Efficiency of the Needle Probe Test for Evaluation of Thermal Conductivity of Composite Materials: Two-Scale Analysis
Autor: | Łydżba Dariusz, Różański Adrian, Rajczakowska Magdalena, Stefaniuk Damian |
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Jazyk: | angličtina |
Rok vydání: | 2014 |
Předmět: | |
Zdroj: | Studia Geotechnica et Mechanica, Vol 36, Iss 1, Pp 55-62 (2014) |
Druh dokumentu: | article |
ISSN: | 0137-6365 2083-831X |
DOI: | 10.2478/sgem-2014-0007 |
Popis: | The needle probe test, as a thermal conductivity measurement method, has become very popular in recent years. In the present study, the efficiency of this methodology, for the case of composite materials, is investigated based on the numerical simulations. The material under study is a two-phase composite with periodic microstructure of “matrix-inclusion” type. Two-scale analysis, incorporating micromechanics approach, is performed. First, the effective thermal conductivity of the composite considered is found by the solution of the appropriate boundary value problem stated for the single unit cell. Next, numerical simulations of the needle probe test are carried out. In this case, two different locations of the measuring sensor are considered. It is shown that the “equivalent” conductivity, derived from the probe test, is strongly affected by the location of the sensor. Moreover, comparing the results obtained for different scales, one can notice that the “equivalent” conductivity cannot be interpreted as the effective one for the composites considered. Hence, a crude approximation of the effective property is proposed based on the volume fractions of constituents and the equivalent conductivities derived from different sensor locations. |
Databáze: | Directory of Open Access Journals |
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