Topic: 94th NIA CFD Seminar: Flexible Multibody Dynamics Tools For Rotorcraft Comprehensive Analysis
Date: Thursday, September 28, 2017
Time: 12pm-1pm (EST)
Room: NIA, Rm137
Speaker: Olivier A. Bauchau
Abstract: Flexible multibody dynamics techniques provide a framework for the dynamic analysis of aerospace vehicles in general and of rotorcraft, in particular. Dymore is a flexible multibody dynamics code that includes geometrically-exact beam elements, rigid bodies, kinematic joints, and modal elements. Through an integrated set of interface routines, Dymore enables the use of simple aerodynamic models but also allows the coupling of structural dynamics models with advanced CFD tools such as FUN3D or OVERFLOW. SectionBuilder is a finite element based tool that evaluates exact solutions of three-dimensional elasticity for beams of general cross-sectional shape made of anisotropic materials; the three-dimensional stress field at any point of the blade is a byproduct of these exact solutions. Rotor blade detailed design, structural integrity, fatigue life, and optimization all depend on the accurate knowledge of three-dimensional stress distributions.
Recently, a parallel version of Dymore has been developed by integrating three key techniques: (1) the motion formalism, which removes most kinematic nonlinearities from the governing equations of motion, (2) domain decomposition techniques that partition the system to exploit the reduced nonlinearities and (3) parallel computation is then a natural consequence of the independence of the sub- domains. Ongoing and future developments of Dymore and SectionBuilder will be presented; they include (1) the development of spectral solvers for the evaluation of periodic solutions for flexible multibody systems, (2) the development of discretely consistent adjoint-based sensitivity analysis, and (3) the development of nonlinear three-dimensional finite element modeling of rotorcraft structures based on the motion formalism.
Bio: Dr. Bauchau earned his B.S. degree in engineering at the Université de Liège, Belgium, and M.S. and Ph.D. degrees from the Massachusetts Institute of Technology. He has been a faculty member of the Department of Mechanical Engineering, Aeronautical Engineering, and Mechanics at the Rensselaer Polytechnic Institute in Troy, New York (1983-1995), a faculty member of the Daniel Guggenheim School of Aerospace Engineering of the Georgia Institute of Technology in Atlanta, Georgia (1995-2010), a faculty member of the University of Michigan Shanghai Jiao Tong University Joint institute in Shanghai, China (2010-2015). He is now Igor Sikorsky Professor of Rotorcraft in the Department of Aerospace Engineering at the University of Maryland.
His fields of expertise include finite element methods for structural and multibody dynamics, rotorcraft and wind turbine comprehensive analysis, and flexible multibody dynamics. He is a Fellow of the American Society of Mechanical Engineers, a Technical Fellow of the American Helicopter Society, and a senior member of the American Institute of Aeronautics and Astronautics. His book entitled “Flexible Multibody Dynamics” has won the 2012 Textbook Excellence Award from the Text and Academic Authors Association. He is the 2015 recipient of the ASME d’Alembert award for lifelong contributions to the field of multibody system dynamics.
Additional information, including the webcast link, can be found at the NIA CFD Seminar website: