The effect of internal temperature rise on the tensile behavior of polymeric materials at subambient temperatures

1970 ◽  
Vol 14 (11) ◽  
pp. 2797-2814 ◽  
Author(s):  
J. Skelton ◽  
W. D. Freeston ◽  
M. M. Schoppee
Keyword(s):  
Temperature Rise ◽  
Polymeric Materials ◽  
Tensile Behavior ◽  
Internal Temperature

Stress Analysis of a Tire Under Vertical Load by a Finite Element Method

1977 ◽  
Vol 5 (2) ◽  
pp. 102-118 ◽  
Author(s):  
H. Kaga ◽  
K. Okamoto ◽  
Y. Tozawa
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Program ◽  
Temperature Rise ◽  
Strain Energy ◽  
Internal Stresses ◽  
Vertical Load ◽  
The Finite Element Method ◽  
Internal Temperature ◽  
Element Method

Abstract An analysis by the finite element method and a related computer program is presented for an axisymmetric solid under asymmetric loads. Calculations are carried out on displacements and internal stresses and strains of a radial tire loaded on a road wheel of 600-mm diameter, a road wheel of 1707-mm diameter, and a flat plate. Agreement between calculated and experimental displacements and cord forces is quite satisfactory. The principal shear strain concentrates at the belt edge, and the strain energy increases with decreasing drum diameter. Tire temperature measurements show that the strain energy in the tire is closely related to the internal temperature rise.

scholarly journals On nonlinear thermo-electro-elasticity

2016 ◽  
Vol 472 (2190) ◽  
pp. 20160170 ◽  
Author(s):  
Markus Mehnert ◽  
Mokarram Hossain ◽  
Paul Steinmann
Keyword(s):  
Boundary Value Problem ◽  
Total Energy ◽  
Constitutive Equations ◽  
Cylindrical Tube ◽  
Polymeric Materials ◽  
Temperature History ◽  
Internal Temperature ◽  
Laws Of Thermodynamics ◽  
Electric Loads ◽  
Coupled Loads

Electro-active polymers (EAPs) for large actuations are nowadays well-known and promising candidates for producing sensors, actuators and generators. In general, polymeric materials are sensitive to differential temperature histories. During experimental characterizations of EAPs under electro-mechanically coupled loads, it is difficult to maintain constant temperature not only because of an external differential temperature history but also because of the changes in internal temperature caused by the application of high electric loads. In this contribution, a thermo-electro-mechanically coupled constitutive framework is proposed based on the total energy approach. Departing from relevant laws of thermodynamics, thermodynamically consistent constitutive equations are formulated. To demonstrate the performance of the proposed thermo-electro-mechanically coupled framework, a frequently used non-homogeneous boundary-value problem, i.e. the extension and inflation of a cylindrical tube, is solved analytically. The results illustrate the influence of various thermo-electro-mechanical couplings.

scholarly journals Study on the Method of Calculating Temperature Rise of Transformer

2020 ◽  
Vol 179 ◽  
pp. 01027
Author(s):  
Tao Li ◽  
Xiaoping Du ◽  
Xuewu Sun ◽  
Yuanyuan Song
Keyword(s):  
Temperature Rise ◽  
Thermal State ◽  
Hot Spot ◽  
Scientific Basis ◽  
Internal Temperature ◽  
Insulation Aging ◽  
The Neural Network ◽  
Forecasting Method ◽  
Transformer Winding ◽  
Spot Temperature

The internal temperature of the transformer is a key parameter to measure the thermal state of the transformer. The service life of the transformer generally depends on the life of the insulating material, and high temperature is the main reason why cause insulation aging, this paper studies the temperature rise of transformer winding hot spot temperature for the key, using the neural network forecasting method, forecasts transformer winding hot spot temperature change rule, calculate the transformer internal temperature rise, provide the temperature of the scientific basis for the safe operation of the transformer.

