Investigate the Effect of Support on Damage Detection in Plates, Using Two-Dimensioal Discrete Wavelet transform
Subject Areas : Vibration Transmisionمجتبی حسینی 1 , امیرمحمد امیری 2 , پیمان بیرانوند 3 , محمد حسین ناصری فرد 4
1 - مدرس دانشکده فنی دانشگاه لرستان و ریاست دانشکده فنی
2 - مدرس دانشکده فنی
3 - مدرس دانشگاه
4 - کارشناس ارشد سازه
Keywords: Wavelet Transform, Plate, Damage Detection, Crack,
Abstract :
To ensure the safety of structures and their serviceability for the sightly purposes, all structures, especially important structures, needs continuous and regular evaluation and monitoring. For this reason, methods for monitoring and damages detection in structures, has emerged. In this article, using wavelet transform method, damages detection in plates with different supporting conditions, is discussed. For this reason, a squre plate with one meter side is considered and supposes its support conditions as four fixed sides, four bearing sides, three fixed sides and cantilever. Damages modeled by rectangular cracks with thickness reduction method. For each supporting state, cracks with different depth checked. Finally, obtained responses from plate finite element analysis, using two-dimensional discrete wavelet transform, analyze and detectable most shallow crack, at any supporting state, is obtained. It can be seen that, this method shows the crack locations by peak points and abrupt changes in wavelet coefficient graph, and that in four fixed sides state, cracks down to one percent relative depth, in three fixed sides state, cracks down to three percent relative depth, in four bearing sides state, cracks down to six percent relative depth and in cantilever state, cracks down to 30 percent relative depth, are detectable. It can be seen that, by increasing the plate fixity, ability of the proposed method to detect tiny cracks will further. The obtained results are useful for design and evaluation of plate form structures and prevent the formation and progression of tiny cracks.
