Beschrijving
Glassy solids such as amorphous polymers or metallic glasses exhibit complex behaviour when subjected to deformation below the glass transition temperature. Sophisticated continuum models are available to simulate this response; they typically give good predictions of the measured monotonic stress-strain data of bulk material systems. However, they require the calibration of a large number of phenomenological parameters and often struggle to accurately predict the response for more complicated loading states such as confinement at the nano- to micro-scale.The use of a mesoscale numerical model based on shear transformation zone (STZs) is an attractive method to bridge standard continuum modelling approaches and atomistic simulations which are typically limited to small length and time scales. Plastic deformation is dictated by conformational changes of molecular segments or atomic clusters (STZs) and their interaction with the linear, elastic matrix. The model sheds light on the role of processing conditions and thermomechanical history on the stress-strain response of an amorphous solid with only a few physical fitting parameters and can be used to explore possible size effects in e.g. (1) fibre-reinforced composites where the glassy matrix is confined by the stiffer fibers or (2) in strong and ductile nanolaminates comprising alternating layers of crystalline and amorphous metallic layers.
The scope of this contribution is to introduce the theoretical framework of the STZ model and its implementation in a commercial FE software package. The model's code is open source and is published as supplementary information to the accompanying paper [1]. In addition, we explore possible routes to calibrate the model based on limited measurement data and discuss practical case studies were the mesoscale model can be used to reveal and exploit possible material size effects.
| Periode | 3 mei 2024 |
|---|---|
| Evenementstitel | 2nd MecaNano General Meeting |
| Evenementstype | Congres |