| In the field of engineering,vibration control has always been a hot topic,and vibration isolation and absorption technology,as the main methods of vibration control,are constantly developing.If the mechanical energy during the vibration control process is collected as the power supply for the sensors on the equipment,it can not only achieve energy reuse but also save the trouble of frequent power supply replacement.The combination of vibration control and vibration energy collection has important practical significance.Considering that the system after vibration isolation still has a large amplitude in the low-frequency region,a new vibration isolation system is composed of a quasi-zero stiffness(QZS)as the main structure,an additional vibration absorption structure,and an energy collection device.Research on vibration control and energy collection is conducted around this type of vibration isolation system,mainly including:Three types of quasi-zero-stiffness isolation systems with energy collection devices have been established.The first type is an isolation system with Voigt type absorption structure and piezoelectric energy collection device under displacement excitation conditions.The second type is an isolation system with damping grounding type absorption structure and piezoelectric and electromagnetic energy collection devices under force excitation conditions.The third type is an isolation system with nonlinear energy sink(NES)absorption structures and piezoelectric under force excitation conditions Vibration isolation system for electromagnetic energy collection devices.The main research focuses on three types of vibration isolation systems to achieve amplitude control and energy acquisition of the main structure.Obtain approximate analytical solutions for the main structural motion of three types of vibration isolation systems,as well as the generated voltage and current values of energy collectors,using the averaging method.Verify the correctness of the analytical solutions by comparing the numerical solutions with the amplitude frequency response maps drawn from the analytical solutions.Using Lyapunov stability theory to analyze the stability of steady-state solutions for three systems.The analytical solution was used to explore in detail the impact of changes in vibration absorption parameters on amplitude suppression and energy acquisition effects.The Runge Kutta method was used to analyze the electrical power and energy acquisition rate generated by the energy collectors of three vibration isolation systems.By comparing the amplitude frequency response of an isolation system with an ordinary quasi-zero-stiffness isolation model with the same parameters under the same excitation conditions,it was verified that the isolation system with an absorption structure and energy collection device has better amplitude suppression effect in the low-frequency region.The first two types of vibration isolation systems using linear vibration absorption form will generate a wave valley when the excitation frequency is equal to the natural frequency of the vibration absorbing structure.Considering the stiffness of piezoelectric materials,the position of the wave valley is slightly larger than the natural frequency of the vibration absorber.Compared with the third system,the second system can better suppress amplitude within a certain frequency range due to its ability to adjust the natural frequency of the absorber.However,the amplitude suppression effect at the second resonance peak position is poor,even inferior to ordinary quasi-zero isolation systems.The third system can have good amplitude suppression effect in all low frequency regions.For energy collection,the first type of isolation system generates an electrical power of about 10 m W from the medium voltage electric energy collector,with an energy collection rate of up to 0.56%.The second type of isolation system can generate maximum power of 0.15 m W and 40 m W for electromagnetic and piezoelectric energy collectors,respectively.After stabilization,the highest conversion rates can reach 0.01%and 5.14%,respectively.The energy collection effect of the third system is poor,and the power generated by both energy collectors is at the micro watt level,with a collection rate much lower than that of the second system.The electromagnetic energy harvester can supplement the insufficient power generated by the piezoelectric energy harvester in the low excitation frequency domain.By comparing the energy conversion analysis with the second type of isolation system under similar working conditions,it was found that most of the vibration energy was rapidly dissipated by NES,resulting in a significant reduction in the collection capacity of piezoelectric energy collectors,while the energy collection effect of electromagnetic energy collectors was not significantly affected.Although the piezoelectric energy acquisition rate of the third system is low,the energy acquisition bandwidth is much larger than that of the second vibration isolation system. |
