Effects of residual stress by EB welds on assessment of crack arrest temperature (CAT)

2020 ◽  
Vol 64 (7) ◽  
pp. 1161-1174
Author(s):  
Chiyomi Iwatake ◽  
Masahito Kaneko ◽  
Kazuyuki Matsumoto ◽  
Tsutomu Fukui ◽  
Shuji Aihara ◽  
...  
Keyword(s):  
Residual Stress ◽  
Crack Arrest ◽  
Arrest Temperature

The Crack Arrest Capability of 9-Percent Ni Steels (ASTM 553, Type 1) LNG Storage Tanks

1991 ◽  
Vol 113 (3) ◽  
pp. 380-384
Author(s):  
P. B. Crosley ◽  
E. J. Ripling
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
High Stress ◽  
Crack Arrest ◽  
Storage Tanks ◽  
Membrane Stress ◽  
High Stress Region ◽  
Fast Running ◽  
Stress Region

Safety of structures can be assured, even if cracks initiate in localized regions of abnormally low toughness, and/or abnormally high stress (LT/HS), if the materials from which they are fabricated have a high enough crack arrest fracture toughness. When this requirement is met, fast-running cracks that initiate in LT/HS regions arrest when their tip encounters material having normal toughness and stresses. The work described in this paper was carried out to determine the crack arrest capability of LNG storage tanks by determining the longest LT/HS region in which a crack could initiate and still arrest when it leaves this region. The determination consisted of relating a fracture analysis with the measured full-thickness crack arrest fracture toughness of three 9-percent Ni plates which were reported in reference [1]. The calculations used a residual stress pattern, produced by welding, superimposed on a typical membrane stress. The residual stress was selected as an example of a localized high stress region. It was found that tanks built from the poorest of the three tested plates could arrest cracks about 3/4 m long, while tanks built from the two tougher plates could arrest cracks almost 2 m long.

Crack arrest in Si3N4-based layered composites with residual stress

2004 ◽  
Vol 64 (13-14) ◽  
pp. 1947-1957 ◽  
Author(s):  
M. Lugovy ◽  
V. Slyunyayev ◽  
V. Subbotin ◽  
N. Orlovskaya ◽  
G. Gogotsi
Keyword(s):  
Residual Stress ◽  
Crack Arrest ◽  
Layered Composites

Characterization of Strain Hardening Behavior and Residual Stress Induction Used For Crack Arrest in a Biocompatible Material

2009 ◽  
Vol 1242 ◽  
Author(s):  
G. Urriolagoitia-Sosa ◽  
A. Molina-Ballinas ◽  
G. Urriolagoitia-Calderón ◽  
L. H. Hernández-Gómez ◽  
y J. M. Sandoval-Pineda
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Stress Field ◽  
Strain Hardening ◽  
Structural Integrity ◽  
Crack Arrest ◽  
Mechanical Resistance ◽  
Residual Stress Field ◽  
Strain Hardening Behavior

ABSTRACTFor centuries, the manipulation of mechanical properties for the development of components has been extremely important. Its relevance is based on improving the service life in the components. The aim of some techniques that have been used is to introduce strain hardening (tensile) and a beneficial residual stress field. Nevertheless, the application of both methods is very common when the component is manufactured, but the lack of knowledge of the final physical state of the material could compromise the structural integrity of the final product. This work presents a numerical evaluation concerning the characterization of a stainless steel AISI 316L, having a homogeneous axial history and a residual stress field. The relevance of the work is focused in a new methodology that can be used to improve the mechanical resistance of the component and to arrest crack propagation. By altering the mechanical properties of the material, it could be possible to delay nucleation and interrupt the propagation of cracks. This study also shows that if the strain hardening behaviour and the introduction of the residual stress field is not done properly, it could result in a component susceptible to fail. In the same sense, bending tests are proposed to provide tensile and compressive stress profiles.

Damage Extension in Carbon Fiber/PEEK Crossply Laminates under Low Velocity Impact

1994 ◽  
Vol 28 (8) ◽  
pp. 684-707 ◽  
Author(s):  
H. Wang ◽  
T. Vu-Khanh
Keyword(s):  
Residual Stress ◽  
Carbon Fiber ◽  
Transverse Crack ◽  
Crack Arrest ◽  
Low Velocity Impact ◽  
Mode Ii ◽  
Unstable Fracture ◽  
Low Velocity ◽  
Velocity Impact ◽  
Arrest Toughness

