Following on from Laurence’s post on new features in Abaqus 2017, the latest release has some interesting new keywords that are really useful for process simulation of Additive Manufacturing (AM). Using Element Progressive Activation and a subroutine the user can switch elements on and off at specific times in an analysis. This procedure is available for both Heat Transfer and Static stress analysis, providing a capability to predict residual stresses from thermal AM processes.
The results shown illustrate an analysis of a simple part after being printed in Inconel, cooled to room temperature and removed from the build plate (I’ve scaled the deformation ×10 to make things clearer). The new keywords integrate easily into the analysis and allow all the Abaqus material modelling capabilities to be used. The subroutine that controls element switching was generated automatically from G-code using a VBA script. There have been some interesting things said about the time required to run AM simulations, so for the record this took a total of 30 minutes (8 minutes for the Heat Transfer and 22 minutes for the Static analysis). The second video shows a static analysis of the print process of a thin vertical wall, showing how the methods used are able to capture non-linear features of the process such as buckling instability.
The development of reliable process simulation will bring AM into line with other manufacturing methods where process simulation is considered the norm. There’s still a way to go with all of this, in particular some interesting challenges with multi-scale modelling of materials but the basic tools to build reliable analyses are now becoming available.
We’ve put together a pdf file of the highlights of the 2017 release and its available for download here.