شناسایی محل تغییر جرم در سازه با استفاده از روش پردازش تصاویر دیجیتال

نوع مقاله : علمی - پژوهشی

نویسندگان

1 دانشجوی دکتری سازه، دانشکده مهندسی عمران، دانشگاه تربیت دبیر شهید رجایی تهران، ایران

2 دانشیار، دانشکده مهندسی عمران، دانشگاه تربیت دبیر شهید رجایی تهران، ایران

چکیده

در حال حاضر برای به دست آوردن خصوصیات دینامیکی سازه‌ها در مهندسی سازه عمدتاً از روابط تجربی و یا مدل‌های ریاضی و نرم‌افزارهای کامپیوتری استفاده می‌شود. این خصوصیات دینامیکی به بسیاری از جزئیات رفتار مصالح و ترکیب سازه بستگی دارد که تمام این جزئیات را نمی‌توان در مدل‌های تحلیلی دخالت داد؛ بنابراین همیشه بین مدل‌های تحلیلی و سازه واقعی اختلافاتی وجود دارد. لذا انجام آزمایش‌های لرزه‌ای بر روی سازه‌ها مطمئن‌ترین روش برای به دست آوردن خصوصیات مذکور بوده و تاکنون روش‌های مختلفی در دنیا برای انجام این آزمایش‌های لرزه‌ای بر روی یک سازه آزمایشگاهی به‌وسیله پردازش تصویر انجام‌شده است. در این مقاله سعی شده محل تغییر جرم در سازه از طریق خصوصیات دینامیکی سازه‌ها با استفاده از پردازش تصویر به دست آید. بدین منظور از سازه فیلم‌برداری شده و تغییر مکان‌های ثبت‌شده به‌عنوان سیگنال‌های ورودی سیستم در نظر گرفته می‌شود، با دو بار مشتق گرفتن از این تغییر مکان‌ها، شتاب سازه به دست می‌آید و با پردازش این شتاب‌ها، زمان تناوب‌های طبیعی و شکل مود سازه استخراج‌شده و با نتایج حاصل از حسگرهای شتاب تعبیه‌شده روی سازه مقایسه گردیده است، درنهایت با استفاده از روش منحنی شکل مود، سازه به همراه حسگر و بدون حسگر، مقایسه شده است و به‌راحتی توانست وجود افزایش جرم در سازه را تشخیص دهد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Investigation of mass change detection utilizing the digital image processing method

نویسندگان [English]

  • amin havaran 1
  • Mussa Mahmoudi Sahebi 2
1 Faculty of Civil Engineering , Shahid Rajaie Teacher Training University, Tehran, Iran.
2 Associate professor, Department of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
چکیده [English]

Currently, to obtain the dynamic properties of structures in structural engineering, experimental relationships, mathematical models and computer software aids are mainly used. These dynamic properties depend on many details about material behavior and the compound of the structures, which could not all be taken into account in analytical models. Therefore, there are always differences between the analytical models and the actual structures. So, seismic tests on structures is the most reliable method for obtaining these properties, so far, various methods have been developed in the world to preform these seismic experiments on the experimental structures such as image processing method. In this paper, the image processing method utilized through the dynamic properties of structures for mass change detection in the structure. For this purpose, a cantilever beam oscillated and the recorded displacements are considered as the inputs of the system identification. By deriving these displacements twice, the acceleration of the structure obtained and by processing these accelerations, natural frequency and shape mode of structure have been extracted and compared with the results of the accelerometer sensors embedded on the structure. Finally, mode shape curvature method utilized and the location of the sensors on the structure has been detected with good accuracy.

کلیدواژه‌ها [English]

