竹木板材动态模量在线检测系统  

Online detection system for dynamic modulus of bamboo and wood panels

作　　者：赵玮 郑强 徐锋[1] 刘云飞[1] ZHAO Wei;ZHENG Qiang;XU Feng;LIU Yunfei(College of Information Science and Technology,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学信息科学技术学院,南京210037

出　　处：《林业工程学报》2023年第3期150-155,共6页Journal of Forestry Engineering

基　　金：国家重点研发计划(2017YFD0600904)。

摘　　要：竹木板材作为一种原料,被广泛用于生产家具、地板及工程装修等。其中,弹性模量和剪切模量是其重要的力学性能指标。为快速无损测定竹木板材的动态弹性模量和动态剪切模量,设计了一种基于FPGA的板材动态弹性模量和剪切模量测试系统。系统通过全桥电阻应变传感器拾取板材的冲击响应信号,信号经过调理电路放大后输入FPGA开发板,进行模数转换及频谱变换,得到振动信号的一阶模,最后计算得到竹木板材的动态弹性模量和动态剪切模量。为方便用户使用,该系统增加了上位机显示体系,实现信号采集、频谱分析、一阶模提取、模量计算等功能,执行一次测试仅需几秒。为验证测量方案的可行性,与分离刚度法测试进行了对比,其弹性模量的相对误差在0.14%~2.59%,平均误差为1.46%;剪切模量的相对误差在0.32%~7.45%,平均误差为4.18%。实测数据表明,该动态模量在线检测系统可以有效地测量竹木板材的动态弹性模量和动态剪切模量,处理速度快、应用灵活、稳定性强,可满足生产过程的实时检测需求。As raw materials,bamboo and wood panels are widely used in the production of furniture,flooring,and engineering decoration.Among them,the elastic modulus and shear modulus are important mechanical property indexes,and elastic modulus is a physical quantity that reflects the deformation capacity of materials under load,while shear modulus is a physical quantity that reflects the ability of materials to withstand shear strain.The traditional static method for measuring elastic modulus and shear modulus has drawbacks of long measurement time,tedious measurement process,strict requirements on the dimensional specifications of the specimens,and destructive.Dynamic method is suitable for production process detection because of its short measurement time and no damage to materials.At present,the dynamic testing method has become an important means and development direction for the examination of panels modulus.The impact stress wave method is a dynamic nondestructive testing method with the advantages of simple operation and easy testing,which can be used for the determination of elastic modulus and shear modulus of panels.This study developed an online detection system for measuring the dynamic elastic modulus and shear modulus of bamboo and wood panels based on field programmable gate array(FPGA).The system used the full-bridge resistance strain sensor to pick up the impulse response signal of the panels,amplified the signal through the conditioning circuit,and built a programmable on-chip system with the NIOSⅡsoft core processor as the core through the customized A/D module,JTAG,PLL,FIFO and other IP cores inside the FPGA chip.Through the design to complete the analog-to-digital conversion,spectrum transformation,first-order modulus acquisition and modulus calculation and other functions,finally realized the dynamic elastic modulus and shear modulus of bamboo and wood panels online real-time detection.For the convenience of users and the realization of its interactive functions,the system used QT to develop a visua

关 键 词：竹木板材 在线检测 弹性模量 剪切模量 FPGA 

分 类 号：S781.9[农业科学—木材科学与技术]