Peer review report 4 on “Modeling damage growth using the crack band model; effect of different strain measures”

2015 ◽  
Vol 133 ◽  
pp. 134
Author(s):  
H. Wang
Keyword(s):  
Peer Review ◽  
Band Model ◽  
Damage Growth ◽  
Crack Band ◽  
Strain Measures

A Continuum Damage Model for Functionalized Graphene Membranes Based on Atomistic Simulations

2017 ◽  
Vol 754 ◽  
pp. 173-176
Author(s):  
Ivano Benedetti ◽  
R.A. Soler-Crespo ◽  
A. Pedivellano ◽  
Wei Gao ◽  
H.D. Espinosa
Keyword(s):  
Continuum Model ◽  
Damage Model ◽  
Atomistic Simulations ◽  
Band Model ◽  
Continuum Damage ◽  
Two Phase ◽  
Elastic Continuum ◽  
Continuum Damage Model ◽  
Crack Band ◽  
Hyper Elastic

A continuum model for GO membranes is developed in this study. The model is built representing the membrane as a two-dimensional, heterogeneous, two-phase continuum and the constitutive behavior of each phase (graphitic or oxidized) is built based on DFTB simulations of representative patches. A hyper-elastic continuum model is employed for the graphene areas, while a continuum damage model is more adequate for representing the behavior of oxidized regions. A finite element implementation for GO membranes subjected to degradation and failure is then implemented and, to avoid localization instabilities and spurious mesh sensitivity, a simple crack band model is adopted. The developed implementation is then used to investigate the existence of GO nano-representative volume elements.

Microplane Model for Fracturing Damage of Triaxially Braided Fiber-Polymer Composites

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Ferhun C. Caner ◽  
Zdeněk P. Bažant ◽  
Christian G. Hoover ◽  
Anthony M. Waas ◽  
Khaled W. Shahwan
Keyword(s):  
Present Model ◽  
Material Model ◽  
Multiscale Model ◽  
Stress And Strain ◽  
Band Model ◽  
Braided Composites ◽  
Microplane Model ◽  
Explicit Finite Element ◽  
Crack Band ◽  
Strain Tensors

A material model for the fracturing behavior for braided composites is developed and implemented in a material subroutine for use in the commercial explicit finite element code ABAQUS. The subroutine is based on the microplane model in which the constitutive behavior is defined not in terms of stress and strain tensors and their invariants but in terms of stress and strain vectors in the material mesostructure called the “microplanes.” This is a semi-multiscale model, which captures the interactions between inelastic phenomena such as cracking, splitting, and frictional slipping occurring on planes of various orientations though not the interactions at a distance. To avoid spurious mesh sensitivity due to softening, the crack band model is adopted. Its band width, related to the material characteristic length, serves as the localization limiter. It is shown that the model can realistically predict the orthotropic elastic constants and the strength limits. More importantly, the present model can also fit the tests of size effect on the strength of notched specimens and the post-peak behavior, which have been conducted for this purpose. When used in the ABAQUS software, the model gives a realistic picture of the axial crushing of a braided tube by a divergent plug.

scholarly journals Development and Evaluation of Crack Band Model Implemented Progressive Failure Analysis Method for Notched Composite Laminate

2019 ◽  
Vol 9 (24) ◽  
pp. 5572
Author(s):  
Donghyun Yoon ◽  
Sangdeok Kim ◽  
Jaehoon Kim ◽  
Youngdae Doh
Keyword(s):  
Failure Analysis ◽  
Failure Criterion ◽  
Composite Laminate ◽  
Progressive Failure ◽  
Numerical Results ◽  
Band Model ◽  
Failure Initiation ◽  
Progressive Failure Analysis ◽  
Crack Band ◽  
Tension And Compression

Progressive failure analysis (PFA) is widely used to predict the failure behavior of composite materials. As a structure becomes more complex with discontinuities, prediction of failure becomes more difficult and mesh dependence must be taken into account. In this study, a PFA model was developed using the Hashin failure criterion and crack band model. The failure initiation was evaluated using the Hashin failure criterion. If failure initiation occurred, the damage variables at each failure mode (fiber tension and compression; matrix tension and compression) were calculated according to linear softening degