A modal analysis aims to study the dynamic behavior of a model. The natural frequencies are determined and the modal masses as well as the participation factors are determined. This task is detailed in Natke Refer [1 ], Tedesco Refer [2 ] and Stelzmann Refer [3 ] described.
The Modal Analysis add-on determines the lowest eigenvalues of the structure. You can specify how many eigenvalues are to be determined. You can import the relevant masses from load cases or load combinations (with the option of considering the total load or only the Z component) or you can define them manually as additional masses at nodes, lines, members or surfaces. In addition, you can influence the stiffness matrix by taking normal forces or changes in stiffness of a load case or load combination into account.
The currently available design standards and a summary of the functional scope can be found in the product description Modal analysis for RFEM 6/RSTAB 9.
