Functions in Simufact Additive

Support of orthotropic material properties

Simufact Additive considers orthotropic material properties, which enables a more realistic representation of the support structure stiffness and conductivity. Coarser meshing maintains reliable results with a simultaneous reduction of the required calculation times.

Individual positioning of parts within the virtual build space

Users can efficiently position components on the base plate and quickly iterate to optimise the component orientation. Part positioning is very intuitive in the user-friendly interface.

Optimise part orientation and alignment

Simufact Additive allows you to compare different options for component orientation and to identify the optimal printing strategy.

Identify Manufacturing Issues

Employ Simufact Additive in order to quickly and reliably identify and predict the following manufacturing issues:

• Predict contact between recoater and component (recoater contact)
• Identify possible part failure and cracks
• Determine layer offset intensity as well as „Shrink lines“
• Predict the influence of the base plate on the part
• Evaluate local and spatially dependent process parameters

Predict the influence of the base plate on the build space

During the additive manufacturing process, distortions and residual stresses occur both in the workpieces and in the base plate. The latter can affect the properties of the support structures and the component. Simufact Additive can be used to determine the properties and influences of the base plate during the build process. After simulation of the build process, the unclamping of the base plate from the machine is also considered. Here, the sequence in which the screws are unclamped can have a further influence on the deformation and stress state of the build space and its parts. As a practical application, the user can, for example, determine when the base plate has become too thin and therefore is no longer stiff enough and needs to be replaced.

Specific manufacturing issues

For the identification of specific manufacturing problems, Simufact Additive offers three methods that support the user during the evaluation of results. They help the user to identify critical areas in the part:

• Recoater contact: The user learns how likely contact is between the recoater and part.
• Possible part failure: A traffic light system indicates how likely it is that the part cracks while printing.
• Layer offset intensity: During the printing process, it is possible that a layer offset occurs, especially when structures grow together. Such an offset between two layers is usually uncritical at first but is often visually undesirable. Also, impacts on the fatigue of the part cannot completely be ruled out either. Thus, a layer offset intensity usually requires additional surface finishing. Within the framework of simulation, the user can identify and optimize critical areas of the part before printing.

Create history and advanced path diagrams

The temporal and spatial tracking of results individual points, the so-called virtual sensors (post particles), enables the user to develope detailed local evaluations.

In many cases, not only the final outcomes are interesting, but also how it has developed until then. For example, how does distortions, stresses and temperatures change during manufacturing processes, by applying new layers, which influences the entire part again and again? A history diagram provides reliable answers.

The colour rendering of the surfaces and internal results by means of sections provides a good overview of the distribution of the results and facilitates the rapid identification of critical extreme points. A more detailed insight into the dependence of the results on their position can be obtained by means of so-called path diagrams. Intermediate results can be easily interpolated automatically so that the meaningfulness of a diagram can be improved with little effort.

The subsequent steps of the printing process such as the stress-reducing heat treatment, cut off and removal of the base plate and support structures and, if necessary, the hot-isostatic-pressing can have significant influences on the quality and accuracy of the part.

You should consider simulating these process steps to achieve print first time right.

Therefore, Simufact Additive not only serves the immediate optimization of the build processes, but also the subsequent processes such as stress relief, cut off and removal of the base plate and support structures as well as HIP. Simufact Additive supports the user to analyse the influence of subsequent steps on the part.

This allows the user to develop strategies for dimensional accuracy across the entire process chain.

• Heat treatment – Prediction of distortions and residual stresses under the influences of high temperature and creep effects
• Cut off the base plate, also for complex scenarios
• Removal of support structures in consideration of the sequence
• Hot-isostatic pressing (HIP) – prediction of distortions, residual stresses and material density (for instance based on the hollow sphere model) under the influence of high temperature and press

The picture sequence shows the gradual reduction of residual stresses within a part during the manufacturing post processing. The result at the end of the simulated process chain is a nearly stress less bracket. The simulation along the process chain makes it possible to optimize the result to the desired result. The parameters of the printing process, heat treatment, cutting and support removal, and HIP can be varied to achieve the desired result.

Stress Relief by heat treatment

The heating and cooling of the metal material as the part is build up layer-by-layer leads to internal stresses that should be relieved before the part is removed from the build plate. Otherwise, the part may warp or even crack during the cutting process.

Simufact calculates the results of the heat treatment stress relief process by considering the applied temperature history, the heat dependent material properties and –which is crucial- the creep effects occurring under elevated temperatures and internal loading by residual stresses. By this the stress relief over time can be simulated in detail and still remaining stresses after the heat treatment can be identified. These stresses would influence the stress and distortion state after the cutting process.

If a quick rough assessment is enough also an engineering approach can be chosen in which the stresses are simply assumed to be set to zero. This reduces the overall calculation time and still delivers practically useful results in most cases.

Removal of the part from the build plate

Optimise cutting parameters and compare different cutting strategies with Simufact Additive. Wire EDM and Bandsaw are two methods that are used for this. Note, that the different methods do not make any difference in the simulation.

If you do not have run any a heat treatment or if residual stresses are still present, those will disappear during the cutting process and will lead to further distortions. We advise you to consider cutting history during the simulation process because it always influences the part due to the non-linear material behaviour.

Simufact Additive offers several possibilities to simulate the cutting process of the parts from the base plate as well as the partial cutting of geometries for calibration purposes. In addition to the fast variation to solve all parts in the simulation simultaneously, you can also select predefined sections in x or y-direction at the desired height. If this is not enough, you can define any section concerning direction, length, and height in order to simulate complex section scenarios based on this.

Removal of the support structures

If the support structures are directly removed after the manufacturing process or if still, residual stresses remain in the part after the heat treatment process, the removal of the support structures can result in a new deformation and stress balance. Due to the non-linear material properties, this is in principle dependent on the sequence in which the support structures are removed, so that this can be considered in the simulation.

Comparison of simulation results with reference geometries

Simufact Additive allows comparing the simulated deformation of the component directly with the target geometry or with 3D measurement data as a reference. For this purpose, the user positions the simulation result and the reference part relative to each other. This step is performed either manually or automatically using the "best-fit method".

The visual representation of the results on the basis of the surface distances, based on metrological investigations, allows the user to quickly evaluate the results and immediately find out whether the deviations lie within the permissible tolerances.

Best-Fit method: By touch of a button compare simulation and reference model

With Simufact Additive, users can compare simulation results and reference model (e.g., CAD data) by mouse click using "best-fit" positioning. In the best-fit method, the software automatically determines the position at which the deviations are lowest.

The visual presentation of the results, based on measurements, allows the user to quickly assess whether the deviations are within the permissible tolerances.

For this function, Simufact has integrated Hexagon's 3DReshaper technology.

Comparison with physical tests

Comparison of the calculated parts with the target design or with 3D measurement data as a reference. The simulated deformations can be viewed relative to the reference geometry. Users measure the actual part and import it into Simufact Additive. This feature allows engineers to compare their results to ensure a more efficient workflow.