Analysis Of Vibration Characteristics Of Pipeline System With Local Active Constrained Layer Damping

As an important energy transmission system in engineering,pipeline is widely used in aerospace,shipbuilding,petrochemical and other fields.Due to the complex layout and various types of pipeline system,it is easy to produce excessive vibration under the basic excitation of mechanical parts and fluid pulsation excitation.Especially when the pipeline is in the vibration environment for a long time,it is easy to produce faults such as collision between pipes,pipeline wear and pipe burst,which seriously affects the safe operation of equipment and personnel life safety.The existing pipeline control methods mainly focus on passive vibration reduction,which mainly realizes the vibration reduction of the pipeline by increasing the damping of the support,pasting damping materials on the surface of the pipe,optimizing the support layout,etc.There are some problems,such as poor low-frequency control,narrow control frequency range and so on.Active constrained layer damping（ACLD）technology is an active passive composite control structure.Piezoelectric materials are used to replace the traditional constraint layer.It has good control ability for high and low frequency vibration,and the control parameters can change adaptively with the change of environmental excitation.It has great application potential in the vibration control of complex electromechanical systems.Therefore,this paper puts forward the pipeline vibration reduction technology of locally laid active constraint layer damping structure.Using the combination of numerical calculation,simulation analysis and test,this paper compares and studies the pipeline vibration characteristics of locally laid active constraint layer damping structure,and verifies the vibration control effect of active constraint layer damping structure on different shapes of pipelines.The main research contents are as follows:Firstly,the mechanical properties of viscoelastic damping materials and piezoelectric materials are analyzed.Using the finite element principle,the finite element model of locally laid active constraint layer damping pipeline is established,and its dynamic equation is deduced.The validity of the model is verified by comparing the results of finite element software with those of references.The influence of structural parameters of active constrained layer damping on pipeline damping characteristics is further analyzed.Secondly,the dynamic modeling method of active constraint layer damping pipeline system considering fluid is proposed.PD algorithm is used to feedback control the active constraint layer damping pipeline,and the dynamic model of complex pipeline system with active constraint layer damping structure is deduced.Taking typical L-shaped and T-shaped pipelines as examples,the effects of parameters such as proportional / differential gain,excitation voltage and viscoelastic layer thickness on the dynamic response characteristics of active constraint layer damping pipeline are analyzed,and the influence laws of control parameters and structural parameters on the vibration control characteristics of pipeline are obtained.Finally,the test system of damping pipeline system with locally laid active constraint layer is built,and the pipeline vibration active control system based on NI PXI platform is developed.The effectiveness and feasibility of ACLD structure for pipeline vibration control are verified by experiments.The effects of ACLD structural parameters and control parameters on its vibration reduction effect under different pipe types are analyzed.Through the research of this paper,the dynamic modeling method of pipeline system with locally laid active constraint layer damping structure is proposed,the influence law of piezoelectric parameters and active constraint layer structural parameters on pipeline vibration control effect is revealed,and the active constraint layer damping pipeline vibration control system based on NI PXIe platform is developed to verify the vibration reduction effect of ACLD structure.The work of this paper can provide technical reference for vibration control of pipeline system.