Engineering Physics Colloquium
Thursday, November 14
11:55 AM to 11:55 AM
106 Engineering Research Building
Speaker: Dr. Daniel Segalman, Sandia National Laboratories
"Modeling Joint Structures: They are Nonlinear and Difficult"
Abstract: The dynamics of built up structures – things put together with nuts and bolts, rivets, or other compression-type fittings – are demonstrably nonlinear. In our quest to obtain predictive models for structures, we are driven to account for that nonlinearity in our models. This move toward reproducing observable physics in our models presents several serious challenges: 1. Devising models for joint mechanics that are consistent with laboratory experiments on both full structures and on individual joints. 2. Incorporating those joint models into structural models. 3. Formulating those models so that they are computationally tractable. Much has been accomplished in each of these issues in the last decade, and much of that progress is due to the Joints Research Team at Sandia National Laboratories. Though still primitive, these technologies substantially advance the predictive capability of dynamics of real structures. Of particular focus in this talk are the numerical difficulties that arise as greater fidelity joint models are employed and a novel method of model reduction that mitigates some of this difficulty.
Biography: Dan Segalman is a Distinguished Member of Technical Staff at Sandia National Laboratories, where he has been since 1986. In that time he has worked in a wide variety of topics including the geo-mechanics of salt domes for the Strategic Petroleum Reserve, laser welding, aging of rubber components, mechanics of polyelectrolyte gels, and nonlinear vibrations and vibration of rotating structures. Most recently he has been working on uncertainty quantification (UQ) and quantification of margin and uncertainty (QMU). Prior to coming to Sandia, Dr. Segalman performed research in reservoir simulation and in geo-mechanics at Atlantic Richfield Production Research Laboratories. Prior to that he studied tire mechanics at General Motors Research Laboratory. Dr. Segalman earned his PhD in Engineering Mechanics from the University of Wisconsin, Madison.