Research On Structural Vibration Reduction Application Based On Energy Transfer And Collision Energy Dissipation Technology

In order to limit the hazards and effects of vibration,structural vibration damping technology came into being,and various damping measures have been adopted in modern engineering.Additional impact dampers are one of the common measures used in passive damping of structures.Impact damper is mainly through a single impactor and the collision between the cavity for energy transfer and consumption,thereby reducing the amplitude of the main vibration system.Impact dampers have been used in the field of structural vibration damping due to their simple structure,the lack of external equipment to provide energy to help the damping device operate normally,and the better damping effect,and have a broad development prospect.This thesis is supported by the general project of Shaanxi Provincial Key R&D Program(2019GY-067),with Euler-Bernoulli cantilever beam as the experimental object。Firstly,the impact damping system is studied through theory,and secondly,the impact dampers are investigated through cantilever beam vibration experiments to study the influence of different influencing factors on the vibration performance of the cantilever beam,and the main work includes:(1)The Euler-Bernoulli cantilever beam used in this thesis is designed.The natural frequency and vibration pattern of the cantilever beam are analysed and studied by means of theoretical calculations,finite element simulations and modal tests using the force hammer percussion method.The results show that the simulated and theoretical calculated values are greater than the experimental values,and that the three data fits better with less error.(2)Using the impact damper consisting of the mass block and the free motion of the particles,the effect of the undamped collision on the damping performance of the impact damper is investigated.It was found that as the particle mass increased,the amplitude of the cantilever beam gradually decreased,but a new high frequency component was generated.For a given steel ball size,the accelerating amplitude of the cantilever beam is increased as the cavity height increases.The cavity height of the 17 mm shock absorber is only achieved when the steel ball is 15 mm,the experiments of other non-damped collision impact damper are enhanced by the cantilever beam amplitudes.(3)To optimize the undamped impact damper,experimental solutions were designed to investigate the effect of the fluid on the shock absorber’s performance,and to analyze the experimental data and the causes of the impact damper,with regard to the damping medium,damping fluid quality,cavity height and steel ball size.It was found that adding damping fluid silicone oil can not only increase the damping of the system,reduce the amplitude of the system,but also absorb high frequency components;the optimal impact damper is composed of steel ball 15 mm,silicone oil 5g,cavity height 35 mm,Compared to light beams,the acceleration amplitude in the time domain is 4.63 g,which decreases by 71.28%.The acceleration amplitude of the main resonance peak in the frequency domain is 2.66 g,which decreases by 74.38%.The maximum kinetic energy decreases by 94.48%,which means that 94.48% of the cantilever beam energy is transferred to the shock absorber,and the vibration reduction effect is good.