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
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