Learning Forum

[Rajveer7]

I am trying to extract Modal Transformation matrices (all eigen vectors) for a simple cantilever beam, fixed from one end & suspended at the other. Can anyone please share the code & how can I view it after extracting them. Thanks for helping in advance !

[peteroznewman]

nAre you only interested in exporting data?nHave you already created the Deformation plots for all the modes in Mechanical to look at the shape and the frequency?n

[Rajveer7]

nYes I have created deformation plots (attached below), I am interested in extracting Modal transformation matrices as I need it in some form which can be later fed to MATLAB in some form for further calculations. So anyways, How can I extract all the required data ?.n

[Md_Salem]

Hello,

I tried to use the APDL command to extract the mass and stiffness matrices, then solve them linearly as an Eigen value problem in MATLAB to get the modal matrix (combination of Eigen vectors), but there was a serious problem: the corresponding Eigen values (which are supposed to be natrural frequencies) don't match totally with those given by the ANSYS modal analysis. I think this problem needs some intention. It is a really serious one.

Regards

[Emmal Walt]

Modal transformation matrices, also known as mode shape transformation matrices or eigenvector transformation matrices, are used in structural dynamics to transform a system's coordinates from the physical space to the modal space. They are typically derived through modal analysis, which involves solving the eigenvalue problem of the system's equations of motion. You can choose trap the cat!