Advanced manufacturing and design present many unique solutions to existing issues. Whether it is through the creation of items formerly too cost-prohibited to be viable, or as a new way to visualize a design, this technology and its impact on many industries has created new ways to innovate. Yet its use is still somewhat limited.
A recent example of the fantastic work being done in the field is the virtual twin project being conducted by the National Institute for Aviation Research (NIAR), located at Wichita State University. The project, which is in large strokes the digitization of older U.S. Department of Defense aircraft, presents engineers the opportunity to experiment with and innovate on existing designs in a virtual environment.
This work will help sustain older aircraft, making part replacement more convenient and extending the life of the fleet. Virtual twins can help create a simpler avenue for replacement parts through 3D printing, or they can be the first step towards in-theatre manufacturing. All of this means that military platforms, vehicles, and weapon systems can be inactive for a shorter period of time.
GovDesignHub reached out and was able to speak with Dr. Melinda Laubach-Hock, NIAR Director of Sustainment, who kindly shared some insights into the program, what it takes to create a virtual twin, and what she believes is the future of the program and for advanced manufacturing and the design itself.
GovDesignHub (GDH): Can you tell our readers a little bit about NIAR? What is its mission and what is its relationship with Wichita State University? What role do students play in the work NIAR does?
Dr. Melinda Laubach-Hock: The National Institute for Aviation Research (NIAR), located in Wichita Kansas, operates as a not-for-profit R&D department of Wichita State University. Since its inception in 1985, NIAR has made a name for itself as the most capable university-based aviation research center in the United States, providing research, design, testing, certification, and training to the aerospace and manufacturing industries, the Federal Aviation Administration (FAA), the National Aeronautics and Space Administration (NASA), the Department of Defense (DoD), all branches of the Armed Forces, and defense contractors.
The services provided range the entire life span of an airframe, from initial concept to end of useful life. NIAR operates out of six major facilities in Wichita, Kansas with 1.3 million square feet of research space; 875 engineers, scientists, mechanics, inspectors, and technicians; and an annual operating budget of $125 million.
NIAR is not a typical university research institute; with hundreds of staff who do not teach in a classroom but work integrally with students in an applied learning model. Wichita State students are involved in applied research programs, working alongside experienced engineers and scientists. Students are exposed to the latest technological solutions and equipment and training, allowing them to easily enter the workforce as highly skilled professionals upon graduation.
GDH: What is a virtual twin? How does one go about creating a virtual twin for an aircraft that is 30 or more years old?
Dr. Melinda Laubach-Hock: The definition of a virtual twin varies significantly across published literature, but the definition NIAR uses is as follows:
“A multi-physics driven digital representation of a physical asset that predicts its dynamic behavior, performance, maintenance, and sustainment metrics, by integrating and synchronizing real-time and simulation data via data science techniques.”
The virtual twin process is largely the same for post-production airframes, regardless of age. Development of any virtual twin begins by gathering all of the engineering and technical data available for the specific airframe including drawings, 3D models, ground, and flight test data, fleet operation, and damage records.
For legacy airframes, the degradation of these documents is common – to the extent where a physical airframe is often required to confirm and/or fill in the gaps in the technical data. The process developed by NIAR involves two phases: a geometric virtual twin development and an engineering virtual twin development. Geometric twin development involves precision disassembly of an airframe to isolate detail parts; removal of paint, primer, and sealant; high-fidelity scanning to generate a point cloud representation of the geometry; and generation of manufacturing-quality CAD models from engineering data augmented with scan data to fill in gaps. All of the detail part CAD models are then digitally reassembled to the air vehicle level.
The engineering twin often consists of global finite element models or computational fluid dynamic models that represent how the virtual air vehicle will respond to environmental effects, external loads, and flight maneuvers.
GDH: Why is it important that we can manufacture parts for these military vehicles, platforms, and weapons systems with advanced manufacturing techniques like additive and subtractive manufacturing? How does that allow us to extend their life?
Dr. Melinda Laubach-Hock: In September 2018, the United States Government Accountability Office published a study on sustainment challenges affecting selected Air Force and Navy fixed-wing aircraft, which identified several reasons mission readiness was below goal. Part obsolescence and diminishing manufacturing sources were identified as issues that negatively affected the readiness of many of the airframes studied.
For this report, part obsolescence is defined as a part that is unavailable due to its lack of usefulness or is no longer current or available for production. Diminishing manufacturing sources is defined as a loss or impending loss of previously identified manufacturers or suppliers. Parsing the data even further, the non-existence of a digital 3D model is one of the primary reasons part requests are delayed or unfilled each year. Large manufacturers do not see a return on investment for manufacturing low quantity parts, particularly those that must be manufactured from original 2D drawings.
As the retirement dates for many military airframes continue to slide into the future and operators expand their mission profiles, spare parts become more and more critical to mission readiness. We are using our military inventory for different missions than previously designed and using them significantly longer than originally envisioned.
For these reasons, the demand for spare parts has also grown to play a larger role in depot maintenance than previously anticipated. The development of manufacturing quality 3D models opens up the supplier base and encourages more competition in the replacement part business for both traditional subtractive manufacturing (conventional machining) and additive manufacturing (3D printing). Additive manufacturing, when applied to an appropriate subset of parts, also shows promise as a reliable tool to address the lack of spare parts.
GDH: Are virtual twins capable of enabling more than 3D printing or subtractive manufacturing of an out-of-production part? Can they play a role in predictive and preventative maintenance?
Dr. Melinda Laubach-Hock: The VirtualTwin technology is capable of far more than solely addressing spare parts issues. For many legacy airframes, high-fidelity engineering models either do not exist or are not available for government usage. The purpose of the engineering twin is to develop high fidelity engineering models including computational fluid dynamics (CFD), global finite element models (GFEM), and detailed finite element models (DFEM) to predict and understand the response of the physical airframe to operational loads.
The development of a GFEM, for example, allows the operator to predict internal stresses on parts based on the loading applied to the airframe. Therefore, if a mission requirement changes, the effect on the airframe can be assessed before the mission being executed in the fleet. These tools allow operators to identify potential areas of failure proactively.
A comprehensive Digital Engineering environment also provides a single repository for fleet data. Historically operators collect a significant amount of data regarding the condition of the fleet, but often it is not organized and presented in a manner where trends are easily identified.
GDH: As someone working closely with the military on these projects, how widely adopted – would you say – are these technologies across the DoD? Is the adoption of advanced manufacturing still in its infancy? If so, what has to happen for this to gain wider adoption?
Dr. Melinda Laubach-Hock: Digital Engineering is relatively new to everyone, including the military. I believe the DoD sees the potential of widespread usage of the technology, but the comprehensive development of a full Digital Engineering environment will take time, consistent technical direction, and a consistent revenue commitment.
To maximize the impact of advanced manufacturing, a weapons system would need a fully developed digital engineering environment to understand the manufacturing choices’ technical engineering implications.
GDH: What’s next for NIAR and the Virtual Twin? Are there any exciting new projects on the horizon that you’re willing to share with our readers?
Dr. Melinda Laubach-Hock: NIAR is currently developing two new Digital Engineering programs with the Air Force. Unfortunately, details of those programs cannot be shared publicly at this time. Expect announcements on these programs early summer timeframe.