应航天航空学院机械结构强度与振动国家重点实验室邀请，比利时列日大学 (University of Liège) 航空与机械工程系、空间结构与系统实验室主任K. Kerschen教授前来我校进行学术交流。他将就在非线性模态在机械系统动力学、航天结构非线性振动的识别、仿真和设计、非线性利用与剪裁方法，以及在航天航空结构中应用等领域的研究成果与实验室开展学术交流，期间做学术报告两次。
学术报告安排如下：
一、题目：Resonances of nonlinear mechanical systems: a nonlinear normal mode perspective
报告时间： 2018年10月22日（星期一） 下午14：30—16：00
二、题目： Nonlinear vibrations of aerospace structures: identification, simulation and design
报告时间： 2018年10月24日（星期三）上午8：30—9：50
报告地点： 教学一楼南（二层） 第二会议室
航天航空学院
机械结构强度与振动国家重点实验室
2018年10月18日
报告人 简介：
Gaëtan Kerschen completed his Ph.D. degree in Aerospace Engineering from the University of Liège in Belgium in 2003. In 2003 and 2004, he was a visiting postdoctoral fellow at National Technical University of Athens and at the University of Illinois at Urbana-Champaign. Since 2007, he has been a faculty member at the University of Liège, where he is a professor in the Department of Aerospace and Mechanical Engineering. His expertise is primarily in the area of structural dynamics and orbital mechanics. He is the recipient of two European Research Council (ERC) grants, namely an ERC Starting Grant and an ERC Proof of Concept Grant. He was one of the principal investigators of the OUFTI-1 nanosatellite launched by the Soyuz rocket in 2016. He is the co-founder of NOLISYS, a startup company which provides solutions and software for nonlinear vibrating systems.
报告内容 简介
Resonances of nonlinear mechanical systems: a nonlinear normal mode perspective
The concept of resonance is central in structural dynamics, because the maximum amplitude at which a system or a product vibrates occurs at resonance frequencies. Unlike linear systems, nonlinear systems can exhibit different types of resonances including fundamental, internal or isolated resonances. In this presentation, we show how nonlinear modal analysis, and, specifically, the numerical computation of nonlinear normal modes, can be exploited for uncovering and understanding nonlinear resonances.
Nonlinear vibrations of aerospace structures: identification, simulation and design
The aerospace industry faces rapidly increasing technological, economic and environmental pressures. As a result, nonlinearities originating from, e.g., contact, friction, materials and large-displacement-related effects are more and more frequently encountered in aircraft and satellites. In this presentation, we introduce rigorous nonlinear generalizations of key linear concepts such as vibration modes, resonance frequencies, frequency response functions and the Fourier transform. Then, we show how these concepts lead to a profound understanding of the impact of nonlinearities on system’s dynamics, which includes frequency-energy dependence, bistability, modal interactions and quasiperiodic oscillations. A F-16 aircraft and an Airbus Defense and Space spacecraft serve to demonstrate that the proposed framework can be applied to large-scale aerospace structures.
