报告承办单位: 数学与统计学院

报告内容: Dynamics of Time-Delayed Nonlinear Systems

报告人姓名:季进臣

报告人所在单位: 澳大利亚悉尼科技大学

报告人职称/职务及学术头衔: 副教授,博导

报告时间: 2019年1月18日 周五上午10:30

报告地点: 理科楼A419

报告人简介: 季进臣现为悉尼科技大学机械与机电工程学院副教授。他是国际公认的非线性动力学、分岔控制、振动和非线性工程系统控制领域的专家。在国际顶级SCI期刊发表论文85余篇。他参与了由政府各资助机构资助的各种研究项目。他的研究吸引了超过310万澳元的外部资金。

季进臣是《International Journal of Bifurcation and Chaos》等两份国际期刊的副主编。此外，他亦是澳洲、香港及欧洲科研项目申请的评审人。他曾担任国际会议主席，并在许多重要的国际会议上发表了他的研究成果。他是第十八届亚太振动大会(www.APVC2019.org)组委会主席，会议将于2019年11月在澳大利亚悉尼举行。

报告摘要：Time delay describes a situation that the present state depends on the state at previous times and can often be caused by the delayed reaction in sensors and actuators. Time delays have been found to exist in a number of engineering systems, for examples, magnetic bearing systems, maglev trains, controlled mechanical systems with delayed feedback, cold rolling mills, vehicle’s suspension system, rotating cutting and milling machines, etc. Existence of time delays in nonlinear mechanical systems can change the local stability of the trivial equilibrium of the corresponding autonomous system and induce complex dynamic behaviour in the non-autonomous systems.

This seminar will first discuss the practical examples of engineering systems involving time delay, and then the stability and dynamics of time-delayed nonlinear systems following Hopf bifurcations of the trivial equilibriums. The nonlinear systems include magnetic bearing systems, a van der Pol-Duffing oscillator with feedback control, and a quadratic nonlinear oscillator with feedback control. The secondary resonance response of the time-delayed nonlinear oscillator following two-to-one resonant Hopf bifurcations will also be discussed.