Publications
A post processing algorithm to add damping to undamped model responses
In linear finite element models, proportional damping is often used. In general this does not produce results that match experimental measurements. Modal damping is a much better option, but sometimes is incovenient. It may be cumbersome to calculate all the modes and keep track of what damping should be applied to each mode. If an explicit code is used, the modes are not available directly, so modal damping cannot be applied. A new approximate algorithm is demonstrated which allows the damping to be applied to undamped model response time histories. The damping is applied in user chosen frequency bands to as high a frequency as desired. Different damping may be applied to each response location. The method is demonstrated to be virtually equivalent to applying modal damping in bands. Examples are shown for a two degree of freedom spring-mass-damper system and a finite element model with 100 modes in the bandwidth.