Numerical and Experimental Investigation of Piezoresistance of Asphalt Concrete Containing Graphite

2016 ◽  
Vol 852 ◽  
pp. 1383-1390
Author(s):  
Ning Tang ◽  
Wen Hao Pan ◽  
Yan Wen Chen ◽  
Min Dai ◽  
Qing Wang
Keyword(s):  
Applied Stress ◽  
Asphalt Concrete ◽  
Laboratory Experiments ◽  
Volume Fraction ◽  
Theoretical Data ◽  
Snow Melting ◽  
Self Monitoring ◽  
Insulating Material ◽  
Conductive Materials ◽  
Interparticle Separation

Asphalt concrete is an insulating material. Conductive materials are added to asphalt concrete in order that improving the conductivity. Conductive asphalt concrete (CAC) has become a promising method to snow melting and self-monitoring. In this study, the piezoresistance of CAC which can be improved the conductivity through graphite are analyzed. Based on the interparticle separation and bitumen film-thickness of graphite particle, a model has been developed to predict the piezoresistance under the applied stress. The influences of applied stress, graphite diameter, graphite volume fraction, compressive modulus on the piezoresistance are interpreted through laboratory experiments. Both the numerical and experimental results show that the theoretical data obtained from the model are found to agree with the experimental ones fairly well. In addition, it was found that all these parameters influence the piezoresistance by altering the change process of interparticle separation of graphite.

Research on the Construction Technology of Self-Monitoring Asphalt Concrete

2021 ◽  
Vol 891 ◽  
pp. 205-210
Author(s):  
Yuan Xu
Keyword(s):  
Asphalt Concrete ◽  
Test Section ◽  
Rolling Process ◽  
Construction Technology ◽  
Self Monitoring ◽  
Mixing Effect ◽  
Steel Wheel ◽  
Mixing Method ◽  
Pavement Construction ◽  
Compaction Degree

Combined with the paving of the test section of Self-monitoring Asphalt Concrete, the electrode burying mode of pavement construction is designed according to its characteristics, and the best mixing method and spreading rolling construction technology are compared and analyzed. The results show that the construction structure of the test section is reasonable and feasible, the best mixing effect can be obtained by adding conductive phase material and asphalt at the same time, and the rolling process. The order of rubber wheel and steel wheel compaction has no significant effect on compaction degree.

Creep threshold stresses in TiN-dispersion strengthened stainless steels

1986 ◽  
Vol 404 (1827) ◽  
pp. 339-358 ◽  
Keyword(s):  
Applied Stress ◽  
Stainless Steels ◽  
Threshold Stress ◽  
Volume Fraction ◽  
Particle Dispersion ◽  
Dislocation Climb ◽  
Threshold Condition

Threshold stresses for creep were determined by cumulative stressdecrement tests. The results show the threshold stress to be independent of specimen strain and applied stress but to increase with volume fraction of TiN dispersoid. It is concluded that the threshold stress is derived solely from the presence of the dispersion. This variation of threshold stress has been used to check the predictions of recent models of the threshold condition based on the climb bypass of particles. Extensive measurements of the particle dispersion were used in the comparison. Those models based on general dislocation climb around the particles produce a gross underestimate, by two orders of magnitude of the predicted value of threshold stress. Closest numerical agreement with measurements was obtained by the models which incorporated some degree of localized dislocation climb.

scholarly journals Nano liquid metal for the preparation of a thermally conductive and electrically insulating material with high stability

RSC Advances ◽  
2018 ◽  
Vol 8 (29) ◽  
pp. 16232-16242 ◽  
Author(s):  
P. Fan ◽  
Z. Sun ◽  
Y. Wang ◽  
H. Chang ◽  
P. Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Metal ◽  
High Stability ◽  
Insulating Material ◽  
Conductive Materials ◽  
Thermally Conductive ◽  
Base Polymer

Compared to liquid metal (LM) microdroplets based thermally conductive materials (micro-LM-THEMs), nano LM-THEMs (nLM-THEMs) presents a more stable electric insulating property even upon stress, achieving ~50-fold thermal conductivity over base polymer.

The Influence of Electrode on Resistivity of Conductive Asphalt Concrete for Self-Monitoring

2012 ◽  
Vol 509 ◽  
pp. 203-208 ◽  
Author(s):  
Chang Jun Sun ◽  
Li Juan Qin ◽  
Shao Peng Wu ◽  
Guo Liang Sun ◽  
Lei Chen
Keyword(s):  
Stainless Steel ◽  
Electrode Material ◽  
Asphalt Concrete ◽  
Cross Sectional Area ◽  
The Self ◽  
Sectional Area ◽  
Stainless Steel Mesh ◽  
Cross Sectional ◽  
Self Monitoring ◽  
Electrode Size

This paper focuses on an optimized research about materials and size of electrode of self-monitoring asphalt concrete. It can be easily observed and analyzed the sensitivity of the test and resistivity fluctuations by studying the changes of output resistivity in different electrode embedded in the self-monitoring asphalt concrete. Based on the above method, we can select the proper electrode for the self-monitoring asphalt concrete. The results indicate that the output resistivity of self-monitoring asphalt concrete have much more fluctuation than which used stainless steel mesh as electrode material when choosing the iron mesh as electrode material. Meanwhile, the results demonstrate that the measured output resistivity of self-monitoring asphalt concrete is the most stable when the electrode size is 40~60% of cross-sectional area.

