scholarly journals Study on Creep Damage Assessment Method for Mod. 9Cr-1Mo Steel by Sampling Creep Testing with Thin Plate Specimen

2019 ◽  
Vol 68 (5) ◽  
pp. 421-428 ◽  
Author(s):  
Hideyuki KANAYAMA ◽  
Noritake HIYOSHI ◽  
Fumio OGAWA ◽  
Mie KAWABATA ◽  
Takamoto ITOH ◽  
...  
Keyword(s):  
Thin Plate ◽  
Damage Assessment ◽  
Creep Damage ◽  
Assessment Method ◽  
Creep Testing ◽  
Plate Specimen

Creep Damage Assessment Procedure for Weldment Parts of P91 Boiler Piping in USC Plants: Part II—Validation of a Creep Damage Assessment Method Based on Void Growth Simulation

2011 ◽  
Author(s):  
Takashi Ogata ◽  
Takayuki Sakai ◽  
Masatsugu Yaguchi ◽  
Katsuaki Hoshino
Keyword(s):  
Heat Affected Zone ◽  
Void Growth ◽  
Damage Assessment ◽  
Thermal Power ◽  
Creep Damage ◽  
Simulation Method ◽  
Assessment Method ◽  
Growth Behavior ◽  
Assessment Procedure ◽  
Growth Simulation

Clarification of creep damage mechanisms and establishment of remaining life prediction methods of weldment parts of P91 boiler pipings are important subjects to maintain reliable operation of boilers in thermal power plants. In order to develop a creep damage assessment method of weldment parts of P91 pipings, internal pressure creep tests were conducted on P91 steel longitudinally welded tubes and a previously proposed void growth simulation method is applied to predict void growth behavior. Failure occurred at the heat affected zone without significant deformation. It was found from observation of creep damage interrupted specimens that initiation of creep voids concentrated at the mid-thickness region rather than the surface. It was suggested that triaxial stress states caused acceleration of creep damage evolution in the heat affected zone resulting in internal failure of the tube specimens. Void growth behavior in the heat affected zone was well predicted by the previously proposed void growth simulation method. The void growth prediction method is applied to predict creep damage induced by void initiation and growth in a weldment part of an actual P91 pipe. From comparison of void number density between measurement for a weldment part of a retired elbow pipe and prediction by the simulation, good agreement is obtained indicating the void growth simulation method can be applied to creep damage assessment of weldment parts in actual boiler piping.

Measurement of creep deformation of ex-service 12% Cr steel using digital image correlation

2020 ◽  
Vol 55 (3-4) ◽  
pp. 71-85
Author(s):  
Melody van Rooyen ◽  
Thorsten Hermann Becker ◽  
Johan Ewald Westraadt ◽  
Genevéve Marx
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Damage Assessment ◽  
High Stress ◽  
Creep Damage ◽  
Creep Testing ◽  
Image Correlation ◽  
Dislocation Creep ◽  
Creep Curves ◽  
Service Exposure

The effective operation of ageing coal-fired power plants requires routine damage assessment of critical component materials throughout their service history. Traditional post-exposure mechanical testing typically requires large amounts of material for each testing condition. This study introduces an accelerated (high stress and temperature) creep testing technique that employs digital image correlation for strain measurement over a non-uniform temperature field generated by a thermomechanical tester. When applied to different ex-service (exposed to service conditions within a power plant) 12% Cr piping steels, multiple accelerated creep curves at temperatures ranging from 550°C to 600°C are measured from a single specimen for each material condition. Higher creep damage in the steel due to longer service exposure and higher void densities is revealed by shorter rupture times, faster creep rates and tertiary-dominated creep curves when compared to the lower creep damage state. Microstructural study via quantitative electron microscopy confirms the dislocation creep-driven growth of subgrains in the specimen gauge regions relative to the grips. Larger subgrains and a weakening of precipitate distributions for the high damage material were also noted. Digital image correlation–measured strains are in good agreement with traditional techniques of creep testing with standard extensometry. On a comparative basis, the technique is shown to be a plausible form of damage assessment of 12% Cr piping steels with varying levels of service exposure and serve as a suitable mechanical complement to the traditional void replica methodology.

