Smoothing the Rough Edges: Evaluating Automatically Generated
  Multi-Lattice Transitions
Martha Baldwin Nicholas A. Meisel Christopher McComb
Additive manufacturing is advantageous for producing lightweight components
while addressing complex design requirements. This capability has been
bolstered by the introduction of unit lattice cells and the gradation of those
cells. In cases where loading varies throughout a part, it may be beneficial to
use multiple, distinct lattice cell types, resulting in multi-lattice
structures. In such structures, abrupt transitions between unit cell topologies
may cause stress concentrations, making the boundary between unit cell types a
primary failure point. Thus, these regions require careful design in order to
ensure the overall functionality of the part. Although computational design
approaches have been proposed, smooth transition regions are still difficult to
achieve, especially between lattices of drastically different topologies. This
work demonstrates and assesses a method for using variational autoencoders to
automate the creation of transitional lattice cells, examining the factors that
contribute to smooth transitions. Through computational experimentation, it was
found that the smoothness of transition regions was strongly predicted by how
closely the endpoints were in the latent space, whereas the number of
transition intervals was not a sole predictor.