【作者】 刘强；

【导师】 吴子英；

【作者基本信息】 西安理工大学 ， 机械设计及理论， 2018， 硕士

【摘要】 目前双稳态结构因其能量转换效率高,成为振动能量捕获技术研究的热点。本文提出了一种双级串联式双稳态振动发电系统,利用数值计算和解析分析的研究方法,对系统响应特性进行了研究,主要内容有:将质量-弹簧-阻尼组成的双稳态结构与另一个双稳态能量采集器串联,构成了一种双级串联式双稳态振动发电系统,利用Lyapunov指数研究了激励幅值和系统结构参数对系统做大幅混沌运动的频带的影响。发现随着激励幅值的增大,系统做大幅混沌运动的频带逐渐变宽;随着质量比的增大,系统产生大幅混沌运动的频带逐渐变窄;随着调频比的增大,系统产生大幅混沌运动的频率逐渐变大;主系统非线性刚度比越小,系统发生大幅混沌运动越困难,但是系统逃离势阱的能量更大。采用两项谐波平衡法,求解系统动力学方程,研究了激励幅值与结构参数对系统输出功率的影响。随着质量比的增大,系统的输出功率逐渐减小,激励幅值越大,系统的输出功率越大;随着调频比的增大,系统的输出功率表现出先增大后减小的趋势,随着激励幅值的增加,系统的输出功率逐渐增大,能产生较大输出功率的调频比逐渐变大;当激励幅值较小时,随着主系统非线性刚度比的变化,系统的输出功率表现出先增大后减小的趋势,当激励幅值较大时,系统的输出功率随着主系统非线性刚度比的增大而逐渐减小。利用数值法研究了有色噪声激励下,噪声强度、系统初始状态与结构参数对系统发电性能的影响规律。随着噪声强度的增大,系统输出功率逐渐增大;初始位移离稳定平衡点越远,系统的越容易跃过平衡点做大幅运动,系统的输出功率越高;系统的初始速度越大,系统的发电效率越高;系统的平均输出功率随着质量比的增加而逐渐减小;系统的输出功率随着主系统非线性刚度比的增大表现出先增大后减小的趋势。通过上面的工作,比较全面的得到了双级串联式双稳态电磁振动系统动力学特性和发电特性,为双级串联式双稳态系统的进一步研究提供了一定的理论基础。更多还原

【Abstract】 At present,on the vibration energy capture technology,the bistable structure has become a hot spot because of its high energy conversion efficiency.In this paper,a two-stage series bistable vibration power generation system is proposed.By using numerical calculation and analytical analysis methods,the system response characteristics are studied.The main contents are as follows:The two-stage series bistable vibration power generation system is composed by the bistable structure of mass-spring-damping and another bistable energy harvester.Besides,Lyapunov exponent was used to study the effect of excitation amplitude and system structure parameters on the frequency bands of the system with large chaotic motions.It is found that as the amplitude of the excitation increases,the frequency band for large chaotic motions of the system gradually becomes wider;with the mass ratio increasing,the frequency band of system that generate large chaotic motions gradually become narrow;with the increasing of the frequency modulation ratio,the frequency of large chaotic motion of the system gradually increasing;the bigger for the depth of the system potential well,the smaller for the nonlinear stiffness ratio of the main system,and the more difficult for the system to do large chaotic motion,however,the energy of the system escape potential well is greater.By using two harmonic balance methods to solve the system dynamics equations,the effect of the excitation amplitude and structural parameters on the output power of the system was studied.As the mass ratio increasing,the output power of the system gradually decreasing,and the larger the excitation amplitude,the greater the output power of the system;with the increasing of the frequency modulation ratio,the output power of the system shows the trend of increasing in the beginning and then decreasing,the increasing of the excitation amplitude,the output power of the system gradually increasing,the frequency modulation ratio that can produce large output power gradually larger;when the excitation amplitude is small,with the changes of the nonlinear stiffness ratio of the main system,the output power of the system shows a trend of increasing in the beginning and then decreasing.When the excitation amplitude is large,the output power of the system gradually decreasing with the increasing of nonlinear stiffness ratio of the main system.By using numerical methods under colored noise excitations to studied the effect of noise intensity,system initial state and structural parameters on the system power generation performance.With the increasing of noise intensity,the output power of the system gradually increasing;the farther the initial displacement is from the stable equilibrium point,the easier the system will be.crossed balance points do large movements,the higher the output power of the system,and the greater the initial speed of the system,the higher the power generation efficiency of the system;the average output power of the system gradually decreasing as the mass ratio increasing;with the increasing of the nonlinear stiffness ratio for the main system,the output power of the system shows a tendency that increasing in the beginning and then decreasing.Through the above work,the dynamic characteristics and power generation characteristics of the Two-stage series bistable electromagnetic vibration system are obtained comprehensively,which provides a certain theoretical basis for the further study of the two-stage series bistable vibration power generation system.更多还原