Determination of elastic properties of polymer nanocomposites using embedded element method

Download
2022-2
Altay, Aysu Elif
Composites are preferred in different industries due to their high strength and lightness. Carbon nanotube (CNT) reinforced polymer composites are preferred composites due to their superior mechanical properties. CNTs in the material increase the stiffness of the structure positively, but the presence of CNTs makes the structure heterogeneous. The objective of this study is to determine the effective elastic properties of polymer nanocomposites using the embedded element method. Due to their nanosize, finite element analysis of CNT reinforced polymer nanocomposites requires high computation power. In the embedded element method, the finite element mesh of the CNTs and the matrix do not need to be compatible, which provides convenience in modeling. Hence, the embedded element method, which is one of the modeling techniques of the Abaqus software, is selected in this study. Representative Volume Elements (RVEs) are generated, and computational homogenization analyses are conducted using the embedded element method. The results of the conventional finite element method and the embedded element method are compared. Since a single CNT in the heterogeneous structure does not accurately represent reality, models containing randomly-placed and randomly-oriented CNTs are created. The effect of small aggregation on the homogenization process is studied since CNTs tend to agglomerate due to their inherent nature. Finally, the number of minimum CNTs required in computational homogenization is determined by a numerical convergence study. Commercial finite element program Abaqus is used for all analyses in this study, and Python software is utilized to compute homogenized properties and generate RVEs.

Suggestions

MECHANICAL PROPERTIES OF REPAIRED CARBON FIBER REINFORCED POLYMER COMPOSITES
Sonat, Emine Evren; Özerinç, Sezer; Department of Mechanical Engineering (2021-12-10)
Carbon fiber reinforced polymer (CFRP) composites are increasingly used in the aerospace industry due to their high specific strength compared to conventional metallic materials. However, a significant shortcoming of these composites is their increased susceptibility to damage. Structural repair is a common method to restore the load-carrying capacity of a damaged part when the damage size exceeds the pre-defined tolerances. Scarf and stepped bonded repair methods are the primary choice for cases that requi...
Investigation of SiCp reinforced aluminium matrix composites by shear and longitudinal ultrasonic waves
Gür, Cemil Hakan (2001-11-01)
SiC particulate reinforced aluminium matrix composites are attractive materials for automotive and aerospace applications because of their outstanding stiffness and strength as compared to the aluminium alloys, in addition to the low cost of particulate reinforcement. The aim of this study is to establish correlations between ultrasonic wave velocities and SiC content, microstructure and mechanical properties of SiC reinforced Al composites, Specimens were fabricated for various volume fraction and size com...
ESTIMATING THE EFFECT OF CHIRALITY AND SIZE ON THE MECHANICAL PROPERTIES OF CARBON NANOTUBES THROUGH FINITE ELEMENT MODELLING
Zuberi, Muhammad Jibran Shahzad; Esat, Volkan (2014-06-27)
Carbon nanotubes (CNTs) are considered to be one of the contemporary materials exhibiting superior mechanical, thermal and electrical properties. A new generation state-of-the-art composite material, carbon nanotube reinforced polymer (CNTRP), utilizes carbon nanotubes as the reinforcing fibre element. CNTRPs are highly promising composite materials possessing the potential to be used in various areas such as automotive, aerospace, defence, and energy sectors.
Analysis of magnesium addition, hydrogen porosity and T6 heat treatment effects on mechanical and microstructural properties of pressure die cast 7075 aluminum alloy
Alat, Ece; Kalkanlı, Ali; Department of Metallurgical and Materials Engineering (2012)
Aluminum alloys are having more attention due to their high specific stiffness and processing advantages. 7075 aluminum alloy is a wrought composition aluminum alloy in the Al-Zn-Mg-Cu series. Due to the significant addition of these alloying elements, 7075 has higher strength compared to all other aluminum alloys and effective precipitation hardenability characteristic. On the other hand, aluminum alloys have some drawbacks, which hinder the widespread application of them. One of the most commonly encounte...
Improvement of organoclay dispersion into polystyrene-based nanocomposites by incorporation of SBS and maleic anhydride-grafted SBS
Dike, Ali Sinan; Yılmazer, Ülkü (SAGE Publications, 2020-04-01)
In this study, organoclay-containing polystyrene (PS)-based nanocomposites were fabricated by extrusion in the presence of thermoplastic elastomer modifiers. Styrene-butadiene-styrene (SBS) rubber was used as the elastomeric compatibilizer and maleic anhydride (MA) was grafted onto SBS rubber at different ratios. Grafting was made via melt blending. Cloisite (R) 30B was used as the organoclay and it was added to PS and PS/SBS blends using a corotating twin-screw extruder, followed by injection molding. Clay...
Citation Formats
A. E. Altay, “Determination of elastic properties of polymer nanocomposites using embedded element method,” M.S. - Master of Science, Middle East Technical University, 2022.