The influence of friction models on passive damping and dynamic response of a flexible beam structure

摘要

The influence of different friction models on the damping and dynamic response of a flexible structure is investigated. Five different models of dry (unlubricated) friction are studied: four of the models employ a friction coefficient that varies with relative slip velocity, while the fifth model uses a friction coefficient that varies with normal load across the friction interface. The various friction laws are incorporated into a structural system consisting of a flexible, extensible beam restrained by a frictionless pin connection at one end, and a frictional interface at the other. The logarithmic decrement is used in conjunction with the system's free response to compare the passive damping level supplied by each friction model. The damping results are compared with those obtianed using a traditional constant-mu friction model. The time history of interfacial sliding velocity is also examined. It is found that, while the longitudinal dynamics are strongly effected by the nature of the friction law, the effect on transverse dynamics are relatively slight. Thus the constant-mu friction model yields surprisingly accurate results for this particular system.