Ansys material designer modeling of earthen straw bio-composite material for the mechanical behavior prediction

Abstract

Modeling and simulation are powerful tools which have shown their benefits in several sectors by allowing the prediction and/or the understanding of the behavior of objects in the conception phase or already existing. In this paper, construction industry was explored by carrying out 3D modeling of the earthen-straw composite material in order to predict its mechanical properties through ANSYS Material Designer. Hence, this bio-composite material has been modeled as a randomly distributed Short Fibers Reinforced Composite (SFRC) with a random geometry of fibers. Then, the dimensions of the brick were varied in order to study the effect of the brick size on the effective properties of this material. It was concluded that the size of the brick does not influence its mechanical behavior. Thus, the Representative Elementary Volume (REV) of the raw earth brick has been chosen. On the other hand, the effect of fiber volume fraction (Vf) on the elastic properties of this bio-composite material was investigated for the straw contents from 5% to 25% by volume of earthen. It shows that the addition of straw fibers in the earthen matrix with elasticity equal to 2000 MPa has improved its mechanical resistance. Indeed, for 25% of straw fiber's filling rate, we have found 2348 MPa in the young's modulus of the earthen straw composite material, which is equivalent to an increase of 17.4% in this intrinsic parameter. The model was finally validated by its comparison to some well-known analytical model's prediction. The results of ANSYS material designer simulation demonstrate a high level of accuracy compared to analytical methods.