  Among metal additive manufacturing technologies, powder-bed fusion features
very thin layers and rapid solidification rates, leading to long build jobs and
a highly localized process. Many efforts are being devoted to accelerate
simulation times for practical industrial applications. The new approach
suggested here, the virtual domain approximation, is a physics-based rationale
for spatial reduction of the domain in the thermal finite-element analysis at
the part scale. Computational experiments address, among others, validation
against a large physical experiment of 17.5 $\mathrm{[cm^3]}$ of deposited
volume in 647 layers. For fast and automatic parameter estimation at such level
of complexity, a high-performance computing framework is employed. It couples
FEMPAR-AM, a specialized parallel finite-element software, with Dakota, for the
parametric exploration. Compared to previous state-of-the-art, this formulation
provides higher accuracy at the same computational cost. This sets the path to
a fully virtualized model, considering an upwards-moving domain covering the
last printed layers.