Temperature Rise in Polymeric Materials During High Rate Deformation

2008 ◽  
Vol 75 (1) ◽  
Author(s):  
M. Garg ◽  
A. D. Mulliken ◽  
M. C. Boyce
Keyword(s):  
Strain Rate ◽  
Temperature Rise ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Polymeric Materials ◽  
Test System ◽  
High Rate ◽  
Single Element ◽  
Strain Rates ◽  
Work Of Deformation

Many polymeric materials undergo substantial plastic strain prior to failure. Much of this post yield deformation is dissipative and, at high strain rates, will result in a substantial temperature rise in the material. In this paper, an infrared (IR) detector system is constructed to measure the rise in temperature of a polymer during high strain rate compression testing. Temperature measurements were made using a high-speed mercury-cadmium-telluride (HgCdTe) single-element photovoltaic detector sensitive in the mid-infrared spectrum (6–12μm), while mechanical deformation was accomplished in a split Hopkinson pressure bar (SHPB). Two representative polymers, an amorphous thermoplastic (polycarbonate (PC)) and a thermoset epoxy (EPON 862/W), were tested in uniaxial compression at strain rates greater than 1000s−1 while simultaneously measuring the specimen temperature as a function of strain. For comparison purposes, analogous measurements were conducted on these materials tested at a strain rate of 0.5s−1 on another test system. The data are further reduced to energy quantities revealing the dissipative versus storage character of the post yield work of deformation. The fraction of post yield work that is dissipative was found to be a strong function of strain for both polymers. Furthermore, a greater percentage of work is found to be dissipative at high rates of strain (>1000s−1) than at the lower rate of strain (0.5s−1) for both polymers; this is consistent with the need to overcome an additional energy barrier to yield at strain rates greater than 100s−1 in these two polymers. The highly cross-linked thermoset polymer was found to store a greater percentage of the post yield work of deformation than the physically entangled thermoplastic.

scholarly journals Investigating mechanical properties of 3D printed parts manufactured in different orientations on Multijet printer

2021 ◽  
Author(s):  
Ramesh Chand ◽  
Vishal S Sharma ◽  
Trehan Rajeev
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Mechanical Behavior ◽  
Polymer Material ◽  
Polymeric Materials ◽  
Tensile Behavior ◽  
Jet Printing ◽  
3D Printed

Abstract Polymer material based products in the engineering field are most widely produced by the multi jet printing (MJP). These products impart inherent benefits in manufacturing intricate contours and shapes at less additional expenses. This emphasizes the importance of studying the mechanical behavior of the manufactured parts, using polymeric materials in different orientations. In this investigation density, tensile behavior & hardness were studied for 3D-printed parts produced in four different orientations (A, B, C and D). It is found that for the best mechanical properties part should be fabricated using orientation ‘A’. Furthermore, for density and tensile strength part should not be fabricated using orientation ‘C’. Also in case of hardness part should not be fabricated in orientation ‘B’.

Evaluation of the Resistance of a Polypropylene Geotextile Against Ultraviolet Radiation

2018 ◽  
Vol 25 (1) ◽  
pp. 196-202 ◽  
Author(s):  
José Ricardo Carneiro ◽  
Paulo Joaquim Almeida ◽  
Maria de Lurdes Lopes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ultraviolet Radiation ◽  
Radiant Energy ◽  
Polymeric Materials ◽  
Tensile Behavior ◽  
Polypropylene Fibers ◽  
Premature Failure ◽  
Ultraviolet Aging ◽  
Scanning Electron

