کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
774073 1462992 2013 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Failure analysis of a high pressure natural gas pipe under split tee by computer simulations and metallurgical assessment
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی صنعتی و تولید
پیش نمایش صفحه اول مقاله
Failure analysis of a high pressure natural gas pipe under split tee by computer simulations and metallurgical assessment
چکیده انگلیسی


• Failure analysis of a high pressure gas pipe covered by a split tee.
• Studying the microstructure of the cracked pipe.
• Using stress and dynamic analysis to recognize the critical zones with maximum stress.

Crack failure of a 36 inch high pressure gas pipe observed during regular inspection of a station has been investigated and the results are presented in this paper. The crack, approximately one meter long, was initiated from a notch inside the hot tapped hole in a pipeline installed about 30 years ago. The study was conducted by reviewing the design history and construction data, visual inspection, pipe material characterization, stress and modal analysis by using finite element method. Investigations revealed that the valve, directly connected to the split tee, faced large dynamic periodic forces due to a pressure drop between two pipelines. Metallurgical evaluation of the pipe material by optical microscope and fractography of the crack surface by scanning electron microscopy indicated the presence of elongated inclusions in the steel microstructure together with some indications of fatigue fracture as a poorly formed sawtooth profile. Based on dynamic analysis, it was found that the first mode shape, the maximum displacement and, therefore, the maximum stress were exactly situated within the crack initiation zone. It was concluded that the notch effect in the hot tapped hole, the position of the supports under the split tee and the presence of a large periodic stress were responsible for the initiation and fatigue propagation of the crack in the gas pipe.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Engineering Failure Analysis - Volume 32, September 2013, Pages 188–201
نویسندگان
, , ,