21st Century Paradigm Change in Performance and Design Metrics Proceedings of a Workshop (2019) / Chapter Skim
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2 Modeling Frameworks That Fit the Defense Materials, Design, and Manufacturing Tradespace
2 Modeling Frameworks That Fit the Defense Materials, Design, and Manufacturing Tradespace
Pages 13-44
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From page 13... ...
Collopy believes that the change involves the materials and manufacturing communities in important ways. He shared that the SERC has made great progress in the past 6 years, producing papers, research, and outcomes of great interest to the broader community.
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From page 14... ...
. However, additive manufacturing complicates this process because it allows the creation of functionally graded materials that can change from one material on one side of a part to another material on the other side, Collopy explained.
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From page 15... ...
Collopy agreed that this is an important issue and has been an important issue for the past 60 years; however, engineers lack sufficient training to understand and address social science problems. In order to truly improve systems engineering processes, Collopy asserted, social scientists with expertise in organizational behavior must be brought into the conversation; statistics alone will not solve this problem.
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All involved in the design process and the supply chain need to be informed of trade factors (e.g., weight and cost) and how they affect the outcome in order to develop successful products.
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Models generated from this process can then be used to develop solutions: mathematical optimization allows big data to be evaluated to better inform seniorlevel decision makers. With all of these new tools, Goerger explained, ERS tries to create an open architecture to bring diverse components together to enhance the acquisition process, as opposed to adding another layer to the acquisition process.
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An additional goal for 2016 was to insert initial life cycle cost modeling into the decision-making process. This type of modeling is compli cated and sensitive, Goerger explained, just like the sharing of performance data.
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From page 19... ...
It is a serious and costly problem if a system lasts only one year because of environmental factors or other systemic factors. This is why additive manufacturing plays an important role: it can be used in an operational environment to produce spare parts, as was also suggested by Paul Collopy.
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issue, Goerger explained that the person developing an IP is responsible for protecting it; these tools simply create an environment within which to work. Kern followed up with a concern about the role of suppliers: even though suppliers own rights to materials, they do not seem to be included in the system.
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WHY NOT BOTH? Steve Cornford, Senior Engineering, System Modeling and Analysis Program Office, NASA Jet Propulsion Laboratory Steve Cornford opened his presentation by emphasizing the difficulties inherent in prediction.
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From page 22... ...
Cornford explained that the goal is to launch only the pieces that should be replaced, and doing this requires much thought about the production lines, supply chain, and learning curve, for example. Cornford noted that because of time and scope constraints, not all factors (e.g., weather, cyber ecurity, etc.)
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From page 23... ...
DBATI Costs, Launch Costs PSV Calculator and Operations Costs ModelCenter® Accumulator Integrated Present Strategic Value, NPV, Embedded Real Option Values, Other IVMs and OVMs Outputs 1 FIGURE 2.2 Threads of calculation model. SOURCE: Steve Cornford, NASA Jet Propulsion Laboratory, presentation to the workshop.
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From page 24... ...
Cornford noted that his team never attempted to build a universal uncertainty model; instead, they opted for a user-focused, customizable model based on a mission's particular needs, values, and tolerance for risk. ASDA has now been in existence for over 3 years and was just the start of JPL's innovative work in this area.
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From page 25... ...
Kobryn asked how business is transformed when the odds of being successful change, and she also asked if any evidence of the benefits exists. Cornford noted that documentation currently exists for pieces of it, but not yet for the whole.
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Reconfigurable manufacturing systems (RMS) combine the advantages present in both the dedicated manufacturing systems and the flexible manufacturing systems.
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It is important to note that setting up RMS requires much work at the onset, including life cycle cost analysis to justify additional initial costs and ensure future cost recovery. The process of doing this can be complicated, Ulsoy noted.
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From page 28... ...
9529125 NSF Engineering Research Center for Reconfigurable Machining Systems 5 University of Michigan College of Engineering Comparison:
Three Types of Basic Systems Dedicated RMS/RMT FMS/CNC System Structure Comparison:
Fixed Adjustable Adjustable Three Types of Fixed Machine Structure Basic Systems Adjustable Fixed System Focus Part Part Family Machine Flexibility Dedicated No RMS/RMT Customized FMS/CNC General System Structure System Scalability Fixed No Adjustable Yes Adjustable Yes Machine Structure Machine Scalability Fixed No Adjustable Yes Fixed No System Focus Simultaneous Part Part Family Machine Yes Yes No Operating Tools Flexibility No Customized General System Scalability NoAdjustable structure, customizedYes • Yes flexibility, and scalability create responsive systems Machine Scalability No Yes No • Part Family focus and simultaneous Simultaneous operating tools create cost-effective systems Part Family Yes Yes No Operating Tools NSF Engineering Research Center for Reconfigurable Machining Systems 6 University of Michigan College of Engineering FIGURE 2.3 The benefits of reconfigurable manufacturing systems outweigh the benefits of flexible • Adjustable structure, customized flexibility, manufacturing systems and dedicated manufacturing systems.responsive systems Ulsoy, University of and scalability create SOURCE: A Galip • Part Family focus and simultaneous Michigan, presentation to the workshop.operating tools create cost-effective systems Part Family NSF Engineering Research Center for Reconfigurable Machining Systems 6 University of Michigan College of Engineering be included in a cost model.
