School of Mechanical Engineering Aviad Sasson
School of Mechanical Engineering Seminar
Wednesday, December 05, 2018 at 14.00
Wolfson Building of Mechanical Engineering, Room 206
The Parametric HFGMC Micromechanics for Nonlinear and Damage Modeling of Multiphase Materials
Aviad Levi Sasson
Ph.D. student of Prof. Rami Haj-Ali and Prof. Jacob Aboudi
This study expands the parametric HFGMC capabilities to model and solve engineering problems. New condensed formulation is proposed and proved to yield good results for the effective thermo-mechanical properties and the spatial elastic fields in terms of computing time. For the first time, the parametric HFGMC is extended to predict the effective thermal properties of composite material: coefficients of thermal expansion, effective thermal conductivity and heat capacity at constant pressure and constant volume.
A continuum damage model has been integrated with the parametric HFGMC. This damage model was originated from the principal of energy dissipation proposed by Marigo (1981) model and was coupled with Ledeveze-Lemaitre (1984) model. The Marigo damage model was revised in the current work to eliminate nonphysical behavior under shear loading conditions. The corrected damage model is implemented at the subcell level so each subcell can detect failure due to its local stress state. Material softening behavior due to damage is implemented as well. The isotropic damage law and its evolution generates both an effective anisotropic damage behavior in the global (composite) level and global nonlinear stress-strain response. Several material systems were used to demonstrate the new damage and failure prediction capabilities of the parametric HFGMC. The obtained failure envelops from the parametric HFGMC were compared with experimental results and showed very good agreement. For the first time, micromechanical based failure envelops are matched with new analytical-mathematical expressions for future design and analysis and to reduced computational effort during analyses.
Multiscale analysis of laminated composite structures is proposed by integrating the parametric HFGMC with the classical FE. The multiscale analysis is compared with the experimental results for the cases of notched laminated composite coupons that are subjected to tension and compression loading. In additions, the parametric HFGMC is used to model the mechanical behavior of a Dyneema based soft composite. The new capacities of the parametric HFGMC are shown again to succeed with the prediction of stress-strain curves of soft composite. New experimental tests for the soft composite are designed and proposed in the framework of this study in order to compare the periodic HFGMC prediction with some measurements. The parametric HFGMC shows good agreement with the measured elastic properties. This talk will conclude by discussing potential future extensions of the proposed micromechanical framework.
