Reduction in forced vibration of a pipe by means of a controllable ring dynamic vibration absorber

A controllable dynamic vibration absorber is proposed to control the forced vibration of a piping system connected to rotating machinery such as a compressor,based on the principles of a dynamic vibration absorber.Separate multiple discrete distributed ring dynamic vibration absorbers with the same natural frequency for a piping system were designed,and dynamic vibration absorber-pipeline finite element models for simulation were established. Corresponding experiments were carried out to verify the model. In order to overcome the two resonance peaks caused by a dynamic vibration absorber,a controllable ring dynamic vibration absorber was designed to suppress the forced vibration of the pipe. Both the simulation and experimental results show that the dynamic vibration absorber can not only adapt to the spatial conditions of the large amplitude vibrations appearing in a large piping system,but better vibration reductions can be achieved with wider absorbing frequency bands,up to 20 Hz bandwidth. More stable effects are obtained by using separable multiple discrete distributed controllable ring dynamic vibration absorbers with the same natural frequency,which solves the detuning problem of a single and a multiple dynamic vibration absorber and allows the pipeline steady-state forced vibration amplitude to be controlled effectively.