基于视频图像技术的简支梁动静载试验分析

摘要

A modal analysis is carried out on the vibration of the simply-supported beam with sensors and without sensors by using the new video image technology.The vibration video of simply-supported beam is decomposed into the image by using Matlab software,and the decomposed image is cut out into the region of interest which is processed by graying and binaryzing.In order to be accurate,the acquired whole pixel edge is processed by the sub-pixel,and the sub-pixel time-domain signal is obtained at the lower edge of the beam. The modal analysis of these signal data is carried out to obtain the first three orders of frequencies and vibration forms,which is compared with the finite element model established by Midas and the results obtained by the traditional dynamic load test.After the comparison of the two groups of experiments,the dynamic and static load tests based on video image technology have higher precision and maneuverability than the traditional detection,and it can make up for the shortcomings of the traditional detection.%采用视频图像技术对带传感器和不带传感器的简支梁的振动进行模态分析,采用Matlab软件把简支梁的振动视频分解成图像,对分解得到的图像裁剪出感兴趣区域并进行灰度化和二值化处理.为了精确,对得到的整像素边缘进行了亚像素化处理,得到梁下边缘的亚像素级别的时域信号,对这些信号数据进行模态分析得出前三阶频率和振型,并与Midas建立的有限元模型、传统的动载试验处理得到的结果三者相比对,对比表明,基于视频图像技术的动静载检测有更高的精度和可操作性,可以弥补传统检测的不足.