Parametric instability in linear and nonlinear systems: Some new results
Dr Peter Hagedorn
TU Darmstadt, Germany and Dept. of Mech. Eng. University of Canterbury
Time & Place
Thu, 20 Feb 2020 11:00:00 NZDT in E12 (Lecture Theatre), Engineering CORE
In mechanical engineering systems, self-excited and parametrically excited vibrations are in general unwanted and sometimes dangerous. There are many systems exhibiting such vibrations which up to this day cannot be completely avoided, such as brake squeal, the galloping vibrations of overhead transmission lines, the ground resonance in helicopters and others. The flutter of an aircraft wing is of the same type, but fortunately can be avoided by appropriate design methods. Most of these systems have in common that in the linearized equations of motion the self-excitation terms are given by non-conservative, circulatory forces and/or parametric excitation. The presentation will deal with some practical engineering examples and discuss some recent results obtained for parametrically excited systems.
Dr. Hagedorn graduated in mechanical engineering and earned a doctoral degree at EPUSP (Brazil) and completed his ‘habilitation’ (similar to Dr. Sc.) at TU Karlsruhe, Germany. Among other universities he served as visiting professor at Rio de Janeiro (Brazil), Berkeley, Paris, Irbid (Jordan) and Christchurch (New Zealand), where he also holds an Adjunct Professorship at UC, and spent two years as a research fellow at Stanford University. He is a full professor of mechanics since 1974 at TU Darmstadt, Germany, since 2019 as an emeritus. He is author of about 300 papers and several books on dynamics, vibrations and analytical mechanics. He presently heads the Dynamics and Vibrations Group at TU Darmstadt.