Summary:
Additive manufacturing (AM) techniques (such as selective laser sintering, stereolithography, direct metal laser sintering, and others) enable the fabrication of parts with complex, freeform, internal and external architectures. We are exploring opportunities for leveraging this design freedom to enhance the functionality of structures. Functional roles include lightweight stiffness, strength, and compliance; impact, energy, or acoustic absorption; and heat exchange or insulation. Two applications include the design of energy absorbing materials and structures and the design of acoustic metamaterials. The energy-absorption project, for example, involves topology design and experimental validation of networks of energy-absorbing structures that exploit bistable or negative stiffness behavior to provide combinations of high stiffness for load-bearing and high damping for dissipation of acoustic and mechanical impacts and vibrations.
We are also engaged in developing designer's guides for AM. You can access some of our work here: http://designforam.me.utexas.edu/
Collaborators:
Michael Haberman, UT Austin, Applied Research Laboratories
Desi Kovar, UT Austin
Preston Wilson, UT Austin
David Bourell, UT Austin
Sandia National Laboratories
HRL Laboratories
Funding:
Sandia National Laboratories, DARPA (Structural Logic program), Cameron, NSF, America Makes, Army Research Lab, NSF
Related Publications:
Energy-Absorbing Structures, Cellular Structures, and Materials Design
Cortes, S. N. Cobo-Losey, M.R. Haberman, C.C. Seepersad, D. Kovar, 2021, “Stiffness and Energy Dissipation of Polymer Matrix Composites Containing Embedded Metallic Negative Stiffness Structures,” Experimental Mechanics, Vol. 61, pp. 843-858.
Morris, C., L. Bekker, C. Spadaccini, M. Haberman, C.C. Seepersad, 2019, “Tunable Mechanical Metamaterial with Constrained Negative Stiffness for Improved Quasi-static and Dynamic Energy Dissipation,” Advanced Engineering Materials, Vol. 21, No. 7, p. 1900163.
Morris, C., J. Cormack, M.R. Haberman, M. Hamilton, C.C. Seepersad, 2018, “Ultrasonic Characterization of the Complex Young’s Modulus of Polymer Parts Fabricated with Microstereolithography,” Rapid Prototyping Journal, Vol. 24, No. 7, pp. 1193-1202.
Morris, C., L. Bekker, M.R. Haberman, C.C. Seepersad, 2018, “Design Exploration of Reliably Manufacturable Materials and Structures with Applications to Negative Stiffness Metamaterials and Microstereolithography,” Journal of Mechanical Design, Vol. 140, No. 11, pp. 111415 (14 pages).
Debeau, D., C.C. Seepersad, M.R. Haberman, 2018, “Impact Behavior of Negative Stiffness Honeycombs,” Journal of Materials Research, Vol. 33, No. 3, pp. 290-299.
Cortes, S., J. Allison, C. Morris, M.R. Haberman, C.C. Seepersad, D. Kovar, 2017, “Design, Manufacture, and Quasi-static Testing of Metallic Negative Stiffness Structures within a Polymer Matrix,” Experimental Mechanics, in press.
Matthews, J., T. Klatt, C.C. Seepersad, M.R. Haberman, and D.W. Shahan, 2016, "Hierarchical Design of Negative Stiffness Metamaterials Using a Bayesian Network Classifier," Journal of Mechanical Design, Vol., 138, No. 4, p. 041404 (12 pages).
Correa, D.M., C.C. Seepersad, M.R. Haberman, 2015, “Mechanical Design of Negative Stiffness Honeycomb Materials,” Integrating Materials and Manufacturing Innovation, Vol. 4, No. 1, pp. 1-11.
Correa, D.M., T.D. Klatt, S.A. Cortes, M.R. Haberman, D. Kovar, and C.C. Seepersad, 2015, “Negative Stiffness Honeycombs for Recoverable Shock Isolation,” Rapid Prototyping Journal, Vol. 21, No. 2, pp. 193-200.
Fulcher, B.A., D.W. Shahan, M.R. Haberman, C.C. Seepersad, P.S. Wilson, 2014, “Analytical and Experimental Investigation of Buckled Beams as Negative Stiffness Elements for Passive Vibration and Shock Isolation,” Journal of Vibration and Acoustics, Vol. 136, No. 3, p. 031009 (12 pages).
