There is significant interest today in the finite element simulation of various Additive Manufacturing (AM) processes. AM simulation is time-dependent, inherently non-linear, and involves multiple physics. In addition, repeated meshing and insertion of new elements during material deposition can pose significant implementation challenges.
Currently, AM simulation is handled either through a ‘quiet’ approach or an ‘inactive’ approach. In the quiet approach, all finite elements within the workspace are assembled into the global stiffness matrix, and the elements yet to be deposited are assigned ‘void’ material properties. In the inactive approach, only the elements that have been deposited are assembled into the global stiffness matrix. The advantages and disadvantages of the two methods are well documented.
In this paper, we propose a voxel-based, assembly-free framework for AM simulation. This framework presents several advantages including. (1) The workspace is meshed only once at the start of the simulation, (2) addition and deletion of elements is trivial, (3) reduced memory requirement as the global stiffness matrix is never assembled and (4) the underlying linear systems of equations can be solved efficiently through assembly-free methods. We demonstrate the framework here by simulating transient non-linear thermal behaviour of a laser deposition process, with material deposition.
