scholarly journals Dynamic Crack Propagation Using a Combined Molecular Dynamics/Extended Finite Element Approach

2010 ◽  
Vol 8 (2) ◽  
pp. 221-235 ◽  
Author(s):  
Pascal Aubertin ◽  
Julien Rethore ◽  
Rene de Borst
Keyword(s):  
Molecular Dynamics ◽  
Finite Element ◽  
Crack Propagation ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Extended Finite Element ◽  
Finite Element Approach ◽  
Element Approach

scholarly journals A molecular dynamics/extended finite element method for dynamic crack propagation

2008 ◽  
Vol 30 (4) ◽  
Author(s):  
Pascal Aubertin ◽  
Julien Réthoré ◽  
René De Borst
Keyword(s):  
Finite Element Method ◽  
Molecular Dynamics ◽  
Finite Element ◽  
Extended Finite Element Method ◽  
Coupled Model ◽  
Partition Of Unity ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Extended Finite Element ◽  
Element Method

A multiscale method is presented which couples a molecular dynamics approach for describing fracture at the crack tip with an extended finite element method for discretizing the remainder of the domain. After recalling the basic equations of molecular dynamics and continuum mechanics the discretization is discussed for the continuum subdomain where the partition-of-unity property of finite element shape functions is used, since in this fashion the crack in the wake of its tip is naturally modelled as a traction-free discontinuity. Next, the zonal coupling method between the atomistic and continuum models is described, including an assessment of the energy transfer between both domains for a one-dimensional problem. Finally, a two-dimensional computation is presented of dynamic fracture using the coupled model.

Dynamic Crack Propagation and Arrest in PWR Pressure Vessel Steel: Interpretation of Experiment With the X-FEM Method

2007 ◽  
Author(s):  
B. Prabel ◽  
S. Marie ◽  
A. Combescure
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Strain Rate ◽  
Thermal Shock ◽  
Crack Growth ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Pressure Vessel Steel ◽  
Vessel Steel

In the frame of analysis of the pressure thermal shock in a PWR RVP and the associated R&D activities, some developments are performed at CEA on the dynamic brittle propagation and crack arrest. This paper presents a PhD work on the modeling of the dynamic brittle crack growth. For the analyses, an important experimental work is performed on different geometries using a French RPV ferritic steel: Compact Tension specimens with different thickness, isothermal rings under compression with different positions of the initial defect to study a mixed mode configuration, and a ring submitted to thermal shock. The first part of this paper details the test conditions and main results. To propose an accurate interpretation of the crack growth, a viscous-elastic-plastic dynamic model is used. The strain rate influence is taken into account based on Cowper-Symond’s law (characterization was made from Split Hopkinson Pressure Bar tests). To model the crack propagation in the Finite Element calculation, eXtended Finite Element Method (X-FEM) is used. The implementation of these specific elements in the CEA F.E. software CAST3M is described in the second part of this paper. This numerical technique avoids re-meshing, because the crack progress is directly incorporated in the degrees of freedom of the elements crossed by the crack. The last part of this paper compares the F.E. predictions to the experimental measurements using different criteria. In particular, we focused on a RKR (Ritchie-Knott-Rice) like criterion using a critical principal stress in the front of the crack tip during the dynamic crack extension. Critical stress is found to depend on crack speed, or equivalently on strain rate. Good results are reported concerning predictive simulations.

Dynamic crack propagation analysis based on the s-version of the finite element method

2020 ◽  
Vol 366 ◽  
pp. 113091
Author(s):  
Kota Kishi ◽  
Yuuki Takeoka ◽  
Tsutomu Fukui ◽  
Toshiyuki Matsumoto ◽  
Katsuyuki Suzuki ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Crack Propagation ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
The Finite Element Method ◽  
Propagation Analysis ◽  
Element Method
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