Hello,

On a mechanical system that I could put in the classic form M*diff (x, t, 2) + K*x (t) = 0, I would like to calculate the angular frequencies.The methods that I know are:
- Calculate the solutions of the equation det (K-omega ^ 2 * M) = 0
- Or calculate the solutions of the equation det (M-1K-omega ^ 2 * I) = 0
- Or directly determine the eigenvalues ​​of M-1K using functions already created in Maple for example.

Hello,

I use the module DynamicSystem to transform a state system in transfer functions. Next, i can plot Bode diagram with this module.

However, i have a little problem. I don't manage to extract only one transfer function from a dynamic system when i have several transfer functions (see example below)

I'd like to plot the first transfer function alone in fact. How can i extract y1(s) ?

Hello, 

I didn't manage to evaluate the following sum of 2 matrix M*p²+K. 
The 2 matrix can be evaluated separately.
But, strangely, whan i try to evaluate the sum, i can get the numerical values. 

Let's see :

[img]http://www.gilawhost.com/images/s7ur3of2.gif[/img]

 

Hello,

How can i simplify the following expression which should be a function of omega

Thank you for your help

Hello, 

I'd like to identify terms before the differential terms (theta(t), diff(theta(t),t) ...)

The following code with coeff function works for  diff(theta(t), t, t)) but not for diff(theta(t), t)

Here the code :

eq1pp := R(t) = -(-sin(theta[0]+phi)*Isup-sin(theta[0]+phi)*L[fixe]^2*M[fixe]-sin(theta[0]+phi)*L[r]^2*M[r]-sin(theta[0]+phi)*L[sup]^2*M[sup]+cos(theta[0]+phi)*a*sin(phi)*L[fixe]*M[fixe]+cos(theta[0...