  • image processing
  • structural dynamic
  • Mode shape curvature method
  • Dynamic properties of structures
  • Damage detection
[1]           P. Olaszek, (1999), "Investigation of the dynamic characteristic of bridge structures using a computer vision method," Measurement, vol. 25, pp. 227-236, 4/1/.
[2]           A. Wahbeh, J. P. Caffrey, and S. FMasri, (2003), "A vision-based approach for the direct measurement of displacements in vibrating systems," Smart Materials and Structures, vol. PII, pp. 785–794.
[3]           J. Morlier, P. Salom, and F. Bos, (2007), "New image processing tools for structural dynamic monitoring," Key Engineering Materials.
[4]           G. Busca, A. Cigada, P. Mazzoleni, E. Zappa, and M. Franzi, "Cameras as displacement sensors to get the dynamic motion of a bridge," in Bridge Maintenance, Safety, Management, Resilience and Sustainability, ed: CRC Press, 2012, pp. 2835-2841.
[5]           G. Busca, A. Cigada, P. Mazzoleni, M. Tarabini, and E. Zappa, "Static and Dynamic Monitoring of Bridges by Means of Vision-Based Measuring System," in Topics in Dynamics of Bridges, Volume 3: Proceedings of the 31st IMAC, A Conference on Structural Dynamics, 2013, A. Cunha, Ed., ed New York, NY: Springer New York, 2013, pp. 83-92.
[6]           C.-C. Chen, W.-H. Wu, H.-Z. Tseng, C.-H. Chen, and G. Lai, (2015), "Application of digital photogrammetry techniques in identifying the mode shape ratios of stay cables with multiple camcorders," Measurement, vol. 75, pp. 134-146.
[7]           B. Hwa Kim, (2014), "Extracting modal parameters of a cable on shaky motion pictures," Mechanical Systems and Signal Processing, vol. 49, pp. 3-12.
[8]           P. Cawley and R. D. Adams, (1979), "The location of defects in structures from measurements of natural frequencies," The Journal of Strain Analysis for Engineering Design, vol. 14, pp. 49-57, April 1, 1979.
[9]           M. Vejmelka, M. Palus, and K. Susmakova, (2010), "Identification of nonlinear oscillatory activity embedded in broadband neural signals," Int J Neural Syst, vol. 20, pp. 117-28, Apr.
[10]         G. F. Sirca and H. Adeli, (2012), "System identification in structural engineering," Scientia Iranica, vol. 19, pp. 1355-1364.
[11]         M. Kato and S. Shimada, (1986), "Vibration of PC Bridge during Failure Process," Journal of Structural Engineering, vol. 112, pp. 1692-1703.
[12]         M. J. Whelan, M. V. Gangone, K. D. Janoyan, and R. Jha, (2009), "Real-time wireless vibration monitoring for operational modal analysis of an integral abutment highway bridge," Engineering Structures, vol. 31, pp. 2224-2235.
[13]         M. J. Whelan and K. D. Janoyan, (2010), "In-Service Diagnostics of a Highway Bridge from a Progressive Damage Case Study," Journal of Bridge Engineering, vol. 15, pp. 597-607.
[14]         W. M. West, "Illustration of the use of modal assurance criterion to detect structural changes in an Orbiter test specimen," in 4th International Modal Analysis Conference, Los Angeles, CA, (1986), pp. 1-6.
[15]         N. Stubbs, J.-T. Kim, and C. Farrar, "Field Verification of a Nondestructive Damage Localization and Severity Estimation Algorithm," in Proceedings of SPIE - The International Society for Optical Engineering, (1995).
[16]         A. Khadka, Y. Dong, and J. Baqersad, (2019), "Structural Health Monitoring of Wind Turbines Using a Digital Image Correlation System on a UAV," pp. 85-91.
[17]         R. Wu, D. Zhang, Q. Yu, Y. Jiang, and D. Arola, (2019), "Health monitoring of wind turbine blades in operation using three-dimensional digital image correlation," Mechanical Systems and Signal Processing, vol. 130, pp. 470-483.
[18]         D. Reagan, A. Sabato, and C. Niezrecki, (2017), "Feasibility of using digital image correlation for unmanned aerial vehicle structural health monitoring of bridges," Structural Health Monitoring, vol. 17, pp. 1056-1072.
[19]         W. T. F. Encyclopedia. (2013, 8 December 2013). Wikipedia The Free Encyclopedia Image processing. Available: http:// fa.wikipedia.org/wiki/ Image processing
[20]         R. Brincker, L. Zhang, and P. Andersen, (2001), "Modal identification of output-only systems using frequency domain decomposition," Smart Materials and Structures, vol. 10, pp. 441-445.
[21]         D. J. Ewins,  (1984), Modal Testing_ Theory and Practice (Mechanical engineering research studies: Research Studies Press Ltd.
[22]         h. fathi and o. bahar, (2013), "Identification of Modal Parameters of Structures Using Simple and Nonparametric Identification Methods in the Frequency Field with base oscillation," presented at the 15th conference of civil engineering students, oromie university.
[23]         G. G. A‌m‌i‌r‌i, M. T‌a‌l‌e‌b‌i, M. T‌a‌l‌e‌b‌i, and Z. T‌a‌b‌r‌i‌z‌i‌a‌n4, (2013), "D‌A‌M‌A‌G‌E A‌S‌S‌E‌S‌S‌M‌E‌N‌T I‌N C‌O‌N‌N‌E‌C‌T‌I‌O‌N‌S O‌F M‌O‌M‌E‌N‌T R‌E‌S‌I‌S‌T‌A‌N‌T F‌R‌A‌M‌E‌S U‌S‌I‌N‌G H‌I‌L‌B‌E‌R‌T-H‌U‌A‌N‌G rnT‌R‌A‌N‌S‌F‌O‌R‌," Omran Sharif Journal vol. 32.2, pp. 3-11.