that the linear dependence of the self-heating temperature on the electric field frequency is observed only in low-frequency region. It was found that there exists a maximum on the frequency dependence of the self-heating temperature. The critical frequency fcr corresponding to this maximum depends on both the properties of the material and geometry of the sample.

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