FEA Analysis and Predicting the Performance of 3D Printing

Although it has been around for about 30 years, 3D printing is still a new technology, particularly when it comes to the mechanical properties of 3D-printed parts. Given the geometric complexity of components possible with 3D printing, including lightweight internal geometries, 3D-printed objects may perform better or worse than their traditionally manufactured counterparts. Therefore, it may be necessary to use digital tools that can predict how a 3D-printed part will perform in the physical world.

3D Matter is a unique firm that has been working to fill in the knowledge gaps associated with 3D printing. Beginning as a consultancy, it analyzed various 3D printing filaments and made comparisons, determining which materials outperformed the rest. More recently, however, 3D Matter has ventured into the world of software design, releasing OptiMatter, a SaaS that allows users to compare various materials and printing parameters and analyze the mechanical properties of the 3D-printed output.

Now, 3D Matter has taken its work a step further as it embarks on finite element analysis (FEA) for 3D-printed parts. FEA enables engineers to mathematically model the behavior of physical objects, including how a material will behave under stress. 3D Matter has begun developing a proprietary methodology for applying FEA to 3D-printed parts, which may differ from traditionally manufactured parts in terms of the weak adhesion of vertical layers, a wide variety of printing parameter variables and the behavior of the outer surface, which will perform differently than the interior geometry.

Injection-molded and 3D-printed PLA objects are first modeled undergoing a 500Kg load. (Image courtesy of 3D Matter.)

To demonstrate the possibilities, 3D Matter has conducted static linear FEA on a model of a stool that would be manufactured in polylactic acid (PLA), comparing injection molded PLA to 3D-printed PLA, and applying a frictional force of 500 kg to it. The results showed that the injection molded stool would survive the weight easily, while the 3D-printed counterpart had significant weak points throughout.

The stress of the load is predicted with FEA. (Image courtesy of 3D Matter.)

One important reason for the weakness, according to 3D Matter, was the 3D printing parameters for the stool. While the outer surface of the object was predicted to hold up under the weight, the infill of the model was too weak and would need to be adjusted appropriately if one were to actually print the object (and put a significant load on it).

The weakness under the load is determined to be associated with the 3D printing parameters. (Image courtesy of 3D Matter.)

Although 3D Matter has not yet tested the results of its 3D-printed stool, it has performed empirical analysis of smaller 3D prints that confirm a close enough match between FEA predictions and the actual displacement of a part and its behavior under stress.

A 3D-printed hook and the FEA analysis of a model of the hook are compared, revealing accurate predictions. (Image courtesy of 3D Matter.)

Whether or not 3D Matter will ultimately incorporate its FEA tools into future versions of OptiMatter is unclear, but, for the time being, those looking for an FEA analysis report on a specific file can obtain one by filling out this order form at 3D Matter's website.