סמינר מחלקה של אורי ברימן דוקטורנט - פורמולציה מיקרומכאנית חדשה לחיזוי נזק וכשל בחומרים מרוכבים החווים עיבורים סופיים.
School of Mechanical Engineering Seminar
Wednesday, February 23, 2022, at 14:00
Wolfson Building of Mechanical Engineering, Room 206
A New Finite-Strain Micromechanical Formulation for
Damage and Failure of Composite Materials
PhD student of Prof. Rami Haj-Ali and Prof. Jacob Aboudi
Coupled nonlinear mechanical analysis of composite materials is desired at both micro and macro-scales, as the overall response is strongly dependent on the evolving microstructure due to the nonlinear and damage behavior of the phases or constituents. A common macro-scale approach is to derive the mechanical stress-strain relations from complex strain-energy density function using average stress or strain variables or invariants, with limited geometrical features, such as fiber orientation and distribution. An alternative direct and refined finite-strain micromechanical formulation is proposed in this study for the damage and failure analysis of composite materials. To that end, the parametric high fidelity generalized method of cells (PHFGMC) formulation is extended for finite-strains and large deformations. The new finite-strain PHFGMC significantly reduces the complication of calibrating the macro energy function of the entire composite by simply calibrating the isotropic energy of the phases and homogenizing them to produce the anisotropic composite behavior. Therefore, the PHFGMC can simulate heterogeneous periodic media with general microstructures (e.g., fiber volume fraction, voids, microcracks, fiber waviness). An incremental-iterative numerical scheme is developed to solve the finite-strain PHFGMC equations. In addition, progressive failure is also proposed using the energy limiters approach. Different elastic and failure analyses of composite materials with periodic microstructure will be presented. The new finite-strain PHFGMC can predict the local and global responses of a wide range of heterogeneous materials, such as soft tissue and engineered aerospace composites.
Link to the seminar (via Zoom):