New, 3-D printer technology being developed by research engineers at the U.S. Army Research Laboratory (ARL) and Purdue University can aid Soldiers in remote locations to spot and fix damaged aircraft and ground vehicle parts. By combining finite-element analysis and structural optimization software, new possibilities in armor production and repair are enabled.
The researchers found that improvements in energy absorption and dissipation, productivity and maintenance costs could be realized. They use finite-element analysis software ABAQUS with Python, an open-source code used to optimize logical structures. Logical structures are tailor-made so as to allow for superior energy damping, load transfer, high stiffness, etc. Rather than simply using more material to improve component reliability, they use smarter design.
For armor applications, they suggest topologically interlocked structures (TISs). The software is used to assist designers with modeling the new generation of 3-D, additively manufactured TISs.
As described by Ed Habtour, a research engineer with ARL's Vehicle Technology Directorate, "The benefit for the Soldier is an after-effect. The TIS would provide an excellent energy absorption and dissipation mechanism for future vehicles using additive manufacturing. Subsequently, the Soldier can print these structures in the field using additive manufacturing by simply downloading the model generated by the designer/vendor."
Armor is meant to resist failure and to fail in a controlled manner when it does. It is typical to employ exotic materials to meet battlefield demands, but the testing and approval process for new materials is time-consuming. Logical materials can reduce cost and decrease response time.
The logical structure is based on principles of segmentation and assembly. The structure is segmented into independent, unit elements then assembled in an optimal orientation to enhance the overall properties of the structure. These segments are relatively small and have a complex shape. Perfect for 3-D printing.
"Sometime in the near future, Soldiers would be able to fabricate and repair these segmented structures very easily in the front lines or Forward Operating Bases, so instead of moving damaged ground or air vehicles to a main base camp for repair, an in-field repair approach would essentially mean vehicles would be fixed and accessible to warfighters much faster at lower costs," said Habtour. "We want to change the conventional thinking by taking advantage of exciting materials and manipulating the structure based on the principle of segmentation and assembly."
Rather than replacing large, expensive armor plates, the repair could be more localized. This can allow quicker turnaround of vehicles. Although the cost of repair and maintenance is cited to be lower, the upfront cost of getting the technology deployed and training Soldiers is significant. Whenever you “change the conventional thinking,” there is bound to be a battle ahead.