A new creep damage assessment method for metallic material under variable load conditions at elevated temperature

2019 ◽  
Vol 42 (12) ◽  
pp. 2725-2737 ◽  
Author(s):  
Xu Hu ◽  
Wen Ye ◽  
Xiao Ma ◽  
Ying Song
Keyword(s):  
Elevated Temperature ◽  
Damage Assessment ◽  
Creep Damage ◽  
Assessment Method ◽  
Variable Load ◽  
Metallic Material ◽  
Load Conditions

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.

scholarly journals Study on Creep Damage of Ni-Based Superalloy Caused by Variable Load Conditions at Elevated Temperatures

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6971
Author(s):  
Sunguk Wee ◽  
Keekeun Kim ◽  
Kibum Park ◽  
Changsung Seok
Keyword(s):  
Gas Turbines ◽  
Elevated Temperatures ◽  
Low Cycle Fatigue ◽  
Creep Damage ◽  
Fatigue Tests ◽  
Variable Load ◽  
Test Results ◽  
Nickel Based Superalloy ◽  
Essential Properties ◽  
Load Conditions

Higher fatigue and creep resistance at high temperatures are the essential properties for materials such as those used in gas turbines for power generation and aircraft turbines. Therefore, the nickel-based superalloy CMSX-4 was developed through single-crystal casting to satisfy these requirements. In this study, the CMSX-4 creep test results reported by previous researchers were used to mathematically derive an equation to estimate the amount of creep damage occurring under variable load conditions. In addition, low-cycle fatigue tests were performed, and the effect of creep damage occurring during fatigue on material failure was described.

An intelligent fault diagnosis method based on domain adaptation for rolling bearings under variable load conditions

2021 ◽  
pp. 095440622110329
Author(s):  
Jianqun Zhang ◽  
Qing Zhang ◽  
Xianrong Qin ◽  
Yuantao Sun
Keyword(s):  
Feature Extraction ◽  
Fault Diagnosis ◽  
Domain Adaptation ◽  
Rolling Bearing ◽  
Training Data ◽  
Variable Load ◽  
K Nearest Neighbor ◽  
Target Domain ◽  
Bearing Faults ◽  
Load Conditions

To identify rolling bearing faults under variable load conditions, a method named DISA-KNN is proposed in this paper, which is based on the strategy of feature extraction-domain adaptation-classification. To be specific, the time-domain and frequency-domain indicators are used for feature extraction. Discriminative and domain invariant subspace alignment (DISA) is used to minimize the data distributions’ discrepancies between the training data (source domain) and testing data (target domain). K-nearest neighbor (KNN) is applied to identify rolling bearing faults. DISA-KNN’s validation is proved by the experimental signal collected under different load conditions. The identification accuracies obtained by the DISA-KNN method are more than 90% on four datasets, including one dataset with 99.5% accuracy. The strength of the proposed method is further highlighted by comparisons with the other 8 methods. These results reveal that the proposed method is promising for the rolling bearing fault diagnosis in real rotating machinery.

Methode zur Auslegung von Verzahnungskorrekturen unter Lastkollektivbelastung

Konstruktion ◽  
2019 ◽  
Vol 71 (09) ◽  
pp. 76-81
Author(s):  
Andreas Fingerle ◽  
Michael Hein ◽  
Thomas Tobie ◽  
Michael Otto ◽  
Karsten Stahl
Keyword(s):  
Variable Load ◽  
Eine Hohe ◽  
Load Conditions

INHALT Die Notwendigkeit für Verzahnungskorrekturen im Hinblick auf die Flankentragfähigkeit ergibt sich in Leistungsgetrieben maßgeblich aus den lastbedingten Verformungen der umliegenden Bauteile sowie der Zahn- und Radkörperverformung selbst. Unter Lastkollektivbelastung sind auch diese Verformungen im Betrieb nicht konstant. In dieser Veröffentlichung wird ein Verfahren gezeigt, mit dem eine Flankenkorrektur ermittelt werden kann, die hinsichtlich der Flankentragfähigkeit unter Lastkollektivbelastung optimiert ist. Die gezeigte Methode wurde im Rahmen des FVA- Vorhabens 722/I entwickelt. Die Ergebnisse der Korrektur- bestimmung wurden anhand von Industriebeispielen validiert und weisen eine hohe Übereinstimmung mit den in der Praxis auf Basis von Erfahrungswissen ausgeführten Zahnflanken-korrekturen auf.   A Method to Determine Toothing Corrections under Variable Load Conditions

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.

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