Low-velocity impact in carbon fiber/PEEK crossply laminates has been studied by test and analysis. Emphases of the study were focused on the material properties which may control the damage extension of transverse crack and delamination. It was found that, considering the thermal residual stress and the crack constraining effect, extension of transverse cracks could not be predicted by the Strength of Materials approach. The impact-induced delamination could be characterized by the crack arrest concept of fracture mechanics. The delamination resulted from a Mode II-dominated unstable fracture, which occurred under displacement-controlled conditions and seemed to be arrested at a constant interlaminar fracture energy. It was found that the thermoplastic APC-2 composite exhibits the same damage modes as epoxy composites under low velocity impact. Both the matrix-controlled damage and the fiber-controlled penetration may become the dominant failure mode, depending on the stacking sequence of the laminate. The residual stress in the thermoplastic laminates is as high as half of the transverse strength of the unidirectional material. The crack constraining effect tends to increase the in situ transverse strength of the lamina as the lamina thickness decreases. Considering the residual stress and crack constraining effect, the transverse crack extension cannot be predicted by the Strength of Materials approach. The crack arrest concept of fracture mechanics seems to be a useful approach to predict the extension of impact-induced delamination. The delamination resulted from a Mode II-dominated unstable fracture, which occurred under displacement-controlled conditions and seemed to be arrested at a constant interlaminar fracture energy. By assuming the delamination arrest at about the time of maximum impact load, the delamination arrest toughness could be evaluated from the test data of [05/905/05] laminates. The delamination arrest toughness is also found to be close to the Mode II-propagation toughness of the material.

Assessment of Steels for Nuclear Reactor Pressure Vessels

1964 ◽  
Vol 86 (4) ◽  
pp. 393-401 ◽  
Author(s):  
A. Cowan ◽  
R. W. Nichols
Keyword(s):  
Large Body ◽  
Stress Rupture ◽  
Crack Arrest ◽  
Pressure Vessels ◽  
Small Scale ◽  
Specimen Thickness ◽  
Stress Concentrations ◽  
Flat Plates ◽  
Reactor Pressure ◽  
Arrest Temperature

Some of the materials problems associated with the use of mild steels in large gas-cooled reactor pressure vessels are discussed. Tests to failure of 5-ft-dia 0.36 percent carbon-steel vessels with through-thickness longitudinal slots, supported by tests on 7-ft-wide centrally slotted flat plates, have indicated that rapid failure at working-stress levels can only initiate from very long cracks, feet rather than inches in length. Of the mechanisms whereby realistic defects can grow to these sizes, brittle-crack propagation is considered the most important and this can be prevented by the maintenance of a minimum pressurization temperature, based on the crack-arrest temperature. The tests used to assess the crack arrest temperature of plates up to 4 in. thick are described; compared with tests on thinner specimens the thick plate gives arrest temperatures higher by approximately 10 deg C per in. of test-specimen thickness. A comparison is made of crack-arrest temperature and data given by small-scale tests, particularly the Charpy V-notch test. Mechanical limitations of creep deformation in some current designs have been more restrictive on design stress than the values allowed by the existing BS.1500. The test data quoted for stress-rupture and fatigue indicate that these modes of crack extension are not important in current designs. Possible magnitudes and effects of stress concentrations are quoted but, other than a large body of satisfactory service operation, there is little direct evidence of the effect of operating in the creep range on these stress concentrations. The importance of work of this type in justifying higher design stresses and more economic use of material is emphasized.

Mechanics of fracture in large structures

1965 ◽  
Vol 285 (1400) ◽  
pp. 10-21 ◽  
Keyword(s):  
Size Effects ◽  
Unstable Mode ◽  
Crack Arrest ◽  
Tensile Fracture ◽  
Unstable Fracture ◽  
Dislocation Theory ◽  
Physical Conditions ◽  
Large Structures ◽  
Deformation And Fracture ◽  
Arrest Temperature

A dislocation theory of cracks, which takes account of elastic-plastic and other non-linear modes of deformation, is used to discuss the geometrical and physical conditions for unstable fracture. The importance of discontinuous cracking in providing an unstable mode of plane strain, semi-brittle, tensile fracture is emphasized. The general formulae reduce to those of Griffith, Orowan, and Irwin, at low stresses. Size effects and their relation to microscopic processes of deformation and fracture, especially twinning, are discussed and the concept of the crack arrest temperature is considered.

Crack arrest in thin metallic film stacks due to material- and residual stress inhomogeneities

2018 ◽  
Vol 668 ◽  
pp. 14-22 ◽  
Author(s):  
D. Kozic ◽  
H.-P. Gänser ◽  
R. Brunner ◽  
D. Kiener ◽  
T. Antretter ◽  
...  
Keyword(s):  
Residual Stress ◽  
Crack Arrest ◽  
Metallic Film ◽  
Thin Metallic Film
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