Graduate Cart pendulum problem when the pendulum is a beam with torsional stiffness

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SUMMARY

The discussion focuses on the cart pendulum problem, specifically addressing the impact of torsional stiffness at the base of the column. The participant suggests that the torsional stiffness can be approximated using dummy loads in a structural model. They highlight the observation of resonance between vibrations characterized by stiffness values k_b and k_c, particularly in relation to earthquake simulations. The participant also mentions experimenting with state representation through first-order differential equations, noting expected behaviors when varying the k_b stiffness at different time intervals.

PREREQUISITES
  • Torsional stiffness concepts in structural dynamics
  • Understanding of resonance in mechanical systems
  • Familiarity with state representation and differential equations
  • Experience with structural modeling techniques
NEXT STEPS
  • Research methods for approximating torsional stiffness in structural models
  • Explore resonance phenomena in mechanical systems, particularly in relation to earthquakes
  • Learn about state-space representation in control systems
  • Investigate the effects of varying stiffness parameters on system behavior
USEFUL FOR

Structural engineers, mechanical engineers, and researchers involved in dynamic systems analysis and earthquake engineering will benefit from this discussion.

Mishal0488
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The cart pendulum problem however the pendulum is a beam with a torsional stiffness
Hi Guys

Please refer to my attached derivation, do you think it is acceptable?
There is a torsional spring at the base of the column. in reality the column is going to be a complex structure however the torsional stiffness can be approximated using dummy loads on the structural model.
 

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I have not followed your calculations fully. As a hint for verifivation, have you observed resonance between vibrations with k_b and k_c, in resemblance of earthquakes ?
 
I have got sinusoidal results, if k_b and k_c are appropriate resonance does exist. When representing the system in state representation (1st order differential equations) I have played around with removing the k_b stiffness at different time steps and I do get behavior that I expect.
 
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