Effect of nanocomposites rate on the crack propagation in the adhesive of single lap joint subjected to tension

Abstract

The incorporation of nanofillers makes it possible to permanently modify the properties of the adhesive. Nanoparticles with structures of less than 100 nanometers can be incorporated in suitable amounts up to 30% by volume into liquid adhesives without significantly changing the rheology. Fine and nanometric particles of Si02 are now increasingly incorporated into aqueous adhesive dispersions. The objective of this study is to analyze numerically by the three-dimensional finite element method, the intensity and distribution of von Mises, shear and peeling stresses in a nanostructured adhesive joint which ensures the assembly of two plates in Aluminum alloy 2024-T3. This adhesive is epoxy DER 331 in nature, filled with spherical silica nanoparticles (SiO2) of same size, the content of which varies from 0% to 30%. These silica nanoparticles are injected into the adhesive in the liquid state in a homogeneous way in order to see their effects on the mechanical behavior of the epoxy-nanosilica composite. The stresses are also evaluated according to the length of the adhesive lap and its thickness when crossing the crack front. The results obtained numerically by the finite element method show that the addition of nanoparticles in the epoxy matrix with ductile behavior contributes to the improvement of the mechanical properties of the epoxy-nanosilica composite, by increasing its mechanical resistance to the propagation of cracks. The presence of nanoparticles makes it possible to slow down the propagation of the crack.