Modal Analysis And Nonlinear Extension Mechanism Of Linear-Arched Composite Beam

Microelectronic equipment and wireless sensing technology have strongly supported the rapid development of online monitoring technology for the operation status of underground equipment in coal mines,but the problem of the energy supply of wireless monitoring nodes is the bottleneck of its development.In recent years,with the increasing demand for sustainable self-powered power in microelectronic equipment systems,the use of new energy sources(such as solar energy,wind energy,mechanical vibration energy,etc.)to replace the previous chemical batteries to power micro devices has attracted widespread attention.Mechanical vibration energy is less affected by the environment and is an ideal recyclable energy source with a wide range of applications.Aiming at the problem of the recycling of mechanical vibration energy and the difficulty of online monitoring and power supply for underground equipment in coal mines,the research team designed a bistable piezoelectric energy harvester,which can achieve high-efficiency energy harvesting in a wide low-frequency range.Based on the previous research on the linear-arch composite beam bistable piezoelectric energy harvester,this paper optimizes the design of the energy harvester by studying the modal function of the composite beam,the nonlinear response mechanism of the material,and establishes the corresponding mathematical model of the system to reveal The system response law of bistable piezoelectric energy harvester under random excitation lays a theoretical foundation for its industrial application.With the help of ANSYS simulation software,the paper studied the influence of linear-arch composite beams on the frequency and amplitude of piezoelectric energy harvesting system under different thicknesses,different widths,and different masses of the end masses,optimized the cantilever beam size,and developed composite beams Research on modal function,nonlinear analysis of materials,and response characteristics of piezoelectric energy traps under random excitation.Aiming at the inaccuracy of the bistable piezoelectric energy harvester model,the modal vibration shape of the linear-arch composite beam was studied.According to the modal expansion method,the vibration differential equation of the linear-arch composite beam is established,the boundary conditions are set to numerically solve the modal function,and the first-order modal function modal diagram is drawn;the ANSYS finite element simulation software is used to model the cantilever beam.Analyze the modal and compare the first-order modal diagram with the numerical solution results.Finally,the accuracy of the model is verified by experimental tests.To study the nonlinear response mechanism of piezoelectric materials to bistable piezoelectric energy harvesters.Based on the piezoelectric constitutive equation,a linear-arch composite cantilever beam nonlinear dynamic model that only considers the nonlinearity of the piezoelectric material(ignoring the nonlinear magnetic force)is established,and the multi-scale method is used to analyze the model for stability analysis and steady-state solution response.Characteristic analysis and numerical verification reveal the influence of piezoelectric material nonlinearity on piezoelectric energy harvesting system.Aiming at the multi-directional,random and variable problem of underground coal mine vibration excitation,the response characteristics of piezoelectric energy traps under random excitation are studied.The magnetic dipole method is used to establish a magnetic field nonlinear model,and Gaussian white noise simulation is used as a random excitation signal to establish a dynamic model of a bistable piezoelectric energy trap under random excitation;using Fokker-Planck-Kolmogo Analytical model of Love(FPK)equation to obtain the response probability density function of the system.By ignoring the high-order cumulant truncation method,the power spectral density function of the system is obtained;simulation analysis reveals the bistable piezoelectric energy harvester under random excitation Response characteristics under different magnetic distances and different excitations.Finally,build a linear-arch composite beam bistable piezoelectric energy capture system experimental performance test platform,apply random excitation signals to the energy capture device,and obtain the response characteristics of the piezoelectric energy capture system under different magnet spacing and different excitation intensity conditions.Verify the above theoretical results.