Effective thermal and mechanical properties of randomly oriented short and long fiber composites

Muhamad Shafiq Sukiman (1, 2) , Toufik Kanit (2, 1) , Franck N'Guyen (3) , Abdellatif Imad (1, 2) , Ahmed El Moumen (4, 5) , Fouad Erchiqui (6)

1 Université de Lille, Sciences et Technologies
2 LML - Laboratoire de Mécanique de Lille - FRE 3723
3 MAT - Centre des Matériaux
4 ENSTA Bretagne - École Nationale Supérieure de Techniques Avancées Bretagne
5 IRDL - Institut de Recherche Dupuy de Lôme
6 UQAT - Université du Québec en Abitibi-Témiscamingue

The microstructure studied in this paper is a Composite made up of Randomly oriented Short Fibers (RSFC) and a computational homogenization is performed to investigate its effective properties. The area fraction is also varied to study its effect on the size of the Deterministic Representative Volume Element (DRVE). It appeared that at certain area fractions, the RSFC does not respect the convergence of the apparent properties calculated under different boundary conditions. This indicates that it does not adhere to the definition of the DRVE in the studied range of scale. The concerned area fraction is found to be around the percolation threshold. The present work consists primarily in investigating the causes of this problem by studying an extreme example of a percolating medium which is a Composite made up of Randomly oriented Long Fibers (RLFC). By identifying the contributing factors, the calculability of the DRVE of a random composite can be predicted by simple verification of the microstructure morphology.

Keywords: Representative volume element; Numerical homogenization; Random media; Composite materials; Short fiber; Long fiber

Domains: Engineering Sciences [physics]

Muhamad Shafiq Sukiman, Toufik Kanit, Franck N'Guyen, Abdellatif Imad, Ahmed El Moumen, et al.. Effective thermal and mechanical properties of randomly oriented short and long fiber composites. Mechanics of Materials, 2017, 107, pp.56-70. ⟨10.1016/j.mechmat.2017.02.002⟩. ⟨hal-01483533⟩