Build process simulation of my titanium seatmast topper

Early last year, Andrés Bellés Meseguer reached out to me with a proposition. He had read my piece in Metal AM magazine, and wanted to use my printed parts from DRT Medical Morris to verify a build process simulation workflow that he created using Abaqus. I agreed, and with Dave Bartosik's help I got him the build files necessary to simulate the print.

Andrés' full results were published in a paper titled Prediction of Distortion of a Titanium Bike Part Built by DMLS, which he presented at a NAFEMS conference in November. The simulation used a fine hexagonal mesh at the part itself, and a coarser mesh for the surrounding powder bed and the build platform. At each time step, heat (representing energy applied by the laser) is applied to nodes throughout the model; it then dissipates throughout the structure. Below, see a thermal map of the part about 70 minutes into the build:

You can also use this simulation to model distortion in the part - seen here at the end of the build:

The distorted areas in the simulation correspond well to the as printed part, but Andrés notes that the magnitude values don't match perfectly; it's likely that some of the discrepancy can be narrowed by adjusting thermal coefficients.

This field - simulating additive processes to predict and compensate for built in stress and distortion - is one that I've been excited about since I began working with AM. Thanks to Andrés for sharing his work - I'm looking forward to more progress on this soon.