Ultrasonic Creep Damage Detection by Frequency Analysis for Boiler Piping

2006 ◽  
Vol 129 (4) ◽  
pp. 713-718 ◽  
Author(s):  
Hiroaki Hatanaka ◽  
Nobukazu Ido ◽  
Takuya Ito ◽  
Ryota Uemichi ◽  
Minoru Tagami ◽  
...  
Keyword(s):  
Power Generation ◽  
High Temperature ◽  
Damage Detection ◽  
Fossil Fuel ◽  
Creep Damage ◽  
High Energy ◽  
Assessment Method ◽  
Nondestructive Method ◽  
Fuel Combustion ◽  
Fossil Fuel Combustion

Boiler piping of fossil-fuel combustion power generation plants are exposed to high-temperature and high-pressure environments, and failure of high-energy piping due to creep damage has been a concern. Therefore, a precise creep damage assessment method is needed. This paper proposes a nondestructive method for creep damage detection of piping in fossil-fuel combustion power generation plants by ultrasonic testing. Ultrasonic signals are transformed to signals in a frequency domain by Fourier transform, and a specific frequency band is chosen. To determine the creep damage, the spectrum intensities are calculated. Calculated intensities have a good correlation to life consumption of the weld joints, and this method is able to predict the remaining life of high-temperature piping, which has been already installed.

scholarly journals Rapid Assessment Method of Flood Damage Using Spatial-Statistical Models

2016 ◽  
Vol 8 (4) ◽  
pp. 46
Author(s):  
Abdul Hamid Mar Iman ◽  
Edlic Sathiamurthy
Keyword(s):  
Natural Disaster ◽  
Damage Assessment ◽  
Flood Hazard ◽  
Rapid Assessment ◽  
Assessment Method ◽  
Flood Damage ◽  
The State ◽  
Property Damage ◽  
Rapid Assessment Method ◽  
Spatial Approach

Attention to damage assessment is always a priority especially in cases of natural disaster. The state of Kelantan is known to be one of a few Malaysian states with noticeable natural disaster, in particular, flood. In December 2014, an extraordinary magnitude of flood – nicknamed as yellow flood – struck the state causing hundreds of million ringgit of damage to properties. The purpose of this study is to demonstrate a spatial approach to estimating property damage incurred by flood. By selecting a badly affected area, GIS was used to map geo-referenced flood-hit location in Kuala Krai, Kelantan. Flood hazard was modelled and superimposed on estimated property damage. GIS spatial technique was then employed to estimate the flood damage incurred. This study, however, did not make a complete damage assessment of the properties but rather focusing on the methodology of damage assessment to show how it can be implemented. In conclusion, GIS spatial technique can generally be used to provide flood damage rapid assessment method.

scholarly journals Structural Seismic Damage Assessment Method Based on Structural Dynamic Characteristics

2022 ◽  
Author(s):  
Mingzhen Wang ◽  
Lin Gao ◽  
Zailin Yang
Keyword(s):  
Damage Assessment ◽  
Seismic Damage ◽  
Assessment Method ◽  
Frame Structure ◽  
Fundamental Period ◽  
Deformation Pattern ◽  
Seismic Action ◽  
Building Structure ◽  
Structural Dynamic ◽  
Seismic Damage Assessment

Abstract The seismic damage state of building structure can be evaluated by observing the fundamental period change of structure. Firstly, the fundamental period calculation formula that adapts to the deformation pattern and distribution mode of horizontal seismic action for reinforced concrete frame structure is derived. Secondly, the seismic damage assessment standard of building structure considering period variation is established. Then, the seismic damage assessment method of building structure is constructed. Finally, the seismic damage example is used to verify the established evaluation method. The results show that the established research method has high accuracy and good engineering practicability.

scholarly journals Damage Assessment of Reinforced Concrete Structures: A Review

2022 ◽  
pp. 1-7
Author(s):  
Gomasa Ramesh ◽  
Keyword(s):  
Reinforced Concrete ◽  
Damage Assessment ◽  
Structural Damage ◽  
Concrete Structures ◽  
Practical Method ◽  
Assessment Method ◽  
Reinforced Concrete Structures ◽  
Current Response ◽  
Damage Indices ◽  
Seismic Damage Assessment

Damage may be assessed using several damage indices with values associated with different structural damage states. The usefulness of a variety of current response-based damage indices in seismic damage assessment is addressed and critically assessed. A novel rational damage assessment method is provided, which measures the structure’s physical reaction characteristics. A practical method based on various analyses is given to evaluate the damaged structures in earthquakes of different intensities. This paper provides an overview of previous research works on the damage assessment of the reinforced concrete structures. This study may be helpful for easy understanding about the damage assessment of reinforced concrete structures and reduce the impacts of disaster and surrounding structures.

scholarly journals Creep Damage Assessment of High Chromium Steel Forging through EBSD Method and Hardness Measurement

2008 ◽  
Vol 74 (739) ◽  
pp. 323-328 ◽  
Author(s):  
Kazunari FUJIYAMA ◽  
Keita MORI ◽  
Daisuke KANEKO ◽  
Takahide MATSUNAGA ◽  
Hirohisa KIMACHI
Keyword(s):  
Damage Assessment ◽  
Creep Damage ◽  
Hardness Measurement ◽  
Chromium Steel ◽  
High Chromium ◽  
Steel Forging ◽  
Ebsd Method
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