Analysis on the Distribution Law of WC Particles during Centrifugal Casting Process

2011 ◽  
Vol 117-119 ◽  
pp. 1610-1613
Author(s):  
Zhen Kai Zhao ◽  
Yan Pei Song ◽  
Zhi Ming Feng
Keyword(s):  
Volume Fraction ◽  
Centrifugal Casting ◽  
Particle Volume Fraction ◽  
Composite Layer ◽  
Theoretical Data ◽  
Casting Process ◽  
Mathematical Equation ◽  
Distribution Law ◽  
Particle Volume ◽  
Gradient Distribution

The mathematical physical model of the unmelted WC particle distribution in the centrifugal force field was established in cylindrical coordinate system using continuity theory and hydromechanics. According to the migration rule of WC particle in the Fe-C alloy melt under centrifugal field, the mathematical equation of particle volume fraction distribution including centrifugal casting parameters was formulated. The mathematical equations were calculated by solving the mathematical equation with numerical analysis, and also the distribution regularity of WC particle in composite layer under different temperature and different Centrifugal speed was achieved. The results show that the particle reinforced composite with a gradient distribution along thickness was prepared by centrifugal casting. The gradient distribution of the particle changes with pouring temperature and centrifugal speed. And the theoretical data accord with experiment data compared to the experimental measurement.

scholarly journals Research on a mechanical model of magnetorheological fluid different diameter particles

2021 ◽  
Vol 11 (1) ◽  
pp. 158-166
Author(s):  
Jun Qiu ◽  
Yiping Luo ◽  
Yuqing Li ◽  
Jiao Luo ◽  
Zhibin Su ◽  
...  
Keyword(s):  
Experimental Data ◽  
Shear Stress ◽  
Mechanical Model ◽  
Volume Fraction ◽  
Silicone Oil ◽  
Theoretical Data ◽  
Magnetorheological Fluid ◽  
Average Error ◽  
Shear Strain Rate ◽  
Particle Volume

Abstract In this paper, the chain structure of magnetorheological fluid (MRF) magnetic particles was studied and analyzed, the mechanical model of MRF with different diameter ferromagnetic particles was established, silicone oil-based MRF with different particle volume fractions was prepared, the shear properties of the MRF were tested, and the theoretical and experimental data were compared. The experimental results show that the shear stress is stable with the increase of shear strain rate under the action of the magnetic field, and it has a shear thinning effect. The shear stress increases linearly with the increase of particle volume fraction. The shear stress increases with the increase of magnetic induction intensity. After data analysis and in the case of control variables, the average error of improved theoretical data and experimental data is lower than that of previous theoretical data and experimental data, which verifies that the improved theory (mechanical model) has a certain accuracy.

scholarly journals Heat Transfer of Nanofluid in a Double Pipe Heat Exchanger

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Reza Aghayari ◽  
Heydar Maddah ◽  
Malihe Zarei ◽  
Mehdi Dehghani ◽  
Sahar Ghanbari Kaskari Mahalle
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Volume Fraction ◽  
Theoretical Data ◽  
Experimental Results ◽  
Double Pipe ◽  
Pipe Heat

This paper investigates the enhancement of heat transfer coefficient and Nusselt number of a nanofluid containing nanoparticles (γ-AL2O3) with a particle size of 20 nm and volume fraction of 0.1%–0.3% (V/V). Effects of temperature and concentration of nanoparticles on Nusselt number changes and heat transfer coefficient in a double pipe heat exchanger with counter turbulent flow are investigated. Comparison of experimental results with valid theoretical data based on semiempirical equations shows an acceptable agreement. Experimental results show a considerable increase in heat transfer coefficient and Nusselt number up to 19%–24%, respectively. Also, it has been observed that the heat transfer coefficient increases with the operating temperature and concentration of nanoparticles.

scholarly journals Determination of distribution of heat-conducting material concentration in protective layer of TPS panel

2018 ◽  
Vol 240 ◽  
pp. 01007
Author(s):  
Łukasz Brodzik ◽  
Andrzej Frąckowiak
Keyword(s):  
Volume Fraction ◽  
Protective Layer ◽  
Aluminum Surface ◽  
Heat Conducting ◽  
Conducting Material ◽  
Insulating Material ◽  
Conductive Material ◽  
Percentage Volume ◽  
Constant Percentage

Paper presents the problem of heating the damaged insulation of an orbiter. Changes of the insulation’s thermal properties, made by adding conductive material of high value of specific heat in a form of a dope to the protective layer, were examined. The analysis was made using insulating material LI900 and beryllium dope. In the paper was investigated the effect of the dopant’s share on the temperature distribution on the aluminum surface. This influence was depended on the size of the damage, defined by parameter D, as well as a constant percentage volume fraction.

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