scholarly journals Comparison of Fracture Response of Preflawed Tubes Under Internal Static and Detonation Loading

2003 ◽  
Author(s):  
Tong Wa Chao ◽  
Joseph E. Shepherd
Keyword(s):  
Crack Detection ◽  
Strain History ◽  
Strain Gages ◽  
Pressure Transducers ◽  
Gaseous Detonations ◽  
Propagation Behavior ◽  
Significant Difference ◽  
Detonation Loading ◽  
Crack Propagation Behavior ◽  
Axial Surface

Fracture experiments were performed on thin-walled and preflawed aluminum 6061-T6 tubes. Flaws were machined as external axial surface notches. The tubes were 1) statically loaded with oil, 2) statically loaded with nitrogen, and 3) dynamically loaded with gaseous detonations traveling at 2.4 km/s. The experiments were controlled so that comparisons could be made on sets of specimens with the same material, tube and flaw geometry, nominal loading amplitude, and flange supports, with the only difference being the dynamics of the loading. It was found that there is a significant difference in crack propagation behavior for the three types of loading. In this paper, fracture behavior will be discussed along with the fluid dynamics involved. The tubes were also instrumented with pressure transducers, crack detection gages, and strain gages so that data on loading, crack propagating speeds, and strain history can be compared.

scholarly journals Comparison of Fracture Response of Preflawed Tubes Under Internal Static and Detonation Loading

2004 ◽  
Vol 126 (3) ◽  
pp. 345-353 ◽  
Author(s):  
Tong Wa Chao ◽  
Joseph E. Shepherd
Keyword(s):  
Fracture Behavior ◽  
Crack Detection ◽  
Loading Rate ◽  
Accident Analysis ◽  
Strain Gages ◽  
Pressure Transducers ◽  
Gaseous Detonations ◽  
Fluid Properties ◽  
Detonation Loading

The role of loading rate and fluid properties in the fracture of piping under internal explosions is an important issue for designers and accident analysis. This was examined by fracture experiments on thin-walled and preflawed aluminum 6061-T6 tubes. The tubes were (1) statically loaded with oil, (2) statically loaded with nitrogen, and (3) dynamically loaded with gaseous detonations traveling at 2.4 km/s. The tubes were also instrumented with pressure transducers, crack detection gages, and strain gages. The experiments were controlled so that comparisons could be made on identical specimens. Fracture behavior was discussed along with fluid dynamics.

scholarly journals Unique Slow Crack Growth Behavior of Isotactic Polypropylene: The Role of Shear Layer-Spherulites Layer Alternated Structure

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2746
Author(s):  
Mingjin Liu ◽  
Jiaxu Luo ◽  
Jin Chen ◽  
Xueqin Gao ◽  
Qiang Fu ◽  
...  
Keyword(s):  
Shear Layer ◽  
Crack Growth ◽  
Isotactic Polypropylene ◽  
Slow Crack Growth ◽  
Crack Growth Behavior ◽  
Polymer Science ◽  
The Past ◽  
Propagation Behavior ◽  
Crack Propagation Behavior

With the development of polymer science, more attention is being paid to the longevity of polymer products. Slow crack growth (SCG), one of the most important factors that reveal the service life of the products, has been investigated widely in the past decades. Here, we manufactured an isotactic polypropylene (iPP) sample with a novel shear layer–spherulites layer alternated structure using multiflow vibration injection molding (MFVIM). However, the effect of the alternated structure on the SCG behavior has never been reported before. Surprisingly, the results showed that the resistivity of polymer to SCG can be enhanced remarkably due to the special alternated structure. Moreover, this sample shows unique slow crack propagation behavior in contrast to the sample with the same thickness of shear layer, presenting multiple microcracks in the spherulites layer, which can explain the reason of the resistivity improvement of polymer to SCG.

scholarly journals Crack Propagation Behavior of a Ni-Based Single-Crystal Superalloy during In Situ SEM Tensile Test at 1000 °C

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1047
Author(s):  
Wenxiang Jiang ◽  
Xiaoyi Ren ◽  
Jinghao Zhao ◽  
Jianli Zhou ◽  
Jinyao Ma ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Tensile Test ◽  
Single Crystal ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Single Crystal Superalloy ◽  
Propagation Path ◽  
Propagation Behavior ◽  
Crack Propagation Behavior

An in situ scanning electron microscope (SEM) tensile test for Ni-based single-crystal superalloy was carried out at 1000 °C. The stress displacement was obtained, and the yield strength and tensile strength of the superalloy were 699 MPa and 826 MPa, respectively. The crack propagation process, consisting of Model I crack and crystallographic shearing crack, was determined. More interestingly, the crack propagation path and rate affected by eutectics was directly observed and counted. Results show that the coalescence of the primary crack and second microcrack at the interface of a γ/γ′ matrix and eutectics would make the crack propagation rate increase from 0.3 μm/s to 0.4 μm/s. On the other hand, crack deflection decreased the rate to 0.05 μm/s. Moreover, movement of dislocations in front of the crack was also analyzed to explain the different crack propagation behavior in the superalloy.

Crack propagation behavior of inhomogeneous laminated Ti−Nb metal−metal composite

2019 ◽  
Vol 29 (9) ◽  
pp. 1882-1888 ◽  
Author(s):  
Wen-juan CHENG ◽  
Yong LIU ◽  
Da-peng ZHAO ◽  
Bin LIU ◽  
Yan-ni TAN ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Metal Composite ◽  
Propagation Behavior ◽  
Metal Metal ◽  
Crack Propagation Behavior

Analysis of Crack Propagation Behavior in Alumina with Different Grain Sizes under Static and Cyclic Fatigue

2004 ◽  
Vol 264-268 ◽  
pp. 793-796
Author(s):  
Hassan El Attaoui ◽  
Malika Saâdaoui ◽  
Jérôme Chevalier ◽  
Gilbert Fantozzi
Keyword(s):  
Crack Propagation ◽  
Cyclic Fatigue ◽  
Grain Sizes ◽  
Propagation Behavior ◽  
Crack Propagation Behavior
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