Effect of Fiber Geometry and Representative Volume Element on Elastic and Thermal Properties of Unidirectional Fiber-Reinforced Composites

Abstract

The aim of present work is focused on the evaluation of elastic and thermal properties of unidirectional fiber-reinforced polymer composites with different volume fractions of fiber up to 0.7 using micromechanical approach. Two ways for calculating the material properties, that is, analytical and numerical approaches, were presented. In numerical approach, finite element analysis was used to evaluate the elastic modulus and thermal conductivity of composite from the constituent material properties. The finite element model based on three-dimensional micromechanical representative volume element (RVE) with a square and hexagonal packing geometry was implemented by using finite element code ANSYS. Circular cross section of fiber and square cross section of fiber were considered to develop RVE. The periodic boundary conditions are applied to the RVE to calculate elastic modulus of composite. The steady state heat transfer simulations were performed in thermal analysis to calculate thermal conductivity of composite. In analytical approach, the elastic modulus is calculated by rule of mixture, Halpin-Tsai model, and periodic microstructure. Thermal conductivity is calculated analytically by using rule of mixture, the Chawla model, and the Hashin model. The material properties obtained using finite element techniques were compared with different analytical methods and good agreement was achieved. The results are affected by a number of parameters such as volume fraction of the fibers, geometry of fiber, and RVE.

The Elastic Properties of Unidirectional Bamboo Fibre Reinforced Epoxy Composites

“…It can be seen in Fig.8 that the transverse modulus increase as bamboo fibre volume fraction is increased but not in a linear fashion as does the longitudinal modulus. While the changing trend is shared by all models and similar to past studies [21], the FEA square RVE model gives the highest values of E 2 , followed by the Halpin-Tsai model and the FEA hexagonal RVE model, while the ROM model give the lowest values. It can also be seen that the plot for the FEA hexagonal RVE model closely agrees with the plot for the Halpin-Tsai model.…”

“…At the same time, the loads can come from the stress and strain simultaneously. Applying circular and rectangular cross-sections of fibres in square and hexagonal RVE, Devireddy and Biswas [21] conducted FEA on variety of the RVEs to give elastic and thermal properties of unidirectional fibre-reinforced composites while assuming the unidirectional composites showed transversely isotropic properties. Babu et al [22] moved further in developing RVE for short fibre composites where mathematical theory of homogenization with periodic boundary conditions were used.…”

Numerical Estimation Method of Orthotropic Material Properties of a Roving for Reinforcement of Composite Materials

“…In consideration of the relationships (8) it is enough to model two axial tensions and two plane shears with the roving model-cell.…”

“…For the roving model-cell with Volume V, the average strain and stress can be introduced and defined as follows [7], [8], [11]:…”

Effect of fiber cross section geometry on cyclic plastic behavior of continuous fiber reinforced aluminum matrix composites

“…It is well know that the main factors that influence the mechanical response of a general MMC are the mechanical properties of the constituents, the fiber arrangement, the reinforcement fraction volume and its shape (Böhm et al, 1993;Devireddy and Biswas, 2014;Giugliano and Chen, 2016;Hashin, 1983;Srivastava et al, 2011;Xu et al, 1999). The fatigue behavior of MMCs has also been investigated by many researchers with emphasis on the crack propagation rates and low cycle fatigue response under both thermal fatigue and thermo mechanical fatigue.…”