The additive manufacturing of glass offers unparalleled design freedom for optical and microfluidic components. However, this process is accompanied by substantial challenges, including steep thermal gradients, phase transitions, and deformations. In this work, we present a coupled thermo-mechanical simulation framework for the three-dimensional printing of vitreous silica (SiO \(_2\) ) and the phase transformation of glass during the 3D printing process. This framework is grounded in a Hamiltonian variational formulation and accounts for the crystalline, amorphous, and liquid phases. The model is implemented in \(\textrm{ANSYS}^{\copyright }\) . A staggered solution scheme combines the Finite Element Method (FEM) for solving displacements (via USERMAT) with the explicit Finite Difference Method (FDM) for temperature and phase transformation updates. This scheme is referred to as the Neighbored Element Method (NEM). Material point cooling rate studies are capable of reproducing the critical vitrification threshold and latent heat plateau. In contrast, full build simulations are able to capture Gaussian deposition profiles, transient temperature fields, deformation, and evolving phase transformations. These results demonstrate the framework’s capacity to predict the coupled thermal, mechanical, and macroscopic phase distribution during glass printing, offering insights for process design aimed at minimizing deformation and achieving high optical clarity.