Stress Redistribution and Rupture Due to Creep in a Uniformly Stretched Thin Plate Containing a Circular Hole

1973 ◽  
Vol 40 (1) ◽  
pp. 244-250 ◽  
Author(s):  
D. R. Hayhurst
Keyword(s):  
Elevated Temperatures ◽  
Numerical Procedure ◽  
Prediction Method ◽  
Creep Rupture ◽  
Constitutive Relationship ◽  
High Temperature Creep ◽  
Uniaxial Creep ◽  
Aluminum Plates ◽  
Single Stress ◽  
Rupture Behavior

A uniaxial theory of low-stress, high-temperature creep rupture has been shown to predict the results of uniaxial creep rupture tests. By including the creep rupture relationships into the accepted multiaxial deformation laws and following the numerical procedure outlined in a previous publication, a lower bound on the rupture time has been obtained for the case of a biaxially loaded plate containing a small hole at its center. It has been shown that the rupture behavior of the structure is controlled by a single stress whose magnitude is independent of the form of the constitutive relationship. The results of the prediction method agreed well with the experimentally determined values for aluminum plates tested at elevated temperatures.

scholarly journals Creep rupture properties of bare and coated polycrystalline nickel-based superalloy Rene®80

2021 ◽  
pp. 36-36
Author(s):  
M.M. Barjesteh ◽  
S.M. Abbasi ◽  
K.Z. Madar ◽  
K. Shirvani
Keyword(s):  
Elevated Temperatures ◽  
Life Time ◽  
Creep Rupture ◽  
Polycrystalline Nickel ◽  
Creep Life ◽  
Nickel Based Superalloy ◽  
Platinum Aluminide ◽  
Rupture Properties ◽  
Low Activity ◽  
Rupture Behavior

Creep deformation is one of the life time limiting reasons for gas turbine parts that are subjected to stresses at elevated temperatures. In this study, creep rupture behavior of uncoated and platinum-aluminide coated Rene?80 has been determined at 760?C/657 MPa, 871?C/343 MPa and 982?C/190 Mpa in air. For this purpose, an initial layer of platinum with a thickness of 6?m was applied on the creep specimens. Subsequently, the aluminizing were formed in the conventional pack cementation method via the Low Temperature-High Activity (LTHA) and High Temperature-Low Activity (HTLA) processes. Results of creep-rupture tests showed a decrease in resistance to creep rupture of coated specimen, compared to the uncoated ones. The reductions in rupture lives in LTHA and HTLA methods at 760?C/657 MPa, 871?C/343 MPa and 982?C/190 MPa were almost (26% and 41.8%), (27.6% and 38.5%) and (22.4% and 40.3%), respectively as compared to the uncoated ones. However, the HTLA aluminizing method showed an intense reduction in creep life. Results of fractographic studies on coated and uncoated specimens indicated a combination of ductile and brittle failure mechanisms for all samples. Although, the base failure mode in substrate was grain boundary voids, cracks initiated from coating at 760?C/657MPa and 871?C/343. No cracking in the coating was observed at 982?C/190MPa.

The Effect of Stress Concentrations on the Creep Rupture of Tension Panels

1975 ◽  
Vol 42 (3) ◽  
pp. 613-618 ◽  
Author(s):  
D. R. Hayhurst ◽  
C. J. Morrison ◽  
F. A. Leckie
Keyword(s):  
Steady State ◽  
High Temperatures ◽  
Lower Bounds ◽  
Plane Stress ◽  
Rupture Life ◽  
Creep Rupture ◽  
Stress Concentrations ◽  
Engineering Structures ◽  
Aluminum Plates ◽  
Rupture Behavior

The creep rupture behavior of metals at high temperatures is reviewed for constant homogeneous states of multiaxial stress. Currently used methods for estimating the creep rupture life of engineering structures are discussed. The rupture lives of plane stress tension plates containing discontinuities are predicted by the different methods. The estimates of life are compared with the results of experiments carried out on copper and aluminum plates. It is shown that the magnitudes of the elastic and steady-state stresses do not influence the rupture behavior of the tension plates examined. The redistribution of stress in the structures which occurs due to tertiary creep plays an important part in determining the rupture lives. A method of predicting lower bounds on the structural rupture lives is presented and shown to closely predict the results of experiments.

