A spring dashpot model for dynamic analysis of beam-like structure with clearance

In a large number of engineering structures, clearance always exists due to assemblage, manufacturing errors and wear. The presence of clearance may lead to intermittent contact or impacts. For such structures accurate assessment of dynamic response is necessary for design against excessive vibration and wear as well as noise. In this paper we are interested in the study of the dynamic behavior of a cantilever beam structure with clearance. Simulation and experimental tests were carried out for this goal. For simulation tests, clearance was equivalent to a spring-dashpot model with consideration of vertical and angular motions, the impact of beam and boundary face was also taken into consideration. A cantilever beam set-up was designed and built for experimental validations. The presented results showed that the system responses were greatly influenced in the presence of clearance. The peak value of beam’s time-domain signal is larger with the clearance enlargement. The high-order harmonics are more possible to exist in frequency-domain signals when clearance size increases. The effects of clearance should not be ignored when analyzing the dynamic performance and vibration characteristic of engineering structures.