Topic: To be announced

Xuedong Chen

Huazhong University of Science and Technology

Abstract:   To be announced

Biography:   Professor Xuedong Chen, Member of the Chinese Academy of Engineering, is a distinguished mechanical engineering expert and academic leader at Huazhong University of Science and Technology (HUST). Currently, Prof. Chen serves as the deputy director of State Key Laboratory of Digital Manufacturing Equipment and Technology at HUST. He has dedicated his career to mechanical dynamics and control, addressing critical challenges in China’s high-end equipment development. His pioneering research focuses on precision vibration reduction, strength enhancement for heavy-load equipment, and ultra-precision motion control. Prof. Chen has been awarded several prizes, including two Second Class Prizes of the State Technological Invention Award, one Second Class Prize of the State Scientific and Technological Progress Award, and five First Class Prizes of the provincial and ministerial awards. Prof. Chen was appointed as Changjiang Scholar distinguished Professor by the Ministry of Education in 2008, and selected into the “National Hundred, Thousand, and Ten Thousand Talents Project” in 2013. His academic contributions include 103 SCI-indexed papers, 2 monographs, 134 authorized domestic and international patents, 30 software copyrights, and 4 technical standards.

Engineering Intentional Nonlinearity in Dynamics and Acoustics

Alexander F. Vakakis     

University of Illinois at Urbana – Champaign

Abstract:   Nonlinearity is a mechanism to scatter energy across temporal and/or spatial scales (e.g., frequencies / wavenumbers, or system modes). A distinctive and rather unique feature of nonlinear effects is their high tunability with energy, the initial state of a system or other system parameters, which enables new options with unprecedented passive multi-functionality in engineering design. This contrasts to linear systems where no such tunability exists due to incapacity for multi-frequency harmonic generation. Engineering intentional nonlinearity, therefore, has become an interesting emerging trend, with great promise for the future. In this talk we present our vision regarding this exciting new approach, by discussing some basic elements of nonlinear energy management in practical vibration engineering, including capacity for targeted energy transfer (TET) to local nonlinear energy sinks; intermodal TET in multi-modal systems, or interband TET in phononic systems; rapid and effective energy redirection in preferential directions or preferred frequency/wavenumber bands; designing and tuning the bandwidth of nonlinear oscillators through multi-harmonic energy scattering; enhanced vibration, shock and blast mitigation; managing fluid-structure interactions of in-flow bodies with internal nonlinear elements; and some additional interesting new effects. Combined with powerful modern computational tools, such as machine learning and multi-objective optimization, advanced system identification and reduced-order modeling, and rigorous experimental validation, this approach may p[rove to be transformative in engineering design of dynamic and acoustic systems.

Biography:   Alexander F. Vakakis received his Ph.D. from Caltech (1990 – T.K. Caughey advisor),  M.Sc. from Imperial College, London, UK (1985 – D.J. Ewins advisor), and Diploma in Mechanical Engineering from the University of Patras, Greece (1984 – S.A. Paipetis advisor). Currently he is the Donald Biggar Willett Professor of the College of Engineering at the University of Illinois at Urbana – Champaign (UIUC) where co-directs the Linear and Nonlinear Dynamics and Vibrations Laboratory (http://lndvl.mechse.illinois.edu/); moreover, he is co-affiliate faculty at the University of Stuttgart, Germany. Among other awards, he is the recipient of the Tau Beta Pi Daniel C. Drucker Eminent Faculty Award from the UIUC College of Engineering (2023), the best paper award of the journal Nonlinear Dynamics (2023), an Alexander von Humboldt Research Award (2019), the Edmond J. Safra Visiting Professorship from Technion (2019), and the ASME Thomas K. Caughey Award in nonlinear dynamics (2014). He has published over 370 archival journal publications, holds four patents, and has authored/edited 6 technical texts and monographs. Many of his PhD students and postdoctoral fellows are currently faculty members in US and International Universities and National Laboratories, or researchers in R&D Centres. His research interests include nonlinear dynamics, vibrations and acoustics, passive energy management and targeted energy transfer across scales, phononics and acoustic metamaterials, system identification and reduced order modelling, non-smooth dynamics and vibration energy harvesting.

Topic: To be announced 

Grzegorz Litak    

Lublin University of Technology

Abstract:   To be announced

Biography: Grzegorz Litak is a professor and head of the Department of Automation at Lublin University of Technology. His research interests include bifurcation theory, chaotic dynamics, and nonlinear time series analysis. Recently, he has also been involved in research on mechanical energy harvesting, with a particular focus on frequency broadband effects. From 2016 to 2018, he served as a professor at the Akademia Górniczo-Hutnicza University of Science and Technology. He is an expert in nonlinear and complex phenomena and has published over 300 papers, including approximately 250 in international journals. He actively collaborates with researchers from various countries around the world. Currently, he is a member of the Polish Physical Society, the European Physical Society, the Polish Society of Theoretical and Applied Mechanics, and Euromech. He has been an organizer and invited speaker at numerous international conferences and has served as the contractor and manager of many national and international projects.

