Crack initiation and early propagation plane orientation of 2A12-T4 aluminum alloy under tension-torsion fatigue loading including mean tensile stress

From the perspective of damage mechanics, the damage parameters were introduced as the characterizing quantity of the decrease in the mechanical properties of powder superalloy material FGH96 under fatigue loading. By deriving a damage evolution equation, a fatigue life prediction model of powder superalloy containing inclusions was constructed based on damage mechanics. The specimens containing elliptical subsurface inclusions and semielliptical surface inclusions were considered. The CONTA172 and TARGE169 elements of finite element software (ANSYS) were used to simulate the interfacial debonding between the inclusions and matrix, and the interface crack initiation life was calculated. Through finite element modeling, the stress field evolution during the interface debonding was traced by simulation. Finally, the effect of the position and shape size of inclusions on interface debonding was explored.

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Evaluation of Transverse Crack Initiation in Cross-Ply CFRP Laminates under Fatigue Loading

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A ◽

10.1299/kikaia.77.1123 ◽

2011 ◽

Vol 77 (779) ◽

pp. 1123-1134 ◽

Cited By ~ 3

Author(s):

Keigo TAKAMURA ◽

Atsushi HOSOI ◽

Narumichi SATO ◽

Hiroyuki KAWADA

Keyword(s):

Crack Initiation ◽

Transverse Crack ◽

Fatigue Loading ◽

Cfrp Laminates

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Effect of Material Property and Hole Cold Expansion Rate on Fatigue Crack Initiation and Propagation on 2024-T351 Aluminum Alloy Holes

10.1115/1.0004486v ◽

2021 ◽

Author(s):

Subrato Roy ◽

Dave Kim

Keyword(s):

Aluminum Alloy ◽

Fatigue Crack ◽

Crack Initiation ◽

Material Property ◽

Fatigue Crack Initiation ◽

Expansion Rate ◽

Crack Initiation And Propagation ◽

Cold Expansion ◽

Initiation And Propagation

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Fatigue crack paths and properties in A356-T6 aluminum alloy microstructurally modified by friction stir processing under different conditions

Frattura ed Integrità Strutturale ◽

10.3221/igf-esis.34.38 ◽

2015 ◽

Author(s):

A. Tajiri ◽

Y. Uematsu ◽

T. Kakiuchi ◽

Y. Suzuki

Keyword(s):

Aluminum Alloy ◽

Fatigue Crack ◽

Crack Initiation ◽

Friction Stir Processing ◽

Casting Defects ◽

Processing Conditions ◽

Tool Rotational Speed ◽

Crack Initiation And Propagation ◽

Friction Stir ◽

Initiation And Propagation

A356-T6 cast aluminum alloy is a light weight structural material, but fatigue crack initiates and propagates from a casting defect leading to final fracture. Thus it is important to eliminate casting defects. In this study, friction stir processing (FSP) was applied to A356-T6, in which rotating tool with probe and shoulder was plunged into the material and travels along the longitudinal direction to induce severe plastic deformation, resulting in the modification of microstructure. Two different processing conditions with low and high tool rotational speeds were tried and subsequently fully reversed fatigue tests were performed to investigate the effect of processing conditions on the crack initiation and propagation behavior. The fatigue strengths were successfully improved by both conditions due to the elimination of casting defects. But the lower tool rotational speed could further improve fatigue strength than the higher speed. EBSD analyses revealed that the higher tool rotational speed resulted in the severer texture having detrimental effects on fatigue crack initiation and propagation resistances.

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A DIC-Based Study on Fatigue Damage Evolution in Pre-Corroded Aluminum Alloy 2024-T4

Materials ◽

10.3390/ma11112243 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2243 ◽

Cited By ~ 1

Author(s):

Haipeng Song ◽

Changchun Liu ◽

Hao Zhang ◽

Sean Leen

Keyword(s):

Aluminum Alloy ◽

Fatigue Crack ◽

Crack Initiation ◽

Fatigue Damage ◽

Damage Evolution ◽

Image Correlation ◽

Multiple Cracks ◽

Mixed Mode Fracture ◽

Corrosion Condition ◽

Aluminum Alloy 2024

This paper investigates the fatigue damage and cracking behavior of aluminum alloy 2024-T4 with different levels of prior corrosion. Damage evolution, crack initiation and propagation were experimentally analyzed by digital image correlation, scanning electron microscopy and damage curves. Prior corrosion is shown to cause accelerated damage accumulation, inducing premature fatigue crack initiation, and affecting crack nucleation location, crack orientation and fracture path. For the pre-corrosion condition, although multiple cracks were observed, only one corrosion-initiated primary crack dominates the failure process, in contrast to the plain fatigue cases, where multiple cracks propagated simultaneously leading to final coalescence and fracture. Based on the experimental observations, a mixed-mode fracture model is proposed and shown to successfully predict fatigue crack growth and failure from the single dominant localized corrosion region.

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600 mm-Wide Strip Casting Using Single Roll Caster Equipped with Scraper

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.805.43 ◽

2019 ◽

Vol 805 ◽

pp. 43-49

Author(s):

Toshio Haga

Keyword(s):

Mechanical Properties ◽

Aluminum Alloy ◽

Tensile Stress ◽

Tension Test ◽

Alloy Strip ◽

Full Width ◽

Striped Pattern ◽

Wide Strip ◽

Twin Roll Caster ◽

Twin Roll

The casting of a 600 mm-wide 5182 aluminum alloy strip was attempted using a single-roll caster equipped with a scraper. This caster could cast a strip at speeds ranging from 10 to 40 m/min. These casting speeds are much higher than that of a conventional twin-roll caster. The scraper load suitable for scribing the wide strip was investigated. The strip could be scribed at full width by the scraper. The mechanical properties of the strip were investigated using a tension test and a cup test. The tensile stress was 320 MPa and the elongation was 30%. When deep drawing was conducted, no striped pattern, which occurs via segregation, appeared when both surfaces were facing outside.

