This video presents the third class in mechanical vibration course. It contains energy and Lagrange method for writing the governing equations of SDOF systems. Also, it has some basics on the obtaining the stiffness of well known and simple structures like beams and bars. It finally presents the concept of equivalent stiffness with some solved examples.
![](https://i.ytimg.com/vi/hHjSavfDXN8/maxresdefault.jpg)