This lecture deals with self-excited vibration phenomena. The lecture aim and the lecture plan are as follows.
The course aims to teach basic concepts and recent developments related to mechanical vibrations, structural dynamics, acoustics, and vibration control.
By the end of this course, students will be able to:
(1) Understand the difference between self-excited vibration and forced vibration
(2) Understand the generation mechanism of self-excited vibration
(3) Explain the countermeasures against self-excited vibrations in consideration of their generation mechanism
Self-excited vibration, Stability criterion, Unstable vibration, Negative damping, Friction induced vibration, Parametric excitation, Dry friction, Surging, Galloping, Time delay, Chatter, Coulomb friction, Flutter
|✔ Specialist skills||Intercultural skills||Communication skills||Critical thinking skills||✔ Practical and/or problem-solving skills|
The course is taught in lecture style. Handouts are given in class when necessary. Exercise problems will be assigned.
|Course schedule||Required learning|
|Class 1||Introduction||Find some examples of self-excited vibration|
|Class 2||Stability analysis||Understand the stability analysis|
|Class 3||Unstable vibration caused by negative damping||Understand the unstable vibration caused by negative damping|
|Class 4||Unstable vibration caused by time delay||Understand the unstable vibration caused by time delay|
|Class 5||Unstable vibration caused by asymmetries of stiffness matrix 1||Understand the friction vibration caused by the asymmetries of stiffness matrix|
|Class 6||Unstable vibration caused by asymmetries of stiffness matrix 2||Understand flutter|
|Class 7||Countermeasure against self-excited vibration and review of the whole course||Understand the countermeasures against self-excited vibrations and review of the whole course|
To enhance effective learning, students are encouraged to spend approximately 100 minutes preparing for class and another 100 minutes reviewing class content afterwards (including assignments) for each class.
They should do so by referring to textbooks and other course material.
J. P. Den Hartog著, “Mechanical vibrations”, Dover Publications, ISBN-13: 978-0486647852
Singiresu S. Rao著, “Mechanical Vibrations”, Prentice Hall; 5th Revised, ISBN-13: 978-9810687120
The Japan Society of Mechanical Engineers, “Mechanical Engineering Handbook Fundamentals (α2) mechanical dynamics”, The Japan Society of Mechanical Engineers, ISBN-13: 978-4888981163
Learning achievement is evaluated by exercise problems(30%) and a final exam(70%). However, if a face-to-face final examination cannot be held due to the spread of COVID-19 infection or other reasons, it will be evaluated by reports assigned for classes.
Students must have successfully completed both Mechanical vibrations (MEC.D201) and Vibration Analysis (MEC.D311) or have equivalent knowledge.