Investigation of the R260 Rail Steel Behavior at Varying Temperatures by EMI Method

Öz

In recent years, Electromechanical Impedance (EMI) method has been widely used in structural health monitoring (SHM). In this method, lead zirconate titanate (PZT) ceramic sensor patch is added to the structure to be monitored for structural health. Impedance and admittance characteristics are measured using an impedance analyzer, which forms the reference characteristic in the evaluation of structural health. It is expected that these characteristics will not change as long as there is no change in the structure. However, it is known that these characteristics change in some situations, such as exposure to external environmental conditions and temperature fluctuations. If the effect of temperature is not taken into account, it leads to misinterpretations as if there were faults in the structure. Rails are exposed to changing environmental conditions continuously. In this study, the behavior of the R260 rail steel at varying temperatures is investigated using the EMI method. As a result of the experimental studies, it has been observed that frequency and amplitude change with decreasing temperature. This change has been interpreted using damage metrics. 

Anahtar Kelimeler

• EMI method,temperature effect,rail

R260 Ray Çeliğinin Değişen Sıcaklıklardaki Davranışının EMI Yöntemi ile İncelenmesi

Öz

Yapısal sağlık izleme (SHM)’de son yıllarda Elektromekanik Empedans (EMI) yöntemi yaygın olarak kullanılmaktadır. Bu yöntemde yapısal sağlığı denetlenecek yapıya kurşun-zirkonat-titanat (PZT) seramik sensör yaması eklenir. Empedans analizör kullanılarak empedans ve admittans karakteristikleri ölçülür. Bu ölçümler yapısal sağlığın değerlendirilmesinde referans karakteristiğini oluşturur. Bu karakteristiklerin yapıda hata, kusur vb. olmadığı sürece değişmemesi beklenir. Ancak değişen çevresel koşullar ve sıcaklık dalgalanmaları gibi bazı durumlarda bu karakteristiklerin değiştiği bilinmektedir. Eğer sıcaklık etkisi dikkate alınmazsa, yapıda hata, kusur vb. olmadığı halde varmış gibi yanlış yorumlamalara yol açar. Raylar sürekli olarak değişen çevresel koşullara maruz kalmaktadır. Bu çalışmada, R260 ray çeliğinin değişen sıcaklıklardaki davranışı EMI yöntemi kullanılarak incelenmiştir. Yapılan deneysel çalışmaların sonucunda, sıcaklık azaldıkça frekans ve genliğin değiştiği gözlenmiştir. Bu değişim hasar metrikleri kullanılarak yorumlanmıştır.

Anahtar Kelimeler

• EMI yöntemi,sıcaklık etkisi,ray

Kaynakça

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