AbstractThe exposure to solar radiation (mainly due to the action of ultraviolet radiation) is one of the main causes for the premature failure of many polymeric materials, including the geotextiles. In this work, a nonwoven polypropylene geotextile (stabilized with a known amount of a hindered amine light stabilizer) was exposed to ultraviolet-aging tests, both in the laboratory (accelerated conditions) and outdoors (natural conditions). The damage occurred in the geotextile (caused by the ultraviolet-aging tests) was evaluated quantitatively (by monitoring changes in its mass per unit area, thickness, and tensile properties) and qualitatively (by scanning electron microscopy). The results, among other findings, showed that: (1) the ultraviolet-aging tests (both in the laboratory and outdoors) induced relevant damage in the polypropylene fibers of the geotextile (transverse cracks), leading to the deterioration of its tensile behavior, (2) the amount of degradation increased with the increase of the ultraviolet radiant energy, (3) the laboratory tests caused a faster deterioration of the polypropylene fibers than the outdoor tests, and (4) the degradation found by scanning electron microscopy in the polypropylene fibers correlated well with the deterioration occurred in the tensile behavior of the geotextile.

Ignition and extinction of a reaction in the presence of increasing external temperature: general results and slow temperature rise

1992 ◽  
Vol 438 (1902) ◽  
pp. 145-152 ◽  
Keyword(s):  
Chemical Reaction ◽  
Temperature Rise ◽  
Homogeneous Model ◽  
Local Maximum ◽  
Internal Temperature ◽  
External Temperature ◽  
First Order ◽  
Exothermic Chemical Reaction

We consider a homogeneous model for a first order, exothermic chemical reaction subjected to a linearly increasing external temperature. With u and v representing dimensionless internal temperature and concentration respectively, d u /d t ═ v exp [ u /( 1 + ∊ u )] – c ( u – βt ), d v /d t ═ – ∊ A v exp [ u /(1 + ∊ u )]. We examine the conditions under which the temperature u attains a local maximum and minimum, or alternatively is always increasing with time t .

Managing optical heating via Al3+-doping in Er3+:SrF2 powder phosphors prepared by combustion synthesis

2019 ◽  
Vol 48 (14) ◽  
pp. 4589-4595 ◽  
Author(s):  
Nikifor Rakov ◽  
Renato B. Guimarães ◽  
Glauco S. Maciel
Keyword(s):  
Combustion Synthesis ◽  
Temperature Rise ◽  
Internal Temperature ◽  
Optical Heating

Internal temperature rise due to optical heating in Er3+-doped SrF2 powder phosphors with and without Al3+ ions.

Measurement of Internal Temperature Rise of Transistors

1958 ◽  
Vol 46 (6) ◽  
pp. 1207-1208 ◽  
Author(s):  
J. Nelson ◽  
J. Iwersen
Keyword(s):  
Temperature Rise ◽  
Internal Temperature

scholarly journals Temperature Rise Characteristics and Error Analysis of a DC Voltage Divider

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1914
Author(s):  
Zhengyun Fang ◽  
Yi Luo ◽  
Shaolei Zhai ◽  
Bin Qian ◽  
Yaohua Liao ◽  
...  
Keyword(s):  
Temperature Rise ◽  
Measurement Accuracy ◽  
Heat Dissipation ◽  
Performance Indicator ◽  
Voltage Divider ◽  
Internal Resistance ◽  
Working Time ◽  
Internal Temperature ◽  
Dc Voltage ◽  
High Voltage Direct Current

Measurement accuracy is an important performance indicator for high-voltage direct current (HVDC) voltage dividers. The temperature rise effect for a HVDC voltage divider’s internal resistance has an adverse effect on measurement accuracy. In this paper, by building a solid model of a DC voltage divider, the internal temperature rise characteristic and error caused by the temperature rise in a resistance voltage divider were theoretically simulated. We found that with the increase in height and working time, the internal temperature of the voltage divider increased. The results also showed that the lowest temperature was near the lower flange and the highest temperature was near the upper flange in the middle of the voltage divider. The error caused by the temperature rise increased first and then decreased gradually with divider height, increasing with its working time. The measurement error caused by the internal temperature difference in steady state reached a maximum of 158.4 ppm. This study provides a theoretical basis to determine the structure and accuracy improvement for a resistive voltage divider, which is helpful for the selection of components and the optimization of the heat dissipation structure.

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