Research On Periodic Active Constraint Layer Damping Treatment Of Pipeline System

The pipeline system is widely used in aviation fields,with the characteristics of limited space,long span and elastic support.In addition,the high-speed and high-pressure fluid in the pipeline will also generate strong pulsations.These factors will cause resonance of the pipeline system structure or large-scale forced vibration.The main failure modes caused by pipeline vibration include: tube burst,tube wear,loose joints,clamp failure,cracks,etc.,which pose a great threat to the safety and reliability of the aircraft.Therefore,vibration control of pipelines has always been an engineering problem to be solved.Aiming at the problem of wide-frequency vibration suppression of pipeline system,this paper proposes periodic active constrained layer vibration reduction technology.Based on the theory of periodic structure,the active constrained layer damping is introduced on the surface of the pipeline,and the periodic pipeline structure is formed through the periodic array distribution,which can realize the vibration control of low and high frequency bands at the same time.The main research contents are as follows:(1)Analyze the vibration characteristics and energy band structure of the pipeline system.According to the stress-strain distribution of the pipeline system,the periodic pipeline structure was designed and its vibration band gap was calculated.By analyzing the vibration mode corresponding to each curve in the band gap curve diagram,the bending vibration band gap of the periodic pipeline is extracted.(2)Analyze the parameters that affect the band gap of the periodic pipeline structure and get the influence law of each parameter on the band gap start and stop frequency.The elastic modulus of the viscoelastic damping layer and the density of the piezoelectric ring has a greater impact on the band-gap frequency of the periodic structure.The vibration transmission characteristic curve of the periodic pipeline with finite period repetition is calculated,and based on the influence law of the parameter on the band gap,the influence law of the period repetition number on the transmission characteristic curve and the vibration reduction effect is analyzed,and the structure with the infinite period is verified.Correspondence of band gap.(3)Combining periodic structure theory and active control technology,a periodic active constrained layer damping pipeline with band gap characteristics is designed.The vibration damping performance was verified under different boundary conditions and excitation forms.(4)Vibration control by applying a control signal to the active constrained layer damping.The vibration control effect of pipeline system under different excitation forms and different control parameters is analyzed.The amplitude of the active control voltage,the excitation form and the excitation amplitude all have a greater influence on the control effect.