I have to find first 45 frequencies of a 3D beam numerically. I am using ansys right now. If I have to get these frequencies with pretty good accuracy, which method should I use? What are the things those need to be ensured? Can somebody help me in this context?
Thanks,
Dhanashri
Hi You can
Hi
You can use FEM to solve the problem. What you have to do is solve the Eigen value problem det(K-w^2M) = 0. What you have to do is mesh the beam you have with suitable elements. Get the stiffness matrix, get the mass matrix and solve the eigen value problem, where the eigen values will be squares of your natural frequencies. For theory you can refer any book on FEM. Actually we consider only first few natural frequencies. As you want around 45 in number your meshing part should be important one.
Just go through the following once, it may give some idea.
http://www.awuz.de/notizen/downloads/simulationen/schwingerkette/schwin…
Inspiration and genius--one and the same.
_______________________________________ ----------------------------------------------------------------------
Siva Srinivas Kolukula
Junior Research Fellow