Frequency & Eigenvalue from dynamic eqn

[rk81]

Hi, i am trying to find the natural period of a vertical cantilever beam which is fixed at bottom and free at other end., i worked out the global M & K matrices and i have the eqn in the form [M]-w^2[K] = 0, the M & K are not diagonal matrices, but square symetric matrices of rank 6. i understand that w2 is the cyclic frequency, how do i solve this characteristic polynomial the matrix way.. thanks in advance,

 

[Dr.D]

You need a numerical eigensolution, such as is available in many numerical analysis packages (NAG, EisPack, etc.). I think MatLab probably has one as well, and there are many other sources as well.

 

[rk81]

thanks, i think i found the answer.. i need to make the matrix to diagonal form, and then the soln is simple.