Studying the effect of design microscale factors on the thermoelastic response of carbon nanotube-reinforced metal nanocomposites using the finite element micromechanics method

Abstract

Thermoelastic constants seem to be important in designing metal-based composite structures under temperature variations. In the current research, the finite element (FE) model has been utilized as a numerical tool to predict equivalent thermoelastic constants of the aluminum matrix composite (AMC) filled with carbon nanotubes (CNTs). The representative volume element of the model has been constructed such that CNTs are randomly oriented and dispersed into the AMC. As an important microstructural factor involved in the CNT-filled AMC, the interfacial reaction product between the two basic phases which may be generated during the composite fabrication has been taken into account. To understand the effect of critical microstructural factors, the equivalent thermoelastic constant of the CNT-filled AMC has been plotted as a function of the percentage and diameter of the nanotube, as well as the elastic modulus, Poisson’s ratio, thermoelastic property and size of the interfacial region. Since CNTs seldom remain straight inclusions, both straight and wavy configurations of nanotubes have been micromechanically analyzed. When the CNT volume fraction is 5%, the thermoelastic constants of the AMC containing wavy and straight CNTs are 21.8 × 10–6 1/K and 20.6 × 10–6 1/K, respectively. A parametric study has been carried out to understand the role of alignment of CNTs in the AMC thermoelastic constant. It is found when the nanotube content is 5 vol%, the thermoelastic constants of the AMC containing randomly oriented and aligned CNTs are 21.8 × 10–6 1/K and 19.8 × 10–6 1/K, respectively. The FE method has been utilized to estimate the equivalent thermoelastic constants of unidirectionally AMCs reinforced by long and short CNTs with the wavy configuration. Comparisons have been made between the present FE predictions and experiments as well as results of other micromechanics approaches. © The Author(s), under exclusive licence to The Brazilian Society of Mechanical Sciences and Engineering 2024.