New tool gives structural strength to 3D printed works
19 September 2012
Objects created using 3D printing have a common flaw: they are fragile and often fall apart or lose their shape, the printed fabrications often failing at points of high stress.
Bedrich Benes show some of the failed or misshapen objects of 3D printing (Purdue University photo/Mark Simons)
3D printers create shapes layer-by-layer out of various materials, including metals and polymers. Whereas industry has used 3D printing in rapid prototyping for about 15 years, recent innovations have made the technology practical for broader applications.
"Now 3D printing is everywhere," says Bedrich Benes, associate professor of computer graphics at Purdue University in Indiana, USA. "Imagine you are a hobbyist and you have a vintage train model. Parts are no longer being manufactured, but their specifications can be downloaded from the Internet and you can generate them using a 3D printer."
The recent rise in 3D printing popularity has been fuelled by a boom in computer graphics and a dramatic reduction of the cost of 3D printers, Benes said. Now, researchers at Purdue and Adobe's Advanced Technology Labs have jointly developed a program that automatically imparts strength to objects before they are printed.
"It runs a structural analysis, finds the problematic part and then automatically picks one of the three possible solutions," Benes said.
Former Purdue doctoral student Ondrej Stava created the software application, which automatically strengthens objects either by increasing the thickness of key structural elements or by adding struts. The tool also uses a third option, reducing the stress on structural elements by hollowing out overweight elements.
Not only are the objects structurally better, but they are much less expensive to make. The team has demonstrated weight and cost savings of 80 percent.
The new tool automatically identifies "grip positions" where a person is likely to grasp the object. A "lightweight structural analysis solver" analyses the object using a mesh-based simulation, requiring less computing power than traditional finite-element modelling tools.
"The 3D printing doesn't have to be so precise, so we developed our own structural analysis program that doesn't pay significant attention to really high precision," Benes said.
Future research may focus on better understanding how structural strength is influenced by the layered nature of 3D-printed objects. The researchers may also expand their algorithms to include printed models that have moving parts.