Differential equation for a vibration problem

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SUMMARY

The discussion focuses on solving a vibration problem using differential equations, specifically for a system with given acceleration data over time. The rigidity constant is 12,600,000 N/m and the damping constant is 6,500 N/m, with two of each in the system. The user successfully derived a third-degree polynomial equation and generated a corresponding differential equation. They seek assistance in implementing their findings in MATLAB or GeoGebra to extract coefficients and generate graphs.

PREREQUISITES
  • Understanding of differential equations and their applications in vibration analysis.
  • Familiarity with MATLAB or Octave, particularly the polyfit() function for polynomial fitting.
  • Knowledge of oscillation theory and damping in mechanical systems.
  • Basic skills in data visualization using software like MATLAB or GeoGebra.
NEXT STEPS
  • Research how to implement polynomial fitting in MATLAB using the polyfit() function.
  • Learn about the graphical capabilities of MATLAB for plotting functions over a specified range.
  • Explore the use of GeoGebra for visualizing differential equations and their solutions.
  • Study the principles of oscillation and damping to better understand the physical implications of the derived equations.
USEFUL FOR

Students and professionals in engineering, particularly those focused on mechanical systems and vibrations, as well as anyone looking to apply MATLAB or GeoGebra for mathematical modeling and visualization.

Reno Nza
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Homework Statement


The data given was the acceleration of the component over time, as below:
time | Acceleration (m/s²)
0 | 0
0,2 |3,61
0,4 |4,5
0,6 |5,4
0,8 |7,508
1 |12

-
The Rigidity constat is 12600000 [N/m] (for the spring)
The damping constant is 6500 [N/m] (for the damp)

The system has 2 of each.

Homework Equations


  1. I was required to construct the 3rd degree equation
  2. Generate the differential equation
  3. Determine the oscilation
  4. Solve the equation knowing that y(0)=0 and y'(0)=0 (So i get Constant1 and Constant2)
  5. Generate graphics for y(t) from 0 < t < 3s

The Attempt at a Solution


For nº 1 i got the following:
f(t) = 3600 * (33,697*x^3 - 46,4018*x^2 + 24,693*x + 0,0615)

For nº 2:
Knoginw that, C=6500 * 2 = 13000 and K=12600000 *2 = 25200000

So,
3600*y''+13000*y'+25200000*y= 121309,2*x^3- 167043,6*x^2 + 88834,3*x + 221,4

for the particular solution i used:
A*x^3 + B*x^2 + C*x + D

got the info of A,B,C and D and replaced.

Got the following:
y(t) = e^-1,8*t * [C1*cos(83,647*t)+C2*sen(83,647*t)]+ 4,81*(10^-3) * t^3 - 6,64*(10^-3) * t^2 + 3,523*(10^-3) * t +1,57*10^-5

And the problem goes on...

What i need \/
The point is, I'd like to port all this info to Matlab or Geogebra or whatever software you recommend, but i have no idea on how to, would be anyone able to help ?

I'd like to get the A,B,C and D, plus C1 and C2 and them generate the graphs, all on the software, using the data given.
 
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