Creep damage and crack initiation behaviour of nickel-base single crystalline superalloys compact tension specimen with a void ahead of crack tip

2009 ◽  
Vol 510-511 ◽  
pp. 284-288 ◽  
Author(s):  
Z.X. Wen ◽  
N.X. Hou ◽  
Z.F. Yue
Keyword(s):  
Crack Initiation ◽  
Crack Tip ◽  
Creep Damage ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Tension Specimen ◽  
Single Crystalline ◽  
Nickel Base

Creep Behaviors of Nickel-Based Single Crystal Superalloys Compact Tension Specimen at High Temperature

2010 ◽  
Vol 146-147 ◽  
pp. 1322-1326 ◽  
Author(s):  
Zhi Xun Wen ◽  
Nai Xian Hou ◽  
Zhu Feng Yue
Keyword(s):  
Single Crystal ◽  
Crack Growth ◽  
Crack Tip ◽  
Creep Damage ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Crack Plane ◽  
Tension Specimen ◽  
Damage Constitutive Model ◽  
Crack Growth Path

Based on the microstructure change and damage characteristics of single crystal, a two-state-variable crystallographic creep damage constitutive model has been developed to investigate crack growth behaviors of single crystal compact tension specimen at 760 for two crack orientations: (001)[100] and (011)[100]. Numerical simulation results show the crack-tip stress fields are dependent on crack crystallographic orientation. Observations performed on the real single crystal specimens reveals that the macroscopic crack growth path appears as zigzag wave. The creep deformation at crack tip takes place in specific slip plane, and the deflection angles of crack initiation direction from the crack plane are 45º or 135 º and 53.7ºor 127.3º in the crack orientations (001)[100] and (011)[100]. A good agreement between experimental observations and numerical results is found.

Comparison of J-Integral Values and J-R Curves Between Carbon Steel Compact Tension Specimen and Pipe Specimen

2004 ◽  
Author(s):  
Masahiro Takanashi ◽  
Satoshi Izumi ◽  
Shinsuke Sakai ◽  
Naoki Miura
Keyword(s):  
Fracture Toughness ◽  
Carbon Steel ◽  
Crack Initiation ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Small Scale ◽  
Outer Diameter ◽  
J Integral ◽  
Tension Specimen ◽  
Elastic Plastic

In the present study, the transferability of elastic-plastic fracture toughness from a small-scale to a large-scale specimen was experimentally confirmed for carbon steel pipe with mild toughness. Fracture toughness tests were carried out on a pipe specimen 318.5 mm in outer diameter, 10.3 mm in thickness and having a through-wall crack, and also on a compact tension specimen 9.7mm in thickness, 25.4 mm in width, that had been cut out from the pipe specimen. Test results indicated the J-integral value of the pipe specimen at the crack initiation to be nearly twice that of the CT specimen. Finite element analysis conducted on the two specimens indicated this difference to arise primarily from the constraint near the crack front. Discussion was also made of the effects of crack orientation on elastic-plastic fracture toughness of CT specimens. The J-integral value at crack initiation in the specimen whose crack direction coincided with the pipe axial was found to be almost 54 % more than for specimens whose crack direction was circumferential.

An elastic-plastic finite element analysis of a compact tension specimen

1983 ◽  
Vol 18 (1) ◽  
pp. 69-75 ◽  
Author(s):  
A P Kfouri
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Crack Tip ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Tension Specimen ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Release Technique ◽  
Crack Tip Opening

Results from an elastic-plastic finite element analysis of a compact tension specimen (CTS) are presented and provide information on the growth of crack tip plastic zones, crack tip opening displacements, stresses and strains in the region of the crack tip, and Rice's J integral. The elastic-plastic crack separation energy rate GΔ is also evaluated when the crack extends at various loads by applying a crack tip node release technique.

scholarly journals Study on Stress Distribution Near Crack Tip in Beryllium Compact Tension Specimen

2010 ◽  
Vol 654-656 ◽  
pp. 2487-2490
Author(s):  
Ping Dong ◽  
Rui Wen Li ◽  
Sheng He Li
Keyword(s):  
Stress Distribution ◽  
Plastic Strain ◽  
Plastic Zone ◽  
Crack Tip ◽  
Element Model ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Stress And Strain ◽  
Tension Specimen ◽  
Critical Tension

In order to evaluate the fracture characteristic near the crack tip of beryllium specimen, beryllium compact tension specimen with plane strain state is designed. The stress distribution near the crack tip is measured at different loading level by X3000 stress analyzer. Moreover, a finite element model for calculated the stress and strain fields in beryllium compact tension specimen has also been set up. As a result, the stress and strain distribution near the crack tip at different loading has been calculated by this model. According to the critical tension loading of beryllium specimen, the maximum plastic strain and the radius of the plastic zone near the crack tip are determined, where the maximum plastic strain near the crack tip is about 0.018 and the maximum radius of plastic zone is about 0.3mm. Altogether, the fracture toughness of beryllium is obtained, which is about 19.1MPam1/2.

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