报告题目1： Micro-perforated Boundary Modulated Slow Waves for Sound Absorption in a Sonic Black Hole Structure

报告时间：2024年4月12日（周五）上午9：00

报告人：成利 教授（香港理工大学）

报告地点：明故宫校区18号楼529会议室

主办单位：航空航天结构力学及控制全国重点实验室、航空学院、校科协

报告内容简介：

Wave manipulation through retarding structures is an emerging and enabling concept which is the cornerstone of numerous applications. The phenomenon of the Sonic Black Hole (SBH) can be produced inside a retarding structure to generate unconventional slow waves alongside significant energy focalization. Whilst alluding to promising solutions for conceiving acoustic wave manipulation and control devices, the phenomenon is less exploited as compared with its vibrational counterpart in the open literature, mainly due to some unsolved bottlenecking problems which hamper its realization as well as its subsequent applications. This talk addresses some of these problems. In particular, perforated acoustic boundaries are incorporated into a conventional SBH structure. Perforation parameters can be tactically tuned to balance the required surface admittance variation of the sonic retarding structures and the energy dissipation with the goal of maximizing the SBH effects through simplified structural design. Meanwhile, slow waves produced in the proposed SBH structures as well as efficient sound absorption are experimentally confirmed.

报告题目2： Nonlinear Guided Waves and Meta-material devices for Incipient materials/Structural Damage Monitoring

报告人：成利 教授（香港理工大学）

报告时间：2024年4月12日（周五）下午15：00

报告地点：明故宫校区18号楼529会议室

主办单位：航空航天结构力学及控制全国重点实验室、航空学院、校科协

报告内容简介：

Structural health monitoring (SHM) is an emerging technology aiming at the on-line diagnosis of damages inside structures during their operation. Successful implementation of SHM allows enhancing the safety and evaluating residual lifetime of structures in service, thus avoiding exorbitant maintenance costs. Among various SHM approaches, the one based on acousto-ultrasonic (AU) waves has become the research highlight due to its appealing advantages like larger monitoring range and high sensitivity to damage. This talk focuses on the detection of the incipient damage at its early stage of development using nonlinear guided waves, exemplified by Lamb waves. Issues relating to system design, frequency selection, as well as the mitigation of non-damage-related nonlinear sources in a detection system are discussed. Examples involving the monitoring of thermo-aged and fatigue-induced microstructural changes inside materials/structures are showcased. To top of the system design level, metamaterial devices are topologically designed as add-on wave manipulation devices to facilitate the SHM task in the context of nonlinear guided waves.

报告人简介：

成利，加拿大工程院院士，国际声学振动学会杰出会士，香港理工大学工程学院副院长，机械工程学讲座教授。成利教授在西安交通大学获得理学学士学位，在法国INSA de Lyon获得博士学位，1992年成为加拿大拉瓦尔大学讲师，2000年加入香港理工大学并晋升为正教授。成利教授在声振利用与控制、结构健康监测、智能结构等领域发表了大量论文。他目前担任《Journal of Sound and Vibration》、《Journal of the Acoustical Society of America》和《Structural Health Monitoring: An International Journal》期刊的副主编；ASA（美国声学学会）,中国声学学会, IMechE（英国机械工程师学会）, 香港工程师学会，香港声学学会等学会Fellow，I-INCE（国际噪声控制工程委员会）主席。