Design And Experimental Study Of Mechanical Resonance-Sensitive Element Based On Modal Coupled Vibration

With the advancement of science and technology,resonant sensors are widely used in fields such as automotive intelligence,aerospace,medical electronics,and energy detection.The detection performance of resonant sensors is easily affected by nonlinear factors,and studying the nonlinear effects of complex resonant sensor structures has become an important direction.In order to solve the problems of excellent detection performance,single detection mechanism,and unstable operation of traditional resonant sensors.This article designs a resonant sensing element with multiple degrees of freedom mode coupling,using the modal coupling mechanism of resonant sensitive components to identify external mass disturbances,and proposed a multifunctional detection scheme for quantitative detection and mass warning.This article mainly studies the array resonant structure with external mode coupling,the folded T-type resonant structure with internal mode coupling,and the multi-mode couplingΠ-type vibration characteristics and detection performance of resonant structures.Based on the single detection principle structure,analyze the physical conditions of internal/external modal coupling vibration.Design multimodal coupling Π-shaped resonant sensing element can achieve mass detection based on modal localization effect and threshold detection scheme based on bifurcation jump characteristics.The detailed study content is as follows:(1)Introduced the principles of mechanical piezoelectric drive,quantitative detection,mass warning detection,and the detection characteristics of mechanical resonance sensitive devices.Then,the principle of modal localization,modal coupled,amplitude saturation,and frequency comb phenomenon were described.In addition,the detection methods of quantitative detection and mass warning were summarized,and the advantages,disadvantages,and nonlinear factors of various detection methods were compared and analyzed.(2)A structure of array resonant sensing elements based on external mode coupling was designed,and the inherent characteristics of the resonant structure were analyzed using COMSOL.The physical conditions generated by the 1:1 induced mode localization principle were obtained,and the detection characteristics based on the mode localization principle for quantitative detection were experimentally verified.By establishing a dynamic theoretical model,the frequency response equation was derived.The author studied the vibration characteristics and quantitative detection characteristics of resonant structures without/with tuned mass under different resonance modes,and calculated the sensitivity with vibration amplitude ratio as the output parameter.The experimental results show that the external mode coupled array structure achieves quantitative detection based on the principle of modal localization,and the detection performance can be flexibly changed by adding tuning mass and changing driving conditions.(3)A T-type coupled resonant sensing element structure based on internal mode coupling was designed,and the relationship between the inherent characteristics of the T-type structure and the vertical beam was simulated and analyzed.The clamp of T-type natural frequency error compensation is designed,and the detection characteristics of bifurcation jump behavior used for mass threshold detection are analyzed experimentally.The amplitude frequency characteristics and force amplitude characteristics of T-type are studied experimentally,and the frequency comb phenomenon and complex nonlinear dynamic behavior caused by modal coupling are measured.The experimental results show that the bifurcation behavior induced by internal mode coupled vibration can achieve threshold detection,and single mass warning and dual mass warning detection are proposed.(4)Designed a multimodal coupled Π-type structure of the resonant sensing element,based on an array beam with external mode coupled vibration and a folded beam with internal mode coupled vibration.Utilizing the principle of modal localization and bifurcation jump characteristics to simultaneously achieve quantitative detection and mass warning.Simulation analysis Π-type inherent characteristics of the sensitive element were obtained,and the physical conditions for the first three bending mode frequencies to be approximately 1:1:2modal coupling vibration.The influence of driving voltage and additional mass on bifurcation jump characteristics was explored through experiments,and multiple threshold mass warning schemes and quantitative detection schemes were proposed.The experimental results show that the three threshold mass warning scheme can achieve mass warnings with a detection range of 0-108.8mg,the four threshold mass warning scheme can achieve mass warnings with a detection range of 0-160 mg,and the quantitative detection range is 6.4mg-41.2mg.The combination of mass early warning detection and quantitative detection to form a multi detection principle resonant sensor provides important reference for the future development direction of resonant sensors.