21st Century Paradigm Change in Performance and Design Metrics Proceedings of a Workshop (2019) / Chapter Skim
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3 Changing the Design Paradigm
3 Changing the Design Paradigm
Pages 45-66
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From page 45... ...
Instead of relying on the traditional designs that are used primarily for their ease of manufacture, Guest explained, topology optimization "starts with a blank slate" and though the manufacturing process may become more complex, the improvements to the structure and use of resources are ultimately better. Guest next provided an example of designing a force invertor, utilizing topology optimization to find and manipulate the load path to maximize negative displacement.
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From page 46... ...
Similar to the force invertor example, the process begins with a uniform initial guess. The passive valve ultimately creates an obstacle that, because it is well shaped, manages the flow effectively in the desired direction, making it significantly easier to flow in one direction than another.
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From page 47... ...
Guest moved from this discussion at the component level to a discussion of material architecture and topology optimization through the use of existing material chemistries. Currently, designers pass a particular material through the topology optimization engine, with a particular objective in mind, and end up with an optimized material architecture that is dependent on the base material.
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From page 48... ...
Challenges that remain are in choosing appropriate manufacturing spaces and incorporating varied materials into one design engine. A long-term goal, currently in development, is to incorporate manufacturing flaws directly into the algorithms to increase robustness of designs or insensitivity to flaws.
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From page 49... ...
Guest hopes that this idea can be joined to a tool path and to costs in the future. EXTREME SCALE SIMULATION OF COMPLEX MATERIAL RESPONSE Raul Radovitzky, Professor, Department of Aeronautics and Astronautics, Massachusetts Institute of Technology Raul Radovitzky opened his presentation on modeling material failure by showing two images of a crack; he then asked the audience to determine which was a model and which was an experiment.
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From page 50... ...
Though Radovitzky's team has done parametric analysis, for example, there is still work to be done to improve validation methods. An additional challenge, Radovitzky explained, is the preservation of intact pieces in simulations, since the numerical methods used to shatter things is easier Seamless crack propagation across processor boundaries • Simulation of blast-loaded pre-notched RHA steel plates Collaboration with TARDEC J2 plastic, JC hardening Elastic material Discontinuous Galerkin – Cohesive Zone Models: first and only known scalable method for simulating fracture FIGURE 3.3 Seamless crack propagation across processor boundaries.
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From page 51... ...
Most of the digital approaches explored in Radovitzky's talk happen at the coupon component level; however, he has begun exploring modeling for larger structures. Often when there are small cracks in one section of a larger structure, this will cause problems throughout the structure.
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From page 52... ...
Johan de Kleer opened his presentation by providing an overview of his experi ences with qualitative physics, DARPA's Adaptive Vehicle Make program, and Xerox product manufacturing and design. De Kleer explained his frustration that current design tools cannot keep up with new materials, platforms, and systems, which prevents the realizaiton of possibilities.
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From page 53... ...
De Kleer presented three types of designers: insane, sane, and analogical. The insane designer completely exhausts the search space without receiving any feedback and continues to try various structures until finding one that exhibits the desired behavior.
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From page 54... ...
De Kleer acknowledged that these new systems generate new design questions: What kinds of design tools are needed? How homogeneous should the system be?
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From page 55... ...
Overall, Guest compared topology optimization to de Kleer's vision of the "sane designer" because it involves formal sensitivity analysis for design changes and physics-based language. De Kleer noted that designing languages is a difficult process.
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From page 56... ...
Begley noted that building a finite ele ment code may not be the best design strategy; new design tools are needed instead. Additionally, simulations should be done before experiments are done.
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From page 57... ...
However, successful design for material systems relies on the intersection of design theory, systems engineering, computer science, mechanical engineering, and materials science. Begley reminded participants that although virtual simulations can reduce time in the development cycle, choices must be made carefully and thoughtfully.
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From page 58... ...
Begley noted that one must consider time when contemplating the use of COMSOL multiphysics. McGrath revisited the workshop focus: 21st century paradigm change.
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From page 59... ...
However, because the Army represents a relatively small market, complex multimaterial manufacturing processes can introduce challenges associated with using expensive high technology in producing low-demand products. His Materials and Manufacturing Science Division executes integrated research in the following areas: emerging materials, soldier materials, 3 For more information about ManTech, see https://www.dodmantech.com/ManTechPrograms/ Army, accessed May 18, 2018.
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From page 60... ...
As part of the Army's ision, Cho highlighted that additive manufacturing can be one of the v manufacturing techniques used in adaptive manufacturing for the Army's perva sive applications. For example, technology readiness level (TRL)
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Lockheed Martin also used the "digital tapestry" that digitized the supply chain. However, Lockheed Martin's advanced manufacturing teams are coming up with ideas for original equipment manufacturers, but they
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Johnson emphasized the importance of developing integrated multifunction com ponents; he used integrated electronics as an example. He also suggested that design engineers need to be taught to design without manufacturing constraints, and that the design tools in place have to foster this.
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From page 63... ...
This can be done fairly quickly, according to Swink. McKnight noted that Virginia Tech 7 For more information about the T model for student learning, see http://groupcvc.com/ service-thinking/t-shaped-professionals/.
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In a best-case scenario, the digital tapestry would extend to the bottom of the chain and provide informa tion about material models. The actual situation, however, includes a proprietary global supply chain.
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From page 65... ...
McGrath asked McKnight to share more of Virginia Tech's experiences with cybersecurity and manufacturing. McKnight revealed that there are a number of vectors and a number of threats.
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From page 66... ...
De Kleer said that most advances in technology are in materials and that there is a disconnect between materials sciences and the physical design world. Gerhardt added that the reason for this is because there has been too much emphasis on the chemistry and the structure of materials in the research community; the way things are made controls everything.
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