Function
- Using the value entered in Model > Properties > Group Damping, damping ratios for individual modes are produced in a graph.
Call
From the Main Menu select [Results] tab > [Type : Analysis Result] > [Dynamic] group > [Modal Damping Ratio..]
Input
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.
The Calc. Alpha Beta Button : Based on the selected modes, a mass proportional damping coefficient (Alpha) and a stiffness proportional damping coefficient (Beta) are calculated.
The Graph Range Button : 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
The Calculate & Plot Button : Using the calculated Alpha and Beta, the Rayleigh Damping graph is produced.