کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8130723 1523213 2015 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A time-domain synthetic aperture ultrasound imaging method for material flaw quantification with validations on small-scale artificial and natural flaws
ترجمه فارسی عنوان
یک روش تصویربرداری اولترا سایزر دیافراگم مصنوعی زمان محدوده اندازه گیری خرابی با اعتبار سنجی در نقاط ضعف مصنوعی و طبیعی مقیاس کوچک
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم آکوستیک و فرا صوت
چکیده انگلیسی
A direct time-domain reconstruction and sizing method of synthetic aperture focusing technique (SAFT) is developed to improve the spatial resolution and sizing accuracy for phased-array ultrasonic inspections. The basic idea of the reconstruction algorithm is to coherently superimpose multiple A-scan measurements, incorporating the phase information of the sampling points. The algorithm involves data mapping and in-phase summation according to time-of-flight (TOF). Data mapping refers to the process of placing each of the sampling points to a two-/three-dimensional grid that represents the geometry model of the object being inspected. The value for each of the cells of the grid is a summation of all sampling points mapped into the cell. A sizing method based on the concept of 6 dB-drop is proposed to characterize the flaw boundary. The extents, orientation and the shape of the flaw can then be inferred to provide more information for life assessment calculations. Lab experiments are performed using a 10 MHz phased-array ultrasonic transducer to collect data from a cylinder material block with closely spaced artificial flaws and from a material block with a natural flaw. The developed method is used to process the experimental data to characterize the flaws. Using the developed method, the improvement of spatial resolution is observed. Results indicate that four closely spaced 0.794 mm-diameter flat-bottomed holes are clearly identified, and the quantification of size and orientation of the natural flaw is very close to the actual measurement made from digital microscopy after cutting the testing piece apart.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ultrasonics - Volume 56, February 2015, Pages 487-496
نویسندگان
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