Microstructure Evolution and Creep Rupture Behavior of Modified 9Cr-1Mo Steel Welded Joint

2020 ◽  
Author(s):  
Facai Ren ◽  
Xiaoying Tang ◽  
Jinsha Xu ◽  
Jun Si ◽  
Yiwen Yuan
Keyword(s):  
Electron Microscope ◽  
Microstructure Evolution ◽  
Welded Joint ◽  
Rupture Life ◽  
Optical Microscope ◽  
Creep Rupture ◽  
Creep Tests ◽  
Uniaxial Creep ◽  
Before And After ◽  
Rupture Behavior

Abstract Microstructure evolution and creep rupture behavior of modified 9Cr-1Mo steel welded joint used for steam cooler in high pressure heater system were systematically studied in this paper. Creep tests were carried out using uniaxial creep specimens machined from the normalized and tempered plate at 818K and 838K with the stresses ranging from 150 to 225MPa. The curve of stress vs. rupture time was achieved to evaluate the creep rupture life of modified 9Cr-1Mo steel welded joint. The creep data were analyzed in terms of Norton’s power law, Monkman-Grant relation and modified Monkman-Grant relation. Microstructure before and after creep exposure were analyzed by optical microscope, scanning electron microscope and transmission electron microscope, to further explain the rupture mechanisms of modified 9Cr-1Mo steel welded joint.

Creep-rupture behavior of iridium at elevated temperatures

1975 ◽  
Vol 6 (4) ◽  
pp. 885-889 ◽  
Author(s):  
R. L. Mehan ◽  
E. C. Duderstadt ◽  
E. H. Sayell
Keyword(s):  
Elevated Temperatures ◽  
Creep Rupture ◽  
Rupture Behavior

DOWMETAL HZ32XA

Alloy Digest ◽  
1956 ◽  
Vol 5 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Creep Resistance ◽  
Zirconium Alloy ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
High Temperature Creep ◽  
Aged Condition ◽  
Chemical Company ◽  
Temperature Performance

Abstract DOWMETAL HZ32XA is a magnesium-thorium-zinc-zirconium alloy having good high temperature creep resistance, and is recommended for applications at elevated temperatures. It is used in the artificially aged condition (T5). This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as heat treating, machining, and joining. Filing Code: Mg-26. Producer or source: The Dow Chemical Company.

Development of continuum damage in the creep rupture of notched bars

1984 ◽  
Vol 311 (1516) ◽  
pp. 103-129 ◽  
Keyword(s):  
New York ◽  
Damage Mechanics ◽  
Axial Stress ◽  
Numerical Procedure ◽  
Creep Damage ◽  
Continuum Damage Mechanics ◽  
Constant Load ◽  
Creep Rupture ◽  
Continuum Damage ◽  
Discrete Crack

The creep rupture of circumferentially notched, circular tension bars which are subjected to constant load for long periods at constant temperature is studied both experimentally and by using a time-iterative numerical procedure which describes the formation and growth of creep damage as a field quantity. The procedure models the development of failed or cracked regions of material due to the growth and linkage of grain boundary defects. Close agreement is shown between experimental and theoretical values of the representative rupture stress, of the zones of creep damage and of the development of cracks for circular (Bridgman, Studies in large plastic flow and fracture , New York: McGraw-Hill (1952)) and British Standard notched specimens (B.S. no. 3500 (1969)). The minimum section of the circular notch is shown to be subjected to relatively uniform states of multi-axial stress and damage while the B.S. notch is shown to be subjected to non-uniform stress and damage fields in which single cracks grow through relatively undamaged material. The latter situation is shown to be analogous to the growth of a discrete crack in a lightly damaged continuum. The continuum damage mechanics theory presented here is shown to be capable of accurately predicting these extreme types of behaviour.

Sign in / Sign up

Export Citation Format

Share Document