摘要
针对单轴拉伸实验变形精确测量需求,研制出可同步测量试样纵向和横向变形的二维视频引伸计。首先阐明二维视频引伸计工作原理,对其成像系统进行分析和硬件选型;其次,针对二维变形测量设计了目标识别算法,对基于灰度形态学图像预处理、基于金字塔的模板匹配、基于边缘跟踪的直线特征检测和基于ROI的目标识别等子算法进行设计及测试;最后,采用LabVIEW与NI Vision平台开发了具有图像采集、图形标定、视觉检测及曲线分析功能的二维视频引伸计操作软件,并与试验机控制软件集成。以Q235低碳钢为例开展单轴拉伸测试,结果表明:该引伸计可有效跟踪试样标距段纵向及横向变形,在初始和断裂时刻,纵向变形测量相对误差均值均<0.02%,横向变形测量相对误差均值均<0.2%。
In response to the requirement for precise measurement of deformation in uniaxial tension tests,a twodimensional video extensometer capable of simultaneously measuring the longitudinal and transverse deformation of the specimen is developed.Firstly,the working principle of the two-dimensional video extensometer is clarified,and the imaging system is analyzed and hardware selection is also made.Secondly,the target recognition algorithm for synchronous measurement of longitudinal and transverse deformation is designed,and sub-algorithms such as image pre-processing based on grayscale morphology,template matching based on pyramids,straight-line feature detection based on edge tracking,and target recognition based on ROI are designed and tested.Finally,the two-dimensional video extensometer operation software with functions of image acquisition,graphic calibration,visual detection,and curve analysis is developed using LabVIEW and NI Vision platform,which is integrated with the test machine control software.Uniaxial tension tests are carried out on Q235 low carbon steel.The experimental results demonstrate that the video extensometer is capable of accurately monitoring both the longitudinal and transverse deformations within the gauge length of the specimens.Specifically,in the initial and fractured stage,the average relative error margin of longitudinal deformation measurements are less than 0.02%,while the average relative error margin of transverse deformation measurements are less than 0.2%.
作者
陈俊甫
王震涛
陈富宇
马丙辉
刘亚丕
王疆瑛
CHEN Junfu;WANG Zhentao;CHEN Fuyu;MA Binghui;LIU Yapi;WANG Jiangying(College of Materials and Chemistry,China Jiliang University,Hangzhou,Zhejiang 310018,China;Zhejiang Province Institute of Metrology,Hangzhou,Zhejiang 310016,China)
出处
《计量学报》
北大核心
2026年第2期222-229,共8页
Acta Metrologica Sinica
基金
浙江省‘尖兵’‘领雁’研发攻关计划项目(2022C01192)
国家级大学生创新创业训练计划项目(202310356030)
浙江省高校实验室工作研究项目(YB202368)。
关键词
材料变形测量
视频引伸计
目标识别算法
二维变形测量
单轴拉伸实验
material deformation measurement
video extensometer
target recognition algorithm
two-dimensional deformation measurement
uniaxial tension tests
