Hi, I´ve tried to calculate the vibration modes of beam in the space, without gravity or any other force. The forumle of the beam is this one: Cos(λL)*Cosh(λL)=1 from which I´ve calculate the roots and the resonance. I´ve found a programme for Matlab that calculates the vibrations modes if you enter the mass and stiffness matrix but it´s here where I´m facing some troubles. I don´t know how to build the stiffnes matrix of this beam. For the mass matrix I´m going to use this methog. Do you know if it´s going to work properly? I´ve all the dimensions, density and the young´s modulus of the material (steel). Thanks in advance.