林业工程学报2025，Vol.10Issue(4)：54-60,7.DOI:10.13360/j.issn.2096-1359.202408006
基于压电阻抗的木材弹性模量检测
Detection of elastic modulus of wood based on the piezoelectric impedance
摘要
Abstract
The elastic modulus is a key indicator of the mechanical properties of wood.The transverse vibration method,which has been standardized,plays a significant role in the dynamic measurement of elastic modulus.However,the existing detection systems are relatively complex and present challenges when attempting to excite small free beam specimens.To further simplify the detection system and facilitate on-site testing,a novel method based on the piezoelectric impedance response of lead zirconate titanate piezoelectric ceramics(PZT)was proposed for the dynamic detection of elastic modulus of wood.Utilizing the analysis model of coupling structure between PZT and beam specimen,the formula for calculating the electrical admittance of PZT was derived,and the feasibility of extracting the first-order bending mode frequency of the PZT-coupled specimen from the impedance response curve was theoretically verified.To improve the measurement accuracy and determine the appropriate scanning range,the specimen size and scanning range of PZT were optimized through modal simulation based on the software of Comsol Multiphysics.The size of the beam specimen was optimized as 250 mm×40 mm×5 mm,and the scanning range was optimized as 300-600 Hz for the impedance response measurement of PZT.The theoretical derivation of the proposed method was based on the rectangular PZT sheets.Since rectangular PZT sheets require customization,leading to high costs,and circular PZT of buzzer sheets are more affordable,impedance simulations and tests were conducted to verify the effectiveness and practicability of the PZT impedance method.These tests confirmed that circular PZT patches were also suitable for the dynamic detection of the elastic modulus of wood.Three wood species were selected for the simulation study.The simulation results showed that the circular PZT patch can effectively excite the first-order bending mode of PZT-coupled specimens during the impedance analysis,there was a unique peak in the real part response curve of the PZT impedance with the optimized scanning frequency range,and the peak frequency was the first-order bending mode frequency of the PZT-coupled specimen,with which the dynamic elastic modulus of wood was calculated.The maximum relative error of the simulation results was only 1.59％.Six species of wood were chosen for experimental study.The experimental results showed that the first-order mode frequency of PZT-coupled beam specimens can be extracted through the impedance response curve,and the maximum relative error was only 1.09％.Both simulation and experimental results validated the effectiveness of the PZT impedance method.关键词
锆钛酸铅压电陶瓷/压电阻抗/木材/弹性模量/弯曲模态Key words
PZT/piezoelectric impedance/wood/elastic modulus/bending mode分类
信息技术与安全科学引用本文复制引用
蒋陈侃,徐广洲,李绍成..基于压电阻抗的木材弹性模量检测[J].林业工程学报,2025,10(4):54-60,7.基金项目
国家重点研发计划(2022YFD2200705). （2022YFD2200705）