Matthews, J., T. Klatt, C.C. Seepersad, M.R. Haberman, and D.W. Shahan, 2013, "Hierarchical Design of Composite Materials with Negative Stiffness Inclusions Using a Bayesian Network Classifier," ASME IDETC Design Automation Conference, Portland, Oregon, Paper Number: DETC2013-13128.
Klatt, T., M. Haberman, and C.C. Seepersad, 2013, "Selective Laser Sintering of Negative Stiffness Mesostructures for Recoverable, Nearly-Ideal Shock Isolation," Solid Freeform Fabrication Symposium, (D. L. Bourell, J. J. Beaman, R. H. Crawford, H. L. Marcus, and C. C. Seepersad, Eds.), Austin, TX.
Klatt, T., M.R. Haberman, D.W. Shahan, and C.C. Seepersad, 2012, "Hierarchical Modeling and Design of Composite Materials with Negative Stiffness Inclusions," Society of Engineering Science, 49th Annual Technical Meeting, Atlanta, GA.
Shahan, D., B. Fulcher, C.C. Seepersad, M.R. Haberman, and P.S. Wilson, 2011, "Robust Design of Negative Stiffness Elements Fabricated by Selective Laser Sintering," Solid Freeform Fabrication Symposium, (D. L. Bourell, J. J. Beaman, R. H. Crawford, H. L. Marcus, and C. C. Seepersad, Eds.), Austin, TX.
Kashdan, L., C.C. Seepersad, M. Haberman, and P. Wilson, 2012, "Design, Fabrication, and Evaluation of Negative Stiffness Elements Using Selective Laser Sintering," Rapid Prototyping Journal, Vol. 18, No. 3, pp. 194-200.
Panchal, J., D.L. McDowell, H.-J. Choi, C.C. Seepersad, J.K. Allen, F. Mistree, 2010, Integrated Design of Multiscale, Multifunctional Materials and Products, Elsevier (Butterworth-Heinemann), Burlington, MA. (Available on Amazon.com)
Seepersad, C. C., J. K. Allen, D. L. McDowell and F. Mistree, 2008, "Multifunctional Topology Design of Cellular Material Structures," ASME Journal of Mechanical Design, Vol. 130, No. 3, pp. 031404-1-13.
Seepersad, C.C., J. K. Allen, D. L. McDowell, and F. Mistree, 2006, "Robust Design of Cellular Materials with Topological and Dimensional Imperfections," ASME Journal of Mechanical Design, Vol. 128, No. 6, pp. 1285-1297.
Seepersad, C. C., B. M. Dempsey, J. K. Allen, F. Mistree and D. L. McDowell, 2004, "Design of Multifunctional Honeycomb Materials," AIAA Journal, Vol. 42, No. 5, pp. 1025-1033.
Designer's Guides for Selective Laser Sintering
Allison, J., Sharpe, C. and Seepersad, C.C., 2019, “Powder Bed Fusion Metrology for Additive Manufacturing Design Guidance,” Additive Manufacturing, Vol. 25, pp.239-251.
Allison, J., C. Sharpe, C.C. Seepersad, 2017, “A Test Part for Evaluating the Accuracy and Resolution of a Polymer Powder Bed Fusion Process,” Journal of Mechanical Design, in press.
Seepersad, C.C., T. Govett, K. Kim, M. Lundin, D. Pinero, 2012, "A Designer's Guide for Dimensioning and Tolerancing SLS Parts," Solid Freeform Fabrication Symposium, (D. L. Bourell, J. J. Beaman, R. H. Crawford, H. L. Marcus, and C. C. Seepersad, Eds.), Austin, TX.
Telenko, C. and C.C. Seepersad, 2012, "A Comparison of the Energy Efficiency of Selective Laser Sintering and Injection Molding of Nylon Parts," Rapid Prototyping Journal, Vol. 18, No. 6, pp. 472-481.
Deployable Structures
Maheshwaraa, U. and C.C. Seepersad, 2011, “Topology Design and Freeform Fabrication of Deployable Structures with Lattice Skins,” Rapid Prototyping Journal, Vol. 17, No. 1, pp. 5-16.
Maheshwaraa, U., C. C. Seepersad and D. L. Bourell, 2007, "Design and Freeform Fabrication of Deployable Structures with Lattice Skins," Rapid Prototyping Journal, Vol. 13, No. 4, pp. 213-225.