scholarly journals Thermal Property Evaluation of Porous Asphalt Concrete Based on Heterogeneous Meso-Structure Finite Element Simulation

2020 ◽  
Vol 10 (5) ◽  
pp. 1671 ◽  
Author(s):  
Yanjing Zhao ◽  
Jiwang Jiang ◽  
Yiqing Dai ◽  
Lan Zhou ◽  
Fujian Ni

Porous asphalt concrete (PAC) can obviously improve vehicle driving safety on rainy days and reduce environmental noise. It has been widely used in China. The existence of a large number of interconnected voids in PAC makes a significant difference in heat transfer and temperature distribution from conventional dense-graded asphalt concretes (AC). In this paper, the internal structure images of three dense-graded asphalt mixtures and one PAC were obtained by X-ray CT scanning technology, and the internal meso-structure finite element simulation models of asphalt mixtures were established by using the mapped meshing method. The temperature variations of asphalt mixture specimens during laboratory cooling and heating processes were simulated in this study, and laboratory tests were carried out to verify the simulation accuracy. Due to the simulation results, it was found that the thermal characteristics of the PAC mixture were different from those of the dense-graded asphalt mixture due to the large interconnected air void content in the PAC mixture. The temperature field in the PAC mixture was more sensitive to ambient air temperature under laboratory conditions. Moreover, in PAC specimens, temperature distributed more unevenly than in dense-grade asphalt mixtures. Therefore, it is necessary to consider the internal meso-structure of porous asphalt mixtures while simulating the temperature field in PAC specimens or pavement structures.

Applied laser ◽  
2010 ◽  
Vol 30 (4) ◽  
pp. 284-290
Author(s):  
凡进军 Fan Jinjun ◽  
赵剑峰 Zhao Jianfeng

2018 ◽  
Vol 242 ◽  
pp. 01022
Author(s):  
Liu Heping ◽  
Sun Fenger ◽  
Yibo Fenger ◽  
Cheng Shaolei ◽  
Liu Bin

In this paper, the finite element simulation of GH4169 high temperature alloy by selective laser melting was carried out, and the microstructure was analyzed by experiments. The results show that the shape of the temperature field cloud formed by the laser heat source is different from the shape of the theoretical model, but is in the shape of the ellipse. The temperature gradient at the front end of the molten pool is larger than that of the back end of the molten pool, and the isotherm of the front end of the molten pool is more intensive. The temperature of the substrate is less affected by the temperature gradient. The temperature gradient of the front end of the melting pool is larger than the back end of the molten pool, and the temperature field of selective laser melting is like a meteor with trailing tail. In the laser heat source, the temperature isotherm is the most dense and the temperature gradient is maximum. The relative effect of mechanical properties of δ phase is very complex. When the phase is precipitated by widmanstatten structure, it is easy to produce stress concentration as a source of cracks


2011 ◽  
Vol 4 (3) ◽  
pp. 824-829
Author(s):  
Xuda Qin ◽  
Hao Jia ◽  
Xiaolai Ji ◽  
Xiaotai Sun ◽  
Qi Wang

2012 ◽  
Vol 236-237 ◽  
pp. 536-542 ◽  
Author(s):  
Xiang Lei Duan ◽  
Shu Guang Zuo ◽  
Yong Li ◽  
Chen Fei Jiang ◽  
Xue Liang Guo

To analyze the steady-state temperature field, a three-factor orthogonal test was taken to study comprehensively how the load, speed and tire pressure can influence the tire temperature. The finite element simulation was carried out according to the uncoupled idea. Based on the single-factor analysis towards the speed factor, the actual convection coefficient of different boundaries was determined to calculate the steady-state temperature field at last. These analyses indicate that the tire temperature rise increase with the factor of load and speed, decrease with the increase of the initial tire pressure. The load has the biggest influence on the tire temperature rise, while the speed has the least. With the combination of steady-state temperature field and heat generation rate distribution, all these high-temperature regions can be explained clearly from the finite element perspective.


2011 ◽  
Vol 378-379 ◽  
pp. 345-348
Author(s):  
Hong Guo Xu ◽  
Zhong He Shui ◽  
Bo Chen ◽  
Wei Chen ◽  
Sha Ding

In this paper, infrared imaging and temperature sensor monitoring equipment are used to detect the defect of concrete. By means of experiment and numerical analysis, a nondestructive testing method for concrete based on infrared thermal imaging and the finite element simulation of temperature field was established. Experimental and simulation results show that infrared thermal imaging method and the finite element simulation of temperature field can effectively detect the defect in the sample. When combining such two methods together, the information of internal concrete structure can be revealed more comprehensively and accurately.


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