Locally Resonant Nonlinear Metamaterials

Walter Lacarbonara      

Sapienza University of Rome

Abstract:   This talk explores 2D and 3D metamaterials featuring a periodic arrangement of highly tunable infinite-dimensional resonators, such as cantilevers with tip masses and spider-web membranes. These locally resonant metamaterials exhibit distinctive dispersion characteristics, including the emergence of single and multiple band gaps. The sensitivity of these band gaps to key design parameters is discussed. By harnessing tailored geometric and material nonlinearities, the resonators significantly enhance band gap behavior. Using a perturbation approach, nonlinear wave frequencies and waveforms both near and away from internal resonances are used to show the remarkable nonlinear tunability—an essential attribute for advanced applications. To validate our theoretical predictions, we experimentally test various 3D-printed metamaterial samples using 3D laser scanning vibrometry. The results reveal fascinating wave propagation properties and confirm the enhanced performance driven by nonlinear effects.

Biography:   Walter Lacarbonara is a Professor of Nonlinear Dynamics at Sapienza University and Director of the Sapienza Center for Dynamics. During his graduate education he was awarded a MS in Structural Engineering (Sapienza University) and a MS in Engineering Mechanics (Virginia Tech, USA), and a PhD in Structural Engineering (Sapienza/Virginia Tech). His research interests cover nonlinear structural dynamics; metamaterials and nanostructured composites; asymptotic techniques; nonlinear control of vibrations; experimental nonlinear dynamics; dynamic stability of structures. He is Editor- in-Chief of Nonlinear Dynamics, former Associate Editor for ASME Journal of Applied Mechanics, Journal of Vibration and Acoustics, Journal of Sound and Vibration. He served as Chair of the ASME Technical Committee on Multibody System and Nonlinear Dynamics, General co-Chair and technical program co-Chair of the ASME 2015 (Boston, USA) and 2013 (Portland, USA) IDETC Conferences. He has organized over 10 international symposia/conference sessions and, very recently, the 1st, 2nd, 3rd, and 4th International Nonlinear Dynamics Conferences (NODYCON, www.nodycon.org/2019, www.nodycon.org/2021, www.nodycon.org/2023, www.nodycon.org).

His research is supported by national and international sources (EOARD/AFOSR, NSF, European Commission, Italian Ministry of Science and Education). He has published over 250 papers and conference proceedings, 5 international patents (EU/USA/China), 26 book chapters, 9 co-edited Springer books and a single-authored book  (Nonlinear Structural Mechanics, Springer, NY, https://link.springer.com/book/10.1007/978-1-4419-1276-3) for which he received the 2013 Texty Award nomination by Springer US.

Performance, Accuracy, and Stability of Manufacturing Processes and Machines

Kornel F. Ehmann

Northwestern University

Abstract:  The outcome of any manufacturing operation critically hinges on the ability to control the primary physical process responses, e.g., temperatures, forces, vibrations, etc., which influence the part’s attributes, such as its accuracy, tolerances, surface topography, residual stresses, etc., while, at the same time, assuring dynamic process and machine stability. Several examples from removal, formative, and additive processes will be presented to demonstrate the varying nature of the pragmatic manufacturing and manufacturing machine problems dictated by the underlying dominant physical mechanisms influencing their responses, necessitating different control and compensation solution approaches. Specifically, the following cases will be addressed: (a) the inherent non-linear nature of micro-cutting operations and its implications on process outcomes, (b) forming force and springback control in double-sided incremental sheet forming to maintain part accuracy, (c) dynamic instability, i.e., rolling chatter, in sheet rolling to assure sheet quality and productivity, (d) volumetric error compensation of a 3-DOF translational parallel manipulator to compensate for inherent machine kinematic and geometric errors, and (e) melt pool control in directed energy deposition (DED) processes to meet desired part specifications.

Biography:  Kornel F. Ehmann is a distinguished professor of the Department of Mechanical Engineering at Northwestern University, USA. He received BSc and MSc degrees in 1970 and 1974 from the University of Belgrade, and a PhD from the University of Wisconsin-Madison in 1979. He has served as Editor-in-Chief of Manufacturing Letters and Technical Editor of the Journal of Manufacturing Science and Engineering. He has published over 450 articles and mentored over 60 Ph.D. students. He was awarded the SME Gold Medal, ASME Blackall Machine Tool and Gage Award, ASME Milton C. Shaw Manufacturing Research Medal, SME Frederick W. Taylor Research Medal, and the ASME K. Ehmann Manufacturing Medal. He is a Fellow of ASME, SME and ISNM.