报告一：Hamel's Equations for Infinite-Dimensional Mechanical Systems
报告人: Dmitry V. Zenkov 教授
Department of Mathematics, North Carolina State University
时  间：5月13日(周五)下午2:30
地  点：力学楼314
主持人：刘才山 教授

内容简介：
Hamel's formalism is probably the most flexible version of Lagrangian mechanics. It is known for its effectiveness in the analysis of dynamics of systems with constraints and multibody systems. This talk will trace the origins of Hamel's formalism to the results of Euler and Lagrange. Next, recent results on the extension of Hamel's formalism to infinite-dimensional mechanics will be presented. Applications to the dynamics of solids with constraints will be discussed. This is a joint work with Donghua Shi (BIT), Anthony Bloch (University of Michigan), and Yakov Berchenko-Kogan (MIT).

报告人简介：
Dmitry V. Zenkov, Professor of the department of mathematics at North Carolina State University, received his Ph.D degree from the Ohio State University in 1998. He was the author or co-author of more than 80 research papers. Dr. Zenkov’s research has been focused on the dynamics of nonholonomic systems. He is severing as the members of editorial board for the Journal of Nonlinear Science, SIAM Journal on Control and Optimization, and Journal of Geometric Mechanics.
 
 
报告二：Multi-body Modeling and Dynamics for the Spacecraft with
Large Amplitude Liquid Sloshing
报告人: 岳宝增 教授
（北京理工大学 宇航学院）
时  间：5月13日(周五)下午3:30
地  点：力学楼314
主持人：刘才山 教授

内容简介：
Sloshing is the occurrence of any free liquid surface motion inside a container. For linear planar liquid motion, one can develop equivalent mechanical models in the form of a series of mass-spring dashpot systems or a set of simple pendulums. This talk focuses on the multi-body modeling method for the large amplitude liquid sloshing dynamics. The liquid slosh dynamics is included by using an improved moving pulsating ball model. The moving pulsating ball model (MPBM) is an equivalent mechanical model that is capable of imitating the whole liquid reorientation process, especially for large amplitude slosh. This model is improved by incorporating a static capillary force and an effective mass factor. This improvement is validated with the previously published experiment results. For a spacecraft with two liquid propellant tanks, the liquid slosh dynamics is included by using the improved MPBM. For the two tank system, two kind of eccentric cases of concern are 1) an asymmetric tank arrangement when the axis of maximum MOI of symmetry of dry spacecraft displaces away from desired geometric position and 2) an unbalanced propellant mass distribution in the two tanks. The feedback control strategy is proved to be efficient and robust for the coupled liquid filled spacecraft system. The effects of the two eccentric cases on sloshing torque and control torque are investigated. Some conclusions obtained in this paper are useful in the overall design of liquid filled spacecraft.

报告人简介：
YUE Baozeng, Professor of the School of Aerospace Engineering at Beijing Institute of Technology, received his Ph.D degree from the Tsinghua University in 1998. He was the author or co-author of more than 80 research papers, and has published one book on nonlinear liquid sloshing dynamics. Dr. YUE Baozeng is the member of Committee for Dynamics and Control, Chinese Society of Theoretic and Applied Mechanics.

 
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