3D-printing impacts on systems engineering in defense industry

Today’s combat vehicle designs are largely constrained by traditional manufacturing processes, such as machining, welding, casting, and forging. Recent advancements in 3D-Printing technology offer tremendous potential to provide economical, optimized components by eliminating fundamental process limitations. The ability to re-design suitable components for 3Dprinting has potential to significantly reduce cost, weight, and lead-time in a variety of Defense & Aerospace applications. 3Dprinting will not completely replace traditional processes, but instead represents a new tool in our toolbox from both a design and a manufacturing standpoint. 3D-PRINTING DEVELOPMENT ACCELLERATES While the fundamental science has existed for decades, 3D-printing has gained incredible momentum in recent years for applications like rapid prototyping and is now being adopted for niche production applications. 3D-printing holds tremendous potential, but considerable challenges exist before this process can truly revolutionize the future of manufacturing. This paper highlights examples of how 3Dprinting is being used in Aerospace & Defense industries today, how it may be applied in the future, and what obstacles must be overcome before widespread applications become mainstream. From a business standpoint, the primary over-arching benefits that 3D-printing offers are related to economies of scale and scope, essentially increasing the variety of products a unit of Capital can produce. For this reason, 3Dprinting is particularly well-suited for the Defense and Aerospace industries thanks to its ability to produce multiple design iterations on a single machine setup. Like other organizations providing equipment to the US Armed Forces, GDLS constantly searches for innovative methods to improve performance, reduce lead time, and deliver meaningful value where it matters most. 3D-printing can undoubtedly contribute to these objectives, but fully realizing this potential will take strategic vision, technical innovation, and willingness to move beyond traditional process limitations. NEAR-TERM APPLICATIONS ABOUND While many people picture 3D-printing as a single technology, there are actually several unique processes that use distinctly different methods to build a component one layer at a time from a CAD model. A common process used today for the templates, prototypes, and tooling mentioned above is called Fused Deposition Modeling (FDM), which has gained popularity in recent years as 3D-printing of plastic parts evolves beyond traditional stereolithography. A wide variety of organizations currently use high-temp polymers for 3D-printing; dramatically reducing lead time and cost while enabling design freedoms not possible with traditional processes. From a Systems Engineering standpoint, the ability to quickly and easily 3D-print prototypes holds substantial promise in reducing design cycle time, comparing multiple design iterations, and optimizing overall packaging layout. This rapid prototyping capability enables design teams to identify issues early in the process and optimize component geometry for seamless integration. A variety of advanced polymers and similar materials for this type of 3D-printing have emerged in recent years, each with unique properties suited for particular applications. General Dynamics Land Systems (GDLS) has utilized FDM technology in a number of applications that illustrate the capability of 3D-printing to provide measurable efficiency gains without actually being used for production components. One example is a fit-check model for a radio that requires weeks of lead time to obtain. Since the design Proceedings of the 2015 Ground Vehicle Systems Engineering and Technology Symposium (GVSETS) Approved for public release, Log No. 2015-35, Distribution Unlimited, 07/06/2015 Page 2 of 6 team was only interested in how the radio integrated into the vehicle to identify any interference or access issues, the 3Dprinted plastic model of the radio satisfied all the objectives. This part went from CAD model to 3D-printed model in two days and prevented costly delay to the program schedule. Another recent example is a wiring harness connector that was on backorder, posing a program delay of several weeks. Instead of accepting this negative schedule impact, GDLS was able to quickly print plastic versions of the component and use them in place of the backordered item in an engine test application at over 350-degrees F. Not only is this an illustration of the rapid turnaround time that 3D-printing can deliver, but also shows that the engineered polymers being used in 3D-printing are robust enough to handle demanding conditions, such as this hightemperature test. Given the rapid manufacturing capability for FDM to create low-cost plastic components with optimized geometry, GDLS has investigated the possibility of incorporating a thin, high-strength structural metal cladding to be applied to a 3D-printed plastic component. This combination could offer performance similar to a metal component at a fraction of the weight, but would likely only apply to non-critical areas, such as brackets, etc. Extensive testing is necessary to better understand the long-term properties and failure modes of both the 3D-printed polymer core and the structural cladding. If this hybrid solution is proven to be a viable option, it opens up a number of possibilities for applying 3D-printed “semi-metallic” components for end item use in the near term. To further leverage the Systems Engineering benefits that 3D-printing can provide throughout the design process, GDLS has also developed sophisticated reverse-engineering capabilities that employ a 3D-scanning unit that can quickly capture the geometry of a physical part or assembly, convert it to a CAD model, and 3D-print as needed. Current applications at GDLS are using the scan data to 3D-print plastic parts for instances where CAD data is not readily available, but in the future this same capability can be used for metallic components as well. TREMENDOUS OPPORTUNITIES, SUBSTANTIAL CHALLENGES Applying 3D-printing for solid metallic components, on the other hand, presents a host of technical obstacles that are the focus of ongoing development efforts in industry, academia, and Government organizations. The primary challenge to qualifying 3D-printed metallic components for end-item production use, especially in Defense & Aerospace, is difficulty in controlling process inputs to achieve consistent outputs. Industry standards are being developed to regulate the composition and quality of raw materials used for 3D-printing, and similar efforts are underway to create a centralized database for materialspecific process parameters as well. This level of industry standardization is crucial to the advancement of 3D-printing in metal-based production applications, and is the focus of substantial research and development. These development initiatives are encouraging, but until they’re approved for broad use on Defense & Aerospace components, it’s impossible to qualify a component without conducting a detailed analysis of each individual part. 100% inspection would obviously be cost-prohibitive and limits to use of 3Dprinting metal components to niche applications. GDLS has committed substantial effort in recent years to better characterize how and when 3D-printing technology will impact the ground combat vehicle industry. Partnering with industry and academia, GDLS is pursuing 3D-printing production solutions in a variety of areas, with a prime example being part consolidation on complex welded components. Part consolidation, such as converting a multipiece weldment to a one-piece 3D-printed part, reduces complexity, production cost, and component weight. In addition, 3D-printing enables optimization of the design by Figure A: Radio hardware (above) and 3D-printed plastic fit-