必威betway中文版学术报告
报告题目:
Grazing Induced Bifurcations: Innocent or Sinister?
报告人:
Professor Marian Wiercigroch
Centre for Applied Dynamics Research,School of Engineering,University of Aberdeen, UK
报告时间:
4月28日(周五)9:30
报告地点:
第七教学楼C210
报告摘要:
This lecture will argue the nature of subtle phenomenon such grazing bifurcations occurring in non-smooth systems, which include the findings of a narrow band of chaos to the grazing condition and the abrupt onset to chaos caused by a dangerous bifurcation.The experimentally observed bifurcations are explained theoretically using mapping solutions between locally smooth subspaces. In order to understand the observed bifurcation scenarios, a global analysis has been undertaken to investigate the influence of stable and unstable orbits which are born in distant bifurcations but become important at the near-grazing conditions. A good degree of correspondence between the experiment and theory fully justifies the adopted modelling approach.Specially,similar phenomena were observed for a rotor system with bearing clearances, which was analysed numerically and experimentally.To gain further insight into the system dynamics a path following method has been developed to unveil complex bifurcation structures often featuring dangerous co-existing attractors.
报告人简介:
Marian Wiercigroch教授现为国际著名的应用动力学研究中心的创立者和负责人、英国阿伯丁大学六世纪主席、国际合作负责人;爱丁堡皇家学会院士(2009)、机械工程师学会会士(2009)、波兰Lodz工业大学荣誉博士(2013)、富布莱特奖获得者(1994)。Wiercigroch教授是理论和实验非线性动力学领域享誉世界的科学家,其专注于油气工程、故障诊断和振动控制、水声学、可再生能源、转子动力学、非线性振动等领域科学问题的研究;已经发表350余篇期刊和会议论文,现为国际著名杂志《International Journal of Mechanical Sciences》的主编,并担任《Acta Mechanica Sinica》、《International Journal of Non-linear Mechanics》等多个国际学术期刊的编委,多次担任国际会议主席或组织者。
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