Hello all,
Can someone help me with the modal analysis using the lumped mass approach with mass and rotational inertia applied to a node that is connected to another part using a rigid tie?
Do you have any specific doubts about that ? You have to use the keyword editor to define point mass (*MASS keyword). It’s typically applied to the reference node of a rigid body constraint. The required input file syntax is described in CalculiX User’s Manual.
I am clear with defining mass, but i am not sure regarding inertia definition at same node
Unlike Abaqus, CalculiX doesn’t have rotary inertia elements, you can only use the mass ones.
Is there any way to predict torsional frequency with mass in frequency analysis
In case of rotational modes need to be consider, someone can stick with distributed mass in the CalculiX model instead of lumped. Make it sparse (e.g lumped only at beam column intersection in 3D portal frames) with an eccentricity to centre of mass seems also possible.
P.s a specific constraint function names Rigid Diaphragm is not available in CalculiX and Abaqus, it will significantly different with Rigid Body.