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From page 29... ...
Ulsoy concluded by reiterating his central point: reconfigurable manufacturing allows designers to respond to environmental changes.
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AIRCRAFT DIGITAL THREAD: AN EMERGING FRAMEWORK FOR LIFE CYCLE MANAGEMENT Pamela Kobryn, Senior Aerospace Engineer, U.S. Air Force Research Laboratory Pamela Kobryn provided an overview of the role of AFRL, which develops science and technology for the Air Force in ways not always possible in the acqui sition environment.
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From page 31... ...
The Digital Twin, then, is an "integrated multiphysics, multiscale, probabilistic simulation of an as-built system enabled by Digital Thread."7 The Digital Twin is similar to an avatar that can forecast performance, no matter the environmental or operational circumstances. The Digital Twin, then, is a subset of the Digital Thread (i.e., a digital surrogate)
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From page 32... ...
SOURCE: Pamela Kobryn, U.S. Air Force, presentation to the workshop (Case # 88ABW-2016-3661)
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Digital Thread can help modernize and improve this process through the development of an analysis framework for Individual Aircraft Tracking. This program is called the Airframe Digital Twin (ADT)
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Simon Goerger then asked if the Airframe Digital Twin has been used for systems other than airframes. Kobryn said that this is happening with turbine engines, but that it is more difficult to translate into other realms because of the increase in vendors, and thus an increase in data.
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From page 35... ...
The third case was also about impedance properties of insulating materials; however, this case included a water adsorption component that changed the dielectric properties and conductivity of the material. Gerhardt pointed out that water adsorption characteristics are important to consider when using porous materials in a high-humidity environment, especially since the electrical behavior of materials shows a signature response as a function of frequency based on the environment the material is exposed to.
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From page 36... ...
This is why it is essential to consider the properties in many directions and to use a wide variety of methods. Gerhardt recommended the following procedure: • Establish a baseline electrical testing setup to obtain desired response for the materials system of interest; • Develop master curves for the parameters of interest; • Model the response using both equivalent circuits and electrical interface based microstructural modeling; • Corroborate models with complementary experimental characterization techniques to validate analysis; • Model the expected changes, considering environmental factors; and • Compare the changes to the predicted changes in order to develop new models.
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From page 37... ...
PANEL DISCUSSION: UNCERTAINTY AND CHANGE PROPAGATION IN MODELING Participants: Martin, Research Associate, Pennsylvania State University Jay Applied Research Laboratory Saigopal Nelaturi, Palo Alto Research Center Rosario A Gerhardt, Goizueta Foundation Chair and Professor, School of Materials Science and Engineering, Georgia Institute of Technology Pamela Kobryn, Senior Aerospace Engineer, U.S.
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From page 38... ...
This leads to both chal lenges and opportunities in the way that systems are designed because one can no longer assume that parts and design models follow an existing function. When con structing new models using additive manufacturing, Nelaturi said that one must conduct simulations on as-built parts, keeping in mind uncertainty in aterials m and manufacturing.
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From page 39... ...
Nelaturi explained that the paradigms are still evolving -- for example, topology optimization is beginning to improve additive manufacturing, but it may not work for all design processes. He noted that there is an opportunity for product life cycle managers (for example, businesses using Digital Thread models)
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From page 40... ...
Cornford noted that engineers sometimes are correct in their lack of trust in math models. For example, the Voyager outlived its predicted life cycle by 15 years.
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Wadley compared a part developed through additive manufacturing to a part made in a traditional machine and asked if the life span of the additive manufacturing part would be lower as a result of existing cracks and fatigue life. Kobryn said that robust design may help overcome additive manufacturing challenges.
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Martin noted that this is the appropriate time to analyze the data to identify the cause of the problem: there may be correlated or direct effects. McGrath then referred to earlier discussion about the human factor in the decision-making process.
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Cornford noted that not all intuition is created equally, making it difficult to calibrate. Martin suggested that intuition is Bayesian in nature: Decisions are made based on past experience and current information, which is a difficult process to automate.
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From page 44... ...
A solution to this problem, he explained, would be to create a master model, like a Digital Twin, containing all of the information and having the capability for the representations themselves to communicate with one another. This could lessen the loss of information and the increase in uncertainty that happens when trying to make data conversions.
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