薄壁球壳受刚性平面压缩的连续变形测量

建立了非接触光学测量实验系统,对薄壁球壳受刚性平面压缩的连续变形及失稳行为进行了实验研究。实验以理想弹塑性材料制成的薄且壁厚均匀的乒乓球为压缩对象,采用透明石英玻璃板作为刚性平面,用相机透过玻璃板采集清晰的散斑图像。然后利用具有非接触、全场、高精度等优点的三维数字图像相关(3D-DIC)技术对与刚性平面接触的乒乓球表面的连续变形进行直接测量,同时利用二维数字图像相关技术结合压力传感器得到对应的力-位移关系。实验研究表明,基于3D-DIC方法测量三维表面变形场,实现了对受刚性平面压缩的乒乓球表面从局部压平阶段到轴对称屈曲阶段,进而演化到非轴对称屈曲阶段等力学行为的可视化。实验结果表明,对乒乓球半径的测量精度可达0.5%,利用Abaqus有限元方法得到的结果与实验结果非常吻合,验证了所提方法的有效性。

Research and Monitoring of Metro Tunnel Deformation based on the Technology of the Internet of Things

After a long subway tunnel operators will produce cross-sectional deformation. Articles designed vehicle laser ranging device tbr continuous measurement of tunnel wall to test their defomaed state. The paper also describes the tunnel cross-section deltbrmation measurement method, contour titting principles and error analysis and networking technology for wireless data transmission methods. The detection system is designed to achieve a tunnel section of the structural safety testing and deformation that may occur timely disaster warning, the safe operation of the subway tunnel to provide effective protection.