The strength of the material is usually tested by using dedicated testing machines on which tensile tests are carried out. A small test object is subjected to great force until it breaks or breaks. The force projected on the part divided by the fracture center area at the moment of fracture expresses its force. However, engineers at UltiMaker, Covestro and the Royal Dutch Navy decided to take an unconventional approach to test beyond doubt how strong 3D printed parts can be? The Royal Dutch Navy has proposed … an armored vehicle!
In order to lift a heavy vehicle with a 3D-printed part, engineers first had to analyze the equipment. The Royal Dutch Navy had a specialist hoist at its disposal which used two openable steel rings to connect to the crane and ropes attached to the lifted vehicle. To connect them, an elongated O-shaped link was created.
After importing the geometry of the steel rings into the CAD software, UltiMaker application engineer Lars De Jongh created the initial joint design. For the design to work, the link required a flat side to achieve a stable 3D print and had to be printed with the ply lines in the same direction as the forces projected onto the part. The interacting surface of the part and the metal rings had to be as large as possible to distribute the forces evenly.
Engineers needed an extremely strong material that could absorb short-term peak forces. In the end, Covestro’s Addigy F1030 CF10 filament met the requirements. It is a polyamide-based polymer doped with carbon fiber and can be printed with desktop-class 3D printers – UltiMaker decided to use its device model – S5 for this.
Before a heavy vehicle could be lifted, engineers had to physically verify the calculated strength of the part. Two designs for two sizes were generated. The first was a 1 kg link, estimated at 12 tons. The second, weighing nearly 3 kg, was estimated at 38 tons. The tests were carried out with a stationary industrial tensile tester belonging to the Navy, which is capable of imposing a force of up to 343 kilonewtons on the object.
The difference between the tested results and the simulated values was close, on average only by 1%. This made the workflow accurate and cost effective in terms of time to market and increased productivity. After a few months of designing, 3D printing, testing and planning, it’s time to act. A Leopard 2 “Buffalo” equipped with a crane was used to lift the vehicle, which is designed to recover heavy vehicles such as trucks and battle tanks.
In the beginning, the link was used to lift a military version of a Mercedes jeep weighing more than two tons. This vehicle was easily lifted.
A two-kilogram carbon fiber reinforced link was then placed between the M113 armored tank and the Buffalo. The metal rings were clamped in place and four cables were attached to the vehicle from the lower hook to the vehicle. The 12-tonne vehicle was slowly lifted, suspended on a 3D-printed link. Buffalo then moved in different directions, and the link was perfect.
The entire operation can be viewed in the video below:
Source: www.ultimaker.com
Photos: www.ultimaker.com (press materias / all rights reserved)
