Damping, a property of the material and the structure, influences dynamic response. A certain type of damping is available for each type of load case. Within all load cases of a certain type, damping is applied consistently, though additional damping may be added to individual load cases.
- Modal damping is used for response-spectrum and modal time-history analyses. Material modal damping, also known as composite modal damping, is weighted according to element and modal stiffness. For each material, users specify a material modal damping ratio r, in which 0 < r < 1, which relates to the damping ratio of each mode.
- Viscous proportional damping is used for direct-integration time-history analysis. This property is proportional to mass and stiffness.
- Damping devices may also be modeled as a structural subsystem, as described in the Tuned-mass damper tutorial.
|Tuned-mass damper||An overview of the tuned-mass damper and guidelines for modeling the device.||SAP2000|