Test Research on Measurement Parameters of Digital Image Applied to Fatigue Monitoring
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摘要:
钢构件的疲劳监测是钢结构健康监测系统的重要组成部分,而在近年图像采集和数据远程传输技术迅速发展的大环境下,将非接触式数字图像测量和识别技术应用于疲劳监测的研究和进展,受到各方专业人士的关注。为实现通过对数字图像中某种参数变化的识别,在出现可辨识的裂纹之前监测到疲劳异常的目标,设计并加工了Q345qD试件进行疲劳试验。试验过程中采用ARAMIS非接触式三维光学测量系统对观测区域进行动态连续拍照,获得疲劳全过程图像,并将图像在测量系统内部转换为数字作为检测量。对比分析疲劳全过程图像所能够获取的力学指标和获取方法,研究数字图像应变及位移参数的形态和应用可行性;对比静载试验中电测应变片与图像应变测量结果,确定非接触式数字图像测量是否满足应用精度要求;研究试件疲劳过程的应变和位移变化规律,对图像的各种数据进行疲劳过程敏感性分析,研究最优参数指标,确定特征点数据提取方案;验证数字图像技术应用于疲劳监测的可行性和实施方案,兼顾客观性和自动化。
研究表明:通过ARAMIS三维数字图像测量系统能够非接触动态采集测量表面的图像数据,所获取其中任意点的三维应变值和位移值满足精度要求;采用提取截面线均值方法能够有效获取钢构件截面名义应变;通过ARAMIS三维数字图像测量系统能够动态采集测量表面的应变图像数据,获取其中任意点的三维应变值和位移值,由位移指标得到的疲劳异常信息相对较晚,不适合作为疲劳监测的测量参数;确定采用数字图像的应变参数进行疲劳监测具有可行性,提出可在应变等值云图上截取最大应变特征值作为疲劳监测数值系列。所得到的测量数据客观有效、实施性强,是数字图像应用于疲劳监测的最优测量参数。-
关键词:
- 黑白散斑 /
- 应变 /
- 疲劳试验 /
- ARAMIS光学测量系统
Abstract:Fatigue monitoring of steel structure is an important part of steel structure health monitoring system.In recent years,under the rapid development of image acquisition and data remote transmission technology,the application of non-contact digital image measurement technology in fatigue monitoring has attracted the attention.In order to achieve the goal of detecting the fatigue anomaly by means of the identification of certain parameter changes in the digital image before the appearance of identifiable cracks,Q345qD steel specimens were designed and processed for fatigue test.During the test,the ARAMIS optical measurement system was used to take pictures of the observation area dynamically and continuously to obtain the whole fatigue process image,and the image was converted into data inside the measurement system as the measured value.By comparing and analyzing the mechanical indexes and collection methods during the whole fatigue process,the shape and application feasibility of the strain and displacement parameters of the digital image were studied.Comparing the results of electrical strain gauge with image strain measurement in static load test to make sure that the accuracy of digital image measurement was satisfied or not.The strain and displacement changes of the specimen during fatigue process were studied.The sensitivity analysis of various parameter of the image with fatigue process was carried out.The optimal parameter index and the way to collect them were studied.Finally,the feasibility and implementation scheme of the application of digital image technology to fatigue monitoring are verified meanwhile both of objectivity and automation were in consideration.
It was shown that the ARAMIS optical measuring techniques can collect dynamically the image data of the measured surface without contact.The obtained 3D strain values meet the accuracy requirement.The nominal strain of cross-section can be obtained by average value method of cross section line.The fatigue abnormal information obtained from the displacement parameter is relatively late,which is unacceptable for fatigue monitoring.While it is acceptable to take the strain parameter as the monitoring object of digital image.It is proposed that the maximum strain eigenvalue on the equivalent cloud image can be intercepted as a numerical series for fatigue monitoring.The obtained data are objective,effective and practical,and are the optimal measurement parameters for the application of digital image to fatigue monitoring.-
Key words:
- black and white speckle /
- strain /
- fatigue test /
- ARAMIS optical measuring techniques
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[1] 莫国影,左敦稳,黎向锋.基于CCD图像的表面疲劳裂纹检测方法[J].机械制造与自动化,2008,37(6):55-57, 59. [2] 莫国影,左敦稳,朱笑笑.基于CCD图像的表面疲劳裂纹识别与长度计算[J].机械制造与自动化,2008,37(2):66-68. [3] 孟兆新,张绍群,张嘉振.基于边缘检测的微小疲劳裂纹图像数据提取[J].东北林业大学学报,2006,34(3):111-112. [4] 杨茜.基于图像处理的金属铜构件疲劳裂纹缺陷识别方法研究[J].世界有色金属,2016(8下):88-89. [5] 高红俐,郑欢斌,姜伟,等.基于图像处理的疲劳裂纹扩展长度在线测量方法[J].中国机械工程,2016,27(7):917-924. [6] 郑欢斌,刘辉,刘欢,等.疲劳裂纹扩展试验裂纹图像采集系统[J].轻工机械,2015,33(6):46-55. [7] Cikalova U, Kroening M, Schreiber J, et al. Evaluation of Al-specimen fatigue using a "smart sensor"[J]. Physical Mesomechanics, 2011,14(5):308-315. [8] 彭红春. Q235钢带缺口试件疲劳裂纹扩展分形分析[J].机械工程师,2013(9):19-20. [9] Zhang C, Chen Y H, Yao W X. The use of fractal dimensions in the prediction of residual fatigue life of pre-corroded aluminum alloy specimens[J]. International Journal of Fatigue, 2014,59:282-291. [10] 周忠良,顾家琳,陈南平.显微网格数字图像处理方法及其在微区变形场测量中的应用[J].理化检验-物理分册,1994,30(3):33-35. [11] Dunand M, Roth C, Mohr D. Effect of strain rate on ductile fracture of acvangced high sthength steels[C]//13th International Conference on Fracture (ICF13). Beijing:2013:S24-013. [12] 陈岚树,董军,彭洋,等.用于残余应力现场检测的DIC-盲孔法研究进展[J].建筑钢结构进展,2014,16(3):37-44. [13] 李亚波,杨凯,陈一萍.基于轮轴疲劳试验台的ARAMIS光学测量系统的应用[J].计算机应用,2016(4):37-38,48. [14] 熊拥军,刘同成,闫小青,等. ARAMIS应变测量系统在铝合金材料拉伸试验中的应变测量系统在铝合金材料拉伸试验中的用[J].塑性工程学报,2018(4):298-304. [15] 白晓虹.数字图像相关(DIC)测量方法在材料变形研究中的应用[D].沈阳:东北大学,2011.
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