scholarly journals Finite element implementation of the coupled criterion for numerical simulations of crack initiation and propagation in brittle materials

2018 ◽  
Vol 93 ◽  
pp. 105-115 ◽  
Author(s):  
Jia Li ◽  
Dominique Leguillon
Keyword(s):  
Finite Element ◽  
Crack Initiation ◽  
Numerical Simulations ◽  
Brittle Materials ◽  
Crack Initiation And Propagation ◽  
Finite Element Implementation ◽  
Initiation And Propagation ◽  
Coupled Criterion

scholarly journals Numerical modelling strategies using implicit and explicit methods to simulate quasi-static and dynamic three-points bend fracture tests of a ductile steel

2021 ◽  
Vol 250 ◽  
pp. 02033
Author(s):  
Frédéric Nozères ◽  
Hervé Couque ◽  
Rémi Boulanger ◽  
Yann Quirion ◽  
Patrice Bailly ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Crack Initiation ◽  
Crack Initiation And Propagation ◽  
Initiation And Propagation ◽  
Fracture Tests ◽  
Point Bend ◽  
Dynamic Loading Conditions ◽  
Implicit And Explicit ◽  
Static And Dynamic Loading

Three-point bend fracture tests have been conducted at different loading rates with a quadratic martensitic steel. The failure energy has been found to increase with loading rate. To get insights in this increase a numerical investigation has been undertaken with different strategies using ABAQUS and IMPETUS softwares in order to address quasi-static and dynamic loading conditions. Simulations were conducted with the ABAQUS software in order to carry out a comparative analysis of both implicit and explicit approaches. In addition to standard Finite Element Method (FEM) applied to quasi-static and dynamic conditions, the eXtended-Finite Element Method (X-FEM) was applied to quasistatic conditions. In both approaches, implicit and explicit, crack initiation and propagation were governed by a critical plastic strain threshold combined with a displacement-based damage evolution criterion. Simulations conducted with the IMPETUS software use an explicit approach and second order elements for both quasi-static and dynamic loading conditions. A node-splitting method using an energy-based damage criterion was employed to simulate the crack initiation and propagation. Experimental data and numerical results have been compared, allowing to determine the ability of these two softwares to simulate accurately three-point bend fracture tests.

Study of Crack Initiation and Propagation in TBCs by Experiments and Extended Finite Element Method

2013 ◽  
Vol 331 ◽  
pp. 129-132 ◽  
Author(s):  
Jing Xin Su ◽  
Zhao Hui Ji ◽  
Zhi Yong Han ◽  
Hua Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Crack Initiation ◽  
Thermal Cycling ◽  
Extended Finite Element Method ◽  
Interface Roughness ◽  
Crack Initiation And Propagation ◽  
Extended Finite Element ◽  
Initiation And Propagation ◽  
Element Method

CoNiCrAlY bond coat (BC) and top ceramic coating (TCC) was fabricated on the GH99 super alloy by high velocity oxyfuel spray (HVOF) and air plasma spray (APS), respectively. Thermal cycling treatment was applied to the thermal barrier coatings (TBCs). The cross-sectional images of crack initiation and propagation of TBCs after treatment were investigated by scanning electron micrograph (SEM), meanwhile crack initiation and propagation in TBCs were analyzed based upon ABAQUS software using extended finite element method (XFEM). The results show that, crack initiation and propagation can be easily traced via microscopy at the interface areas in TBCs; after thermal cycling treatments, the crack associated with the TCC/TGO interface morphology initiates at interface peak area and propagates along TCC/TGO interface with thermal cycles; the interface roughness affects the crack magnitude in length and width obviously, the rougher the morphology, the bigger the crack is; the XFEM is a novel and effective method to well predict the crack initiation and calculate the crack propagation, and simulation and experimental results fit well.

scholarly journals Numerical modeling of crack initiation and propagation processes in various specimen’s types using the GTN material damage model

2021 ◽  
Vol 5 (1) ◽  
pp. 49-56
Author(s):  
Andrew Kravchuk ◽  
Eugene Kondriakov ◽  
Valery Kharchenko
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Crack Initiation ◽  
Damage Model ◽  
Material Damage ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Crack Initiation And Propagation ◽  
Initiation And Propagation

Problematic. A combination of experimental and computational methods for studying the processes of crack initiation and propagation in various specimen’s types is used to determine the mechanical properties of materials, as well as to improve the accuracy of assessing the strength and durability of structural elements. Research objective. Determination of the parameters of the Gurson-Tvergaard-Needleman (GTN) material damage model based on the numerical modeling results of various specimen’s types under various types of loading for steel 22K using the finite element method. Realization technique. Using the finite element method, numerical modeling of the processes of cracks nucleation and propagation in cylindrical specimens under uniaxial tension, in Charpy specimens under dynamic loading, and also in CT specimens under quasi-static loading was carried out for steel 22K using the GTN material damage model. The results of research. By comparing the experimental and numerical results, the full set of GTN material model parameters for steel 22K was determined. The stress state in the crack tip area and the kinetics of its propagation in the material of various specimen’s types under static and dynamic loading were estimated. Conclusions. The GTN material damage model with the parameter values determined from experiments, can be used for numerical simulation of the processes of crack initiation and propagation both in specimens of various types under various loading types, and in structural elements.

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