Life Prediction in High-Temperature Structural Materials

1995 ◽  
Vol 117 (1) ◽  
pp. 1-6 ◽  
Author(s):  
C. E. Jaske
Keyword(s):  
High Temperatures ◽  
Life Prediction ◽  
Critical Size ◽  
Structural Materials ◽  
Prediction Methods ◽  
Engineering Systems ◽  
Degradation Mechanisms ◽  
Initial Size ◽  
Materials Used ◽  
Cycle Dependent

Life prediction methods are required to assess the performance and safety of the structural materials used in engineering systems and components that operate at high temperatures. At high temperatures, materials are subject to time-dependent creep environmental degradation, as well as cycle-dependent fatigue degradation. The life prediction methods must account for all of these degradation mechanisms and their possible interactions. The purpose of this paper is to review the methods that are used predict the creep and fatigue life of structural materials. Traditional methods that have been used to predict the life of structural materials are based on the initiation of a significant crack; whereas more recent methods employ fracture mechanics to predict life based on the growth of crack from some initial size to a critical size. Crack-growth-based life prediction methods are emphasized in this review.

scholarly journals Method for Dynamic State Monitoring of Pressure Vessel

2013 ◽  
Vol 330 ◽  
pp. 454-459
Author(s):  
Xue Rong Ma
Keyword(s):  
Nondestructive Test ◽  
Nondestructive Testing ◽  
Pressure Vessel ◽  
Life Prediction ◽  
Critical Size ◽  
Dynamic State ◽  
State Monitoring ◽  
Initial Size ◽  
Fixed Amount ◽  
Safe Level

The life prediction is to estimate the life while the flaw initial size and critical size are knows. On the contrary, the life control is to estimate the flaw initial size at the predetermined life. Nondestructive test would be used to detect the flaws whose sizes are bigger than the allowable initial size estimated by the method, and corresponding repair or replacement of parts or components would insure the reliability and safety of structure in its lifetime. Aiming at this problem, the fixed amount relation between undetected probability of flaw of in service pressure vessel and the independence examination times is established in the base of examination results before. The ability of nondestructive testing is availably increased, the undetected probability of flaw of in service pressure vessel is controlled within the scope of an enough low and safe level. dynamic state monitor is realized.

scholarly journals Critical Review of Polymeric Building Envelope Materials: Degradation, Durability and Service Life Prediction

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 299
Author(s):  
Marzieh Riahinezhad ◽  
Madeleine Hallman ◽  
J-F. Masson
Keyword(s):  
Climate Change ◽  
Service Life ◽  
Critical Review ◽  
Life Prediction ◽  
Building Envelope ◽  
Service Life Prediction ◽  
Degradation Mechanisms ◽  
Material Component ◽  
Aging Conditions ◽  
Environmentally Sound

This paper provides a critical review of the degradation, durability and service life prediction (SLP) of polymeric building envelope materials (BEMs), namely, claddings, air/vapour barriers, insulations, sealants, gaskets and fenestration. The rate of material deterioration and properties determine the usefulness of a product; therefore, knowledge of the significant degradation mechanisms in play for BEMs is key to the design of proper SLP methods. SLP seeks to estimate the life expectancy of a material/component exposed to in-service conditions. This topic is especially important with respect to the potential impacts of climate change. The surrounding environment of a building dictates the degradation mechanisms in play, and as climate change progresses, material aging conditions become more unpredictable. This can result in unexpected changes and/or damages to BEMs, and shorter than expected SL. The development of more comprehensive SLP methods is economically and environmentally sound, and it will provide more confidence, comfort and safety to all building users. The goal of this paper is to review the existing literature in order to identify the knowledge gaps and provide suggestions to address these gaps in light of the rapidly evolving climate.

Gigacycle Fatigue of Welded Joints of Structural Materials (A Review)

2016 ◽  
Vol 17 ◽  
pp. 14-30 ◽  
Author(s):  
Okechukwu P. Nwachukwu ◽  
Alexander V. Gridasov ◽  
Ekaterina A. Gridasova
Keyword(s):  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Testing Machine ◽  
Structural Materials ◽  
Fatigue Tests ◽  
Material Defects ◽  
Graphite Cast Iron ◽  
Ultrasonic Fatigue ◽  
Materials Used ◽  
Fatigue Failures

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.

Machine for testing the strength of structural materials under cyclic torsion at high temperatures

1974 ◽  
Vol 6 (6) ◽  
pp. 746-748
Author(s):  
V. N. Rudenko ◽  
A. S. Spivakov ◽  
A. F. Bezverbnyi
Keyword(s):  
High Temperatures ◽  
Structural Materials ◽  
Cyclic Torsion

scholarly journals Development of a Self-Destroying Fuse for Rocket Propelled Grenade Munitions

2019 ◽  
Vol 49 (4) ◽  
pp. 521-532
Author(s):  
Rafał Bazela
Keyword(s):  
Field Testing ◽  
Structural Materials ◽  
Research Paper ◽  
High Quality ◽  
Short Summary ◽  
Materials Used ◽  
Technology Demonstrator

Abstract The paper presents a proposal for modernising the DCR-type self-destroying fuse for rocket propelled grenade munitions. It features a description of the fuse’s structure concept, its design and operation by presenting its particular stages. The further part is a description of the structural materials used for constructing the modernised fuse. Then, a conducted analysis of laboratory and field testing of the developed fuse models was presented. The results of the field testing of the devised and developed modernised fuse technology demonstrator are shown. The high quality of the fuse’s operation was demonstrated. The research paper is concluded with a short summary and a list of the literature used.

scholarly journals Design of experiments for verification of computational life prediction methods

2019 ◽  
Vol 18 (3) ◽  
pp. 143-154
Author(s):  
O. V. Samsonova ◽  
K. V. Fetisov ◽  
I. V. Karpman ◽  
I. V. Burtseva
Keyword(s):  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Turbine Engines ◽  
Prediction Methods ◽  
Gas Turbine Engines ◽  
Loading Conditions ◽  
Load History ◽  
Strain Behavior ◽  
Before And After ◽  
Two Stages

The failure of heavily loaded rotating parts of aviation gas turbine engines may bring about dangerous consequences. The life of such parts is limited with the use of computational and experimental methods. Computational life prediction methods that are used without carrying out life-cycle tests of engine parts or assemblies should be substantiated experimentally. The best option for verifying the computational methods is to use the results of cyclic tests of model disks. These tests make it possible to reproduce loading conditions and surface conditions that correspond to those of real disks, and the data on the load history and material properties make it possible to simulate stress-strain behavior of disks under test conditions by calculation. This paper shows the process of planning such tests. It is assumed that the tests will be carried out in two stages - before and after the initiation of a low-cycle fatigue crack. A number of criteria are formulated that the geometry of model disks and their loading conditions are to satisfy. Based on these criteria, model disks were designed and the conditions for their testing were selected.

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