A Novel Ultrasonic based NDT for smart analysis of material defects using IoT

Author(s):  
P. Radha ◽  
N. Selvakumar ◽  
J. Raja Sekar ◽  
J. V. Johnsonselva
Keyword(s):  
Author(s):  
Rakesh Yarlagadda ◽  
M. Affan Badar ◽  
Boris Blyukher

The safety of oil and gas pipelines has increasingly considered day by day to their vulnerability. Pipelines play a very critical role in the transportation of oil and natural-gas. As they have become the veins of oil industries, the productive design and analysis became more important. This made them more vulnerable to terrorist attacks. Although it is impossible to design pipelines to withstand any conceivable damage due to external (terrorist attacks, seismic effects) and internal effects (design and manufacturing defects), it is possible to improve the performance of pipelines. By understanding the design criteria, it saves lots of money and more over human lives and also protects the product in pipelines, which cannot be recovered and which is more and more scares day by day. This research aims: 1) to understand the different types of pipeline damages, reasons for their occurrence and their effects on the pipelines, such as mechanical damages, material defects, cracks, manufacturing defects, 2) to understand the explosions in pipelines, internal or external explosions and seismic distress, 3) to do research and literature review in analytical and numerical methods which allow researching the influence of shock waves (explosions, seismic), 4) to develop description of experimental research of pipelines subjected to shock waves (explosions, seismic), 5) to establish an effective methodology (develop mathematical model) to study the risk management in pipeline exploitation which can be subjected to such conditions like shock waves (caused by explosions, seismic, as well as mining activities) on pipeline systems (buried, on surface, or underwater), and 6) to establish criteria for risk management. This paper includes a review of the related literature covering the first two goals.


2016 ◽  
Vol 17 ◽  
pp. 14-30 ◽  
Author(s):  
Okechukwu P. Nwachukwu ◽  
Alexander V. Gridasov ◽  
Ekaterina A. Gridasova

This review looks into the state of gigacycle fatigue behavior of some structural materials used in engineering works. Particular attention is given to the use of ultrasonic fatigue testing machine (USF-2000) due to its important role in conducting gigacycle fatigue tests. Gigacycle fatigue behavior of most materials used for very long life engineering applications is reviewed.Gigacycle fatigue behavior of magnesium alloys, aluminum alloys, titanium alloys, spheroid graphite cast iron, steels and nickel alloys are reviewed together with the examination of the most common material defects that initiate gigacycle fatigue failures in these materials. In addition, the stage-by-stage fatigue crack developments in the gigacycle regime are reviewed. This review is concluded by suggesting the directions for future works in gigacycle fatigue.


Author(s):  
Vamadevan Gowreesan ◽  
Wayne Greaves

A radial steam turbine developed cracks after 220,000 hours of service. The rotor had an integral disc with eight rows of blades, and a short stub. Nine inlets on the disc channeled steam from one side to the other, and then radially outward. Analysis of the fracture surface revealed cracks originating in some of the inlet holes, and propagating by fatigue. No material defects were found at the crack initiation sites. Hardness and microstructure (optical) across the disc were uniform, but chemical composition analysis of the alloy revealed high level of phosphorus and sulfur. In addition, the microstructure consisted of uniformly tempered martensite with manganese sulfide stringers. Although tensile properties were normal, impact testing indicated embrittlement by a shift in Fracture Appearance Transition Temperature (FATT). Metallurgical evidence of embrittlement was also found. It was concluded that service induced cyclic loading in combination with reduced crack resistance caused by embrittlement lead to cracking.


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