Proposal of Creep Remaining Life Assessment Method by using High-Temperature Indentation Creep Test

2017 ◽  
Vol 2017 (0) ◽  
pp. OS1207
Author(s):  
Hiroki YAJIMA ◽  
Kiyohiro ITO ◽  
Masayuki ARAI
Keyword(s):  
High Temperature ◽  
Creep Test ◽  
Assessment Method ◽  
Life Assessment ◽  
Indentation Creep ◽  
Remaining Life ◽  
Remaining Life Assessment

Elevated-Temperature Life Assessment

2021 ◽  
pp. 146-166
Author(s):  
Arun Sreeranganathan ◽  
Douglas L. Marriott
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Stress Relaxation ◽  
Damage Mechanics ◽  
Elevated Temperatures ◽  
Constitutive Models ◽  
Life Assessment ◽  
Remaining Life ◽  
High Temperature Components ◽  
Remaining Life Assessment

Abstract This article provides some new developments in elevated-temperature and life assessments. It is aimed at providing an overview of the damage mechanisms of concern, with a focus on creep, and the methodologies for design and in-service assessment of components operating at elevated temperatures. The article describes the stages of the creep curve, discusses processes involved in the extrapolation of creep data, and summarizes notable creep constitutive models and continuum damage mechanics models. It demonstrates the effects of stress relaxation and redistribution on the remaining life and discusses the Monkman-Grant relationship and multiaxiality. The article further provides information on high-temperature metallurgical changes and high-temperature hydrogen attack and the steps involved in the remaining-life prediction of high-temperature components. It presents case studies on heater tube creep testing and remaining-life assessment, and pressure vessel time-dependent stress analysis showing the effect of stress relaxation at hot spots.

scholarly journals Virtual Remaining Life Assessment of Electronic Hardware Subjected to Shock and Random Vibration Life Cycle Loads

2007 ◽  
Vol 50 (1) ◽  
pp. 86-97 ◽  
Author(s):  
Sony Mathew ◽  
Diganta Das ◽  
Michael Osterman ◽  
Michael Pecht ◽  
Robin Ferebee ◽  
...  
Keyword(s):  
Life Cycle ◽  
Space Shuttle ◽  
Assessment Method ◽  
Life Assessment ◽  
Remaining Life ◽  
Damage Models ◽  
Solid Rocket ◽  
Remaining Life Assessment ◽  
Stress Damage ◽  
Electronic Hardware

This study presents a physics-of-failure-based virtual remaining life assessment method for assessing the remaining life of an electronic circuit card. The approach is then demonstrated through a case study of a circuit card assembly in the Space Shuttle solid rocket booster. Using thermal and mechanical stress damage models, the accumulated damage in the circuit card due to the life cycle environment loads on the card was calculated. Based on the amount of damage accumulated, the remaining life of the circuit card was estimated.

A Remaining Life Assessment for Shell-to-Skirt Juncture of Coke Drum With Crack-Like Flaws

2011 ◽  
Author(s):  
Masaaki Oka ◽  
Himsar Ambarita ◽  
Masashi Daimaruya ◽  
Hiroyuki Fujiki ◽  
Hidetoshi Kobayashi
Keyword(s):  
Crack Size ◽  
Assessment Method ◽  
Life Assessment ◽  
Remaining Life ◽  
Oil Refineries ◽  
Linear Elastic ◽  
Thermal Boundary Conditions ◽  
Operational Life ◽  
Remaining Life Assessment ◽  
In The Beginning

Coke drums are subjected to severe cyclic thermal and mechanical loads, thus their operational life is much shorter than other the conventional pressure equipments in oil refineries. Information developed from surveys indicates that one of major typical locations of failure due to thermal fatigue in coke drums is the shell-to-skirt juncture area. At the outer surface of the upper part of the skirt, there are two peak strains in every cycle which are tensile in the beginning of the filling stage and compressive in the cooling stage. The objective of the present paper is to develop a remaining life assessment method for shell-to-skirt juncture of coke drum with cracks propagated during cyclic operation. A coke drum currently in service with inside diameter of 8.55 m, height of 34.9 m, shell thickness varies from 28.5 mm to 34 mm, and skirt thickness of 24 mm is taken into analyses. In order to get the actual operational characteristics of the coke drum, temperatures and strains on the coke drum have been measured for 100 cycles. The selected operational temperatures will be employed as thermal boundary conditions for analyses. Propagations of 2 mm initial cracks depth at the inner surface of the upper part of the skirt, underneath the juncture as shown in Fig-3, is simulated on the basis of linear elastic fracture mechanics (LEFM). The relations of crack size with the number of operation cycles are plotted.

Life Assessment of Steam-Turbine Components

1989 ◽  
pp. 265-328
Keyword(s):  
High Temperature ◽  
Steam Turbine ◽  
Failure Modes ◽  
Assessment Methods ◽  
Life Assessment ◽  
Remaining Life ◽  
Steam Turbines ◽  
Damage Mechanisms ◽  
Design Considerations ◽  
Remaining Life Assessment

Abstract This chapter covers the failure modes and mechanisms of concern in steam turbines and the methods used to assess remaining component life. It provides a detailed overview of the design considerations, material requirements, damage mechanisms, and remaining-life-assessment methods for the most-failure prone components beginning with rotors and continuing on to casings, blades, nozzles, and high-temperature bolts. The chapter makes extensive use of images, diagrams, data plots, and tables and includes step-by-step instructions where relevant.

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