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SEM In Situ Investigation on Fatigue Cracking Behavior of X80 Pipeline Steel with Inclusions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.284-286.1096 ◽

2011 ◽

Vol 284-286 ◽

pp. 1096-1100 ◽

Cited By ~ 1

Author(s):

Ke Tong ◽

Yan Ping Zeng ◽

Xin Li Han ◽

Yao Rong Feng ◽

Xiao Dong He

Keyword(s):

Crack Initiation ◽

Pipeline Steel ◽

Fatigue Cracking ◽

Fatigue Loading ◽

In Situ Observation ◽

X80 Pipeline Steel ◽

Cracking Behavior ◽

The Matrix ◽

Extension Period

The micro-mechanical behavior of inclusions in X80 pipeline steel under fatigue loading was investigated by means of SEM in situ observation. The influence of sizes and shapes of inclusion on crack initiation and propagation was analyzed. The result shows that for large-size single-particle inclusion, cracks initiate from the interior under the fatigue loading. When a certain circulation cycles are reached, cracks initiate at the matrix near the sharp corner of the inclusion. The cracks extend at the matrix during the stable extension period and unstable extension period following the crack initiation, until fracture occurred. For chain inclusion, cracks first initiate at the interface between inclusion and matrix within the chain area, and the circulation cycles needed for initiation are far less than single inclusion. Cracks steadily extend after the initiation, and then fracture after very short circulation cycles. A chain of inclusion with the shape corners is serious harmful to the fatigue properties.

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Study on Crack Initiation and Propagation of New Corrosion Inhibitor during Stress Corrosion of Aluminum Alloy

Journal of Spectroscopy ◽

10.1155/2020/4508512 ◽

2020 ◽

Vol 2020 ◽

pp. 1-18

Author(s):

Juan Du ◽

Zi-ming Wei ◽

Xu-dong Yang ◽

Qing-mao Liu ◽

Hai-peng Song ◽

...

Keyword(s):

Aluminum Alloy ◽

Crack Initiation ◽

Corrosion Inhibitor ◽

Electrochemical Impedance ◽

Sodium Succinate ◽

Sodium Dodecyl ◽

Sodium Dodecyl Benzene Sulfonate ◽

Inhibition Mechanism ◽

Crack Initiation And Propagation ◽

Initiation And Propagation

In this paper, a novel method combining electrochemical impedance spectroscopy (EIS) and phase shift was used to systematically study the effect of corrosion inhibitor (sodium succinate, sodium dodecyl benzene sulfonate, and new corrosion inhibitor, namely, bis [2-amino-3-(dodecyl dimethyl quaternary ammonium) propyl]-propylamine dichloro) on crack initiation and propagation of aluminum alloy during the slow strain rate tensile process. Using a variety of characterization methods to verify the feasibility of using the new method for in-situ prediction, Kramers–Kronig transformations have been used to validate the experimental data obtained with the EIS measurements. The corrosion inhibition mechanism of these three kinds of inhibitors in the SSRT process was analyzed.

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Energy Dissipation Measurement in Improved Spatial Resolution Under Fatigue Loading

Experimental Mechanics ◽

10.1007/s11340-019-00552-w ◽

2019 ◽

Vol 60 (2) ◽

pp. 181-189

Author(s):

A. Akai ◽

D. Shiozawa ◽

T. Yamada ◽

T. Sakagami

Keyword(s):

Fatigue Crack ◽

Energy Dissipation ◽

Crack Initiation ◽

Fatigue Limit ◽

Spatial Resolution ◽

Fatigue Crack Initiation ◽

Fatigue Loading ◽

Dissipated Energy ◽

Damage Initiation ◽

Slip Bands

Abstract Recently, a technique for rapidly determining a material’s fatigue limit by measuring energy dissipation using infrared thermography has received increasing interest. Measuring the energy dissipation of a material under fatigue loading allows the rapid determination of a stress level that empirically coincides with its fatigue limit. To clarify the physical implications of the rapid fatigue limit determination, the relationship between energy dissipation and fatigue damage initiation process was investigated. To discuss the fatigue damage initiation process at grain size scale, we performed high-spatial-resolution dissipated energy measurements on type 316L austenitic stainless steel, and observed the slip bands on the same side of the specimen. The preprocessing of dissipated energy measurement such as motion compensation and a smoothing filter was applied. It was found that the distribution of dissipated energy obtained by improved spatial resolution measurement pinpointed the location of fatigue crack initiation. Owing to the positive correlation between the magnitude of dissipated energy and number of slip bands, it was suggested that the dissipated energy was associated with the behavior of slip bands, with regions of high dissipated energy predicting the location of fatigue crack initiation.

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Calculating crack initiation directions for in-phase biaxial fatigue loading

International Journal of Fatigue ◽

10.1016/j.ijfatigue.2013.03.011 ◽

2014 ◽

Vol 58 ◽

pp. 166-171 ◽

Cited By ~ 9

Author(s):

V. Chaves ◽

A. Navarro ◽

C. Madrigal ◽

C. Vallellano

Keyword(s):

Crack Initiation ◽

Fatigue Loading ◽

Biaxial Fatigue

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