Viscoplastic-dynamic crack propagation: Experimental and analysis research for crack arrest applications in engineering structures

1990 ◽  
Vol 42 (3) ◽  
pp. 239-260 ◽  
Author(s):  
M. F. Kanninen ◽  
S. J. Hudak ◽  
H. R. Couque ◽  
R. J. Dexter ◽  
P. E. O'Donoghue
Keyword(s):  
Crack Propagation ◽  
Crack Arrest ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Engineering Structures

Dynamic Crack Propagation in Precracked Cylindrical Vessels Subjected to Shock Loading

1981 ◽  
Vol 103 (2) ◽  
pp. 155-159 ◽  
Author(s):  
C. H. Popelar ◽  
P. C. Gehlen ◽  
M. F. Kanninen
Keyword(s):  
Crack Propagation ◽  
Shock Loading ◽  
Axial Direction ◽  
Crack Arrest ◽  
Dynamic Fracture Toughness ◽  
Impulsive Loading ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Initiation And Propagation ◽  
Growth Initiation

Previous work has shown that a speed-independent dynamic fracture toughness property can be used in an elastodynamic analysis to describe crack initiation and unstable propagation under impact loading. In this paper, a further step is taken by extending the analysis from simple laboratory test specimens to treat more realistic crack-structure geometries. A circular cylinder with an initial part-through wall crack subjected to an impulsive loading on its inner surface is considered. The crack is in a radial-axial plane and has its length in the axial direction long enough that a state of plane strain exists at the center of the crack. Crack growth initiation and propagation through the wall is then calculated. It is found that, once initiated, crack propagation will continue until the crack penetrates the wall. Crack arrest within the wall does not appear to be possible under the conditions considered in this paper.

Characteristics of dynamic crack propagation in a weak snowpack layer over its entire life cycle

2021 ◽  
Author(s):  
Bastian Bergfeld ◽  
Alec van Herwijnen ◽  
Gregoire Bobillier ◽  
Jürg Schweizer
Keyword(s):  
Life Cycle ◽  
Elastic Modulus ◽  
Crack Propagation ◽  
Effective Elastic Modulus ◽  
Crack Arrest ◽  
Image Correlation ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Displacement Fields ◽  
Weak Layer

<p>For a slab avalanche to release, a weak layer buried below a cohesive snow slab is required, and the system of weak layer and slab must support crack propagation over large distances. This process, called “dynamic crack propagation”, is highly relevant for avalanche release, and computational models are nowadays able to model crack propagation over increasingly larger scales. Field measurements on dynamic crack propagation are however very scarce, although these are required to validate models. We therefore performed a series of flat field PST experiments up to ten meters long over a period of 10 weeks. During this time, PST results evolved from crack arrest to full propagation and back to crack arrest – reflecting the life cycle of the weak layer. All PST experiments were analyzed using digital image correlation to derive high-resolution displacement fields to compute dynamic crack propagation metrics, including crack length and speed as well as touchdown distance, the distance from the crack tip to the trailing point where the slab comes into contact with the substratum. Comparing the displacement fields during sawing to a mechanical model, we estimated the effective elastic modulus of slab and weak layer as well as the specific fracture energy of the weak layer. Our results show how dynamic crack propagation characteristics change over the life cycle of a weak layer and how these measures relate to snowpack properties such as load and effective elastic modulus of the slab. We found that crack speed was highest for PSTs resulting in full propagation and that the touchdown length increased with increasing elastic modulus of the slab. Our dataset provides unique insight into the dynamics of crack propagation, and provides valuable data to validate models used to study sustained crack propagation.</p>

scholarly journals Rock Dynamic Crack Propagation under Different Loading Rates Using Improved Single Cleavage Semi-Circle Specimen

2019 ◽  
Vol 9 (22) ◽  
pp. 4944
Author(s):  
Fei Wang ◽  
Meng Wang ◽  
Mohaddeseh Mousavi Nezhad ◽  
Hao Qiu ◽  
Peng Ying ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Stress Intensity Factor ◽  
Crack Arrest ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Hopkinson Pressure Bar ◽  
Tight Sandstone ◽  
Crack Propagation Velocity ◽  
Loading Rates

The objective of this paper is to investigate the complete process of dynamic crack propagation in brittle materials under different loading rates. By using Improved Single Cleavage Semi-Circle (ISCSC) specimens and Split Hopkinson Pressure Bar equipment, experiments were conducted, with the fracture phenomenon and crack propagation of tight sandstone investigated. Meanwhile, the process of crack propagation behaviour was simulated. Moreover, with the experimental–numerical method, the crack propagation dynamic stress intensity factor (DSIF) was also calculated. Then, the crack propagation toughness of tight sandstone under different loading rates was investigated and illustrated elaborately. Investigation results demonstrate that ISCSC specimens can achieve the crack arrest position unchanged, and the numerical simulation could effectively deduce the actual crack propagation, as their results were well matched. During crack propagation, the crack propagation DSIF in the whole process increases with the rising loading rate, and so does the crack propagation velocity. Several significant dynamic material parameters of tight sandstone are also given, for engineering reference.

Dynamic crack propagation in matrix involving inclusions by a time-domain BEM

2012 ◽  
Vol 36 (5) ◽  
pp. 651-657 ◽  
Author(s):  
Jun Lei ◽  
Yue-Sheng Wang ◽  
Yifeng Huang ◽  
Qingsheng Yang ◽  
Chuanzeng Zhang
Keyword(s):  
Crack Propagation ◽  
Time Domain ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack
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