Skip to main content
J
Jslim_1041156-Contributor
6-Contributor
November 27, 2023
Solved

solving numerically the frequency and mode of the problem

  • November 27, 2023
  • 1 reply
  • 3852 views

Dear forum

 

In Euler-bernoulli theory, I am solving numerically the frequency and mode of the problem in which both ends are supported by springs in the vertical sagging of beams. Through this, the mode of the continuous beam is intended to be represented as a picture.

In the paper for reference, the angular frequency was calculated using MATLAB's system variable 'K' and "Inline function".

 

MATLAB from reference.

Jslim_104115_0-1701070038879.png

reference) Impacts of various boundayr conditions on beam vibrations. Ye Tao, 2015

My code is as attached.  I need help on how to implement this with MATCAD. When trying to implement using MATHCAD in the same way, it is difficult to solve the equation using a function and find each solution as the number of frequencies increases. Inquire about how to apply the function to this.

    Best answer by Fred_Kohlhepp

    A good reason to state the version level when you post a file--later versions can read earlier but early can't read later.  Attached pdf version, mods aren't challenging.  Note Werner's improvements!

    1 reply

    F
    Fred_Kohlhepp23-Emerald I
    23-Emerald I
    November 27, 2023

    You've run afoul of Prime's dreaded labels problem, some of your K's show as bold blue--Prime thinks they're a unit rather than a variable.

     

    You can plot the determinant of a matrix for each value of K, then solve for the roots of that equation.  Example in P9 attached (without roots.)

    W
    Werner_E25-Diamond I
    25-Diamond I
    November 27, 2023

    Some observations:

    Werner_E_1-1701101386941.png

    Werner_E_2-1701101547962.png

    Werner_E_3-1701101618505.png

    etc.

    Werner_E_5-1701101907685.png

     

     

     

     

     

     

      J
      Jslim_1041156-ContributorAuthor
      6-Contributor
      November 28, 2023

      Thank you very much for your response. I tried to apply the method of giving a specific range and solving the solution like your method, but I still think we need to organize more to apply the method of doing the harm and solving (understood like the false position root finding method) like the attachment.It is still difficult to find the determinant, and to find the value for each mode.

      Terms & ConditionsAccessibility statement