Mechanical Properties And Vibration Reduction Research Of Multi-dimensional Vibration And Mitigation Device For Large-scale Pipeline Structures

The pipeline structure is prone to vibration violently under the effect of external excitation,fluid pulsation,and water hammer,which influencing transportation efficiency and leading to accidents.Therefore,it is required to control the vibration of the pipeline structure.At present,the dampers are usually used to reduce the vibration of the pipeline structure in engineering.However,there is not a method to control the vibration of the pipeline structure from two aspects simultaneously: isolating vibration and mitigating vibration.The multi-dimensional vibration isolation and mitigation device(MVIMD)is designed and manufactured which can control the vibration of pipelines in multiple directions simultaneously.Based on the test results,the mechanical model of MVIMD is established considering load frequency and displacement amplitude.Moreover,the numerical model of the pipeline structure with MVIMD has installed to verify the effectiveness of the device.Finally,in order to achieve the best control effect,the genetic algorithm is used to optimize the design parameters of MVIMD.In view of the above factors,MVIMD had studied and analyzed.The main research works and achievements can be listed as follows:1)The MVIMD has designed and tested.The experimental analysis reveal that the loading frequency and displacement amplitude have significant influence on the properties of the equivalent stiffness and equivalent damping of MVIMD in both horizontal and vertical directions.Additionally,the equivalent stiffness of MVIMD increases with the increasing loading frequencies and decreases with the increasing displacement amplitudes,while the equivalent damping of MVIMD decreases with the increasing loading frequencies,and decreases with the increasing displacement amplitudes.Therefore,the mathematical model of MVIMD should consider the effects of loading frequency and displacement amplitude.2)After analyzing the test data of the horizontal and vertical properties of MVIMD,a modified equivalent standard solid model of MVIMD is established based on the equivalent standard solid model.In order to verify the correctness of the model,the horizontal and vertical properties of MVIMD are identified.The results show that the modified equivalent standard solid model of MVIMD can describe the horizontal and vertical mechanical properties of the device,which can be used for structural dynamic analysis.3)Based on MATLAB and ANSYS,the genetic algorithm is used to optimize the parameters of MVIMD to achieve the best control effect of the acceleration and displacement.The example results show that the parameters of MVIMD obtained by the optimization of genetic algorithm can control the vibration of the pipeline effectively.The innovations of this paper lay in:1)The MVIMD was designed and tested to control the vibration of the pipeline structure.And the effectiveness of the device was verified by numerical simulation.2)The mechanical model of MVIMD is established and the parameters of are identified.The results show that the model can describe the influence of the loading frequency and displacement amplitude.