This dissertation is dedicated to the modelling of the glass sagging process. This operation consists in forming a sheet or a plate of glass by heating it in a furnace. Glass temperature rises and reaches a work temperature at which viscosity is low enough to allow glass to sag under its own weight due to gravity. Numerical simulation, based on a thermomechanical model, can help to better understand the influence of the different parameters on the final product, such as the thermal loading, the shape and material of the mould or even the initial geometry of the glass plate. Thus, the commercial software Abaqus® is used to solve the problem by a finite elements method. However, it cannot render the complexity of the radiative heat transfer in glass. So, a Monte Carlo code based on a reciprocal method was developed and validated using benchmarks from the scientific literature. Then, the code was implemented into Abaqus® in order to simulate glass sagging on a mould or glass forming by the draping process. Glass is considered as an elasto-viscoplastic material which obeys a Maxwell model. Viscosity is dependant to temperature according to a WLF law. Special care was devoted to the radiative heat transfer. Different hypothesis are reviewed and performed to check their validity when applied to our numerical set-up.
