Problems for Chapter 5

 

Analytical Techniques and Solutions for Linear Elastic Solids

 

 

 

5.10.    Solutions to Dynamic Problems

 

 

5.10.1.    Use the Rayleigh-Ritz method to obtain the natural frequency of vibration of the spring-mass system shown (the displacement associated with the vibration mode is trivial)

 

 

 

5.10.2.    Use the Rayleigh-Ritz method to estimate the fundamental frequency of the spring-mass system shown.  You should be able to obtain an exact result, by describing the mode shape in terms of a single parameter, and minimizing the frequency appropriately.

 

 

 

5.10.3.    Reconsider problem 5.10.2.  Try to find the second frequency of vibration for the system by selecting another approximation to the mode shape, which is (by construction) orthogonal to the first.

 

 

 

 

 

5.10.4.    Use the Rayleigh-Ritz method to estimate the fundamental frequency of the clamped-pinned beam illustrated in the figure. Assume that the beam has Young’s modulus  and mass density , and its cross-section has area A and moment of area .

 

 

 

 

 

5.10.5.    Use the Rayleigh-Ritz method to estimate the fundamental frequency of the pinned-pinned beam illustrated in the figure. Assume that the beam has Young’s modulus  and mass density , and its cross-section has area A and moment of area .

 

 

 

 

 

5.10.6.    A beam with length L Young’s modulus  and mass density , and its cross-section has area A and moment of area  is bonded to an elastic foundation, which exerts a restoring force per unit length  on the beam.  The beam is pinned at both ends. Use the Rayleigh-Ritz method to estimate the natural frequency of vibration of the beam. 

 

 

 

 

 

(c) A.F. Bower, 2008
This site is made freely available for educational purposes.
You may extract parts of the text
for non-commercial purposes provided that the source is cited.
Please respect the authors copyright.