Modal Damping Ratio Based on Group Damping

Using the value entered in Model > Properties > Group Damping, damping ratios for individual modes are produced in a graph.

From the Main Menu select Results > Mode Shape > Modal Damping Ratio based on Group Damping

Calculation of Mass and Stiffness Coefficients

Mass and stiffness proportional damping matrix can be calculated. Depending on the selection of the user, Mass proportional damping, Stiffness proportional damping, or combined Mass & Stiffness proportional damping (so called Rayleigh Damping) can be applied.

Mode1, Mode 2: Select 2 modes for which damping ratios are input for calculating mass proportional and stiffness proportional damping coefficients.  

: Based on the selected modes, a mass proportional damping coefficient (Alpha) and a stiffness proportional damping coefficient (Beta) are calculated.

Specify the range of a graphic output by entering the maximum and minimum values in X and Y axes.

For details regarding the calculation method of Rayleigh Damping, refer to the Analysis Manual.

X Range Min: Minimum value along X-axis

X Range Max: Maximum value along X-axis

Y Range Min: Minimum value along Y-axis

X Range Max: Maximum value along Y-axis

Using the calculated Alpha and Beta, the Rayleigh Damping graph is produced.