scholarly journals Simulation of crack propagation based on eigenerosion in brittle and ductile materials subject to finite strains

2022 ◽  
Author(s):  
Dennis Wingender ◽  
Daniel Balzani
Keyword(s):  
Cyclic Loading ◽  
Crack Propagation ◽  
Ductile Fracture ◽  
Finite Strains ◽  
Benchmark Problems ◽  
Unified Approach ◽  
Ductile Materials ◽  
Strain Formulation ◽  
Viscous Regularization ◽  
Shear Band Localization

AbstractIn this paper, a framework for the simulation of crack propagation in brittle and ductile materials is proposed. The framework is derived by extending the eigenerosion approach of Pandolfi and Ortiz (Int J Numer Methods Eng 92(8):694–714, 2012. 10.1002/nme.4352) to finite strains and by connecting it with a generalized energy-based, Griffith-type failure criterion for ductile fracture. To model the elasto-plastic response, a classical finite strain formulation is extended by viscous regularization to account for the shear band localization prior to fracture. The compression–tension asymmetry, which becomes particularly important during crack propagation under cyclic loading, is incorporated by splitting the strain energy density into a tensile and compression part. In a comparative study based on benchmark problems, it is shown that the unified approach is indeed able to represent brittle and ductile fracture at finite strains and to ensure converging, mesh-independent solutions. Furthermore, the proposed approach is analyzed for cyclic loading, and it is shown that classical Wöhler curves can be represented.

scholarly journals Benchmark Analysis of Ductile Fracture Simulation for Circumferentially Cracked Pipes Subjected to Bending

2021 ◽  
Author(s):  
Tomohisa Kumagai ◽  
Yasufumi Miura ◽  
Naoki Miura ◽  
Stephane Marie ◽  
Remmal Almahdi ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Ductile Fracture ◽  
Stress Triaxiality ◽  
Benchmark Problems ◽  
Simulation Methods ◽  
Ductile Crack ◽  
Cyclic Bending ◽  
Fracture Simulation ◽  
Deformation And Fracture ◽  
Fracture Behaviors

Abstract To predict fracture behavior for ductile materials, some ductile fracture simulation methods different from classical approaches have been investigated based on appropriate models of ductile fracture. For the future use of the methods to overcome restrictions of classical approaches, the applicability to the actual components is of concern. In this study, two benchmark problems on the fracture tests supposing actual components were provided to investigate prediction ability of simulation methods containing parameter decisions. One was the circumferentially through-wall and surface cracked pipes subjected to monotonic bending, and the other was the circumferentially through-wall cracked pipes subjected to cyclic bending. Participants predicted the ductile crack propagation behavior by their own approaches, including FEM employed GTN yielding function with void ratio criterion, are FEM employed GTN yielding function, FEM with fracture strain or energy criterion modified by stress triaxiality, XFEM with J or ?J criterion, FEM with stress triaxiality and plastic strain based ductile crack propagation using FEM, and elastic-plastic peridynamics. Both the deformation and the crack propagation behaviors for monotonic bending were well reproduced, while few participants reproduced those for cyclic bending. To reproduce pipe deformation and fracture behaviors, most of groups needed parameters which were determined to reproduce pipe deformation and fracture behaviors in benchmark problems themselves and it is still difficult to reproduce them by using parameters only from basic materials tests.

Ductile Fracture of a Marine Structural Steel based on HC-DSSE Combined Fracture Strain Formulation

2019 ◽  
Vol 56 (1) ◽  
pp. 82-93
Author(s):  
Sung-Ju Park ◽  
Kangsu Lee ◽  
Burak Can Cerik ◽  
Younghyn Kim ◽  
Joonmo Choung
Keyword(s):  
Ductile Fracture ◽  
Structural Steel ◽  
Fracture Strain ◽  
Strain Formulation

Crack initiation and crack propagation under thermal cyclic loading

1990 ◽  
Vol 8 (2) ◽  
pp. 98-104 ◽  
Author(s):  
K. Bethge ◽  
D. Munz ◽  
J. Neumann
Keyword(s):  
Cyclic Loading ◽  
Crack Initiation ◽  
Crack Propagation

Crack Propagation Prediction Using Haensel Damage Model

2012 ◽  
Author(s):  
Piotr Bednarz ◽  
Jaroslaw Szwedowicz
Keyword(s):  
Cyclic Loading ◽  
Crack Initiation ◽  
Crack Propagation ◽  
Damage Model ◽  
Lifetime Prediction ◽  
Dissipated Energy ◽  
Mathematical Approach ◽  
Loading Conditions ◽  
Stored Energy ◽  
Tensile Stresses

The Haensel damage model correlates lifetime of a component until crack initiation to the dissipated and stored energy in the material during cyclic loading. The crack initiation is influenced by mean stresses. The Haensel damage model considers the mean stress effect by including compressive and tensile stresses in calculations of elastic strain energy during cyclic loading conditions. The goal of the paper is to extend the above model to predict crack propagation under large cyclic plasticity and non-proportional loading conditions. After voids initiation onset of necking, voids growth and linking takes place among them. During this process a mesocrack is created. This stage of fracture involves the same amount of released energy for new crack surface creation as dissipated energy for mesocrack initiation. The amount of dissipated and stored energy is related to the process zone size and to the number of cycles. Ilyushin’s postulate is used to calculate the amount of dissipated energy. In order to consider a contribution of tensile stresses only during loading to crack propagation, tensile/compressive split is performed for the stress tensor. One of the key drivers of this paper is to provide a straightforward engineering approach, which does not require explicit modelling of cracks. The proposed mathematical approach accounts for redistribution of stresses, strains and energy during crack propagation. This allows to approximate the observed effect of distribution of dissipated energy on the front of a crack tip. The developed approach is validated through FE (Finite Element) simulations of the Dowling and Begley experiment. The Haensel lifetime prediction of Dowling’s experiment is in good agreement with the experimental data and the explicit FE results. Finally, the proposed mathematical approach simplifies significantly the engineering effort for Nonlinear Fracture Mechanics lifetime prediction by avoiding the requirement to simulate real crack propagation using node base release methods, XFEM or remeshing procedures.

Dependency of mesh size and loading history on crack propagation energy of cyclic ductile fracture model

2019 ◽  
Vol 215 ◽  
pp. 117-137 ◽  
Author(s):  
Liang-Jiu Jia ◽  
Wataru Fujie ◽  
Toyoki Ikai ◽  
Soichiro Yoshida ◽  
Hanbin Ge
Keyword(s):  
Crack Propagation ◽  
Ductile Fracture ◽  
Mesh Size ◽  
Fracture Model ◽  
Loading History ◽  
Ductile Fracture Model

Ductile Tearing Simulation of Circumferential Cracked Pipe Under Cyclic Loading Using Damage Criteria Determined by Monotonic Pipe Test Data

2018 ◽  
Author(s):  
Jin-Ha Hwang ◽  
Gyo-Geun Youn ◽  
Naoki Miura ◽  
Yun-Jae Kim
Keyword(s):  
Fracture Toughness ◽  
Cyclic Loading ◽  
Ductile Fracture ◽  
Test Data ◽  
Strain Energy ◽  
Fracture Strain ◽  
Damage Model ◽  
Fracture Toughness Test ◽  
Ductile Tearing ◽  
Damage Criteria

To evaluate the structural integrity of nuclear power plant piping, it is important to predict ductile tearing of circumferential cracked pipe from the view point of Leak-Before-Break concept under seismic conditions. CRIEPI (Central Research Institute of Electric Power Industry) conducted fracture test on Japanese carbon steel (STS410) circumferential through-wall cracked pipes under monotonic or cyclic bending load in room temperature. Cyclic loading test conducted variable experimental conditions considering effect of stress ratio and amplitude. In the previous study, monotonic fracture pipe test was simulated by modified stress-strain ductile damage model determined by C(T) specimen fracture toughness test. And, ductile fracture of pipe under cyclic loading simulated using damage criteria based on fracture strain energy from C(T) specimen test data. In this study, monotonic pipe test result is applied to determination of damage model based on fracture strain energy, using finite element analysis, without C(T) specimen fracture toughness test. Ductile fracture of pipe under variable cyclic loading conditions simulates using determined fracture energy damage model from monotonic pipe test.

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