Mechanical Vibrations

György Szeidl was born in Esztergom (Hungary) on September 8, 1942. After graduating from the Pelbárt Temesvári Catholic High School in 1960 I worked for the Machine Tools Factory of Esztergom till 1962 when I was admitted to the Mechanical Engineering Faculty of the Miskolc University. I earned a master's degree with honours in mechanical engineering in 1967. In the very same year I began to work for a research group at the Department of Mechanics (which was financed by the Hungarian Academy of Sciences). I had the following positions there: (a) assistant (1976-1969), (b) research fellow (1969-1985) (c) senior research fellow (1985-1992). In 1992 I left the research group and was employed full time by the Department of Mechanics till 2013 when I retired. Since then I have been working part time for the very same Department (renamed to Institute of Applied Mechanics in 2014). Positions held: (a) associate professor (1992-1999), (b) full professor (1999-2013) -- head of department between (2003-2007), (c) professor emeritus since 2013. Scientific degrees: (a) PhD from the University of Miskolc in 1976, (b) PhD from the Hungarian Academy of Sciences in 1985, (c) Dr. habil from the University of Miskolc in 1998, (d) DSc (Doctor of Science) from the Hungarian Academy of Sciences in 2006. My research interests are as follows: (a) dual variational principles in micropolar theory of elasticity (c) boundary element method in a dual formulation (d) continuum mechanics of solid bodies (e) stability and vibratory problems of heterogeneous curved beams (f) eigenvalue problems of ordinary (differential equations)[differential equation systems]. Same data for my publication activity: (a) one book in Hungarian with a co-author (b) chapters in two English text books (c) thirty-seven research papers published in foreign languages (mainly in English and partly in Russian) in various journals, (d) eleven research papers in Hungarian (e) twenty-eight conference papers in English. I have been the scientific supervisor of 7 PhD theses. Two memberships might be mentioned: Editorial Board: Journal of Computational and Applied Mechanics (Since 2001), Editorial Board, International Journal of Applied Mathematics and Mechanics (Since 2004). László Péter Kiss was born in 1987. He received his MSc honours degree in mechanical engineering from the University of Miskolc in 2012. He defended his PhD at the same Institution in 2016 with 'summa cum laude'. The thesis was titled 'Vibrations and Stability of Heterogeneous Curved Beams'. Currently, he is a Senior Lecturer at the Institute of Applied Mechanics. He has been teaching Dynamics since 2012 and Mechanical Vibrations to foreign students since 2015. His research interests and activities include applied mechanics, stability theory, vibration theory, functionally graded materials, finite element simulations and the problems of beams and arches. So far, he has (co-)authored more than 50 scientific publications, including several articles in internationally recognized journals. He has been a reviewer for numerous international journals. He was a member of the Organizing Committee of the 13 th Hungarian Conference on Theoretical and Applied Mechanics. He has participated in a number of national research tenders and industrial projects.

Introduction.- Impact.- Some vibration problems.- Introduction to multidegree of freedom systems.- Some problems of multidegree of freedom systems.- Some special problems of rotational motion.- Systems with infinite degrees of freedom.- Eigenvalue problems of ordinary differential equations.- Eigenvalue problems described by degeneratedsystems of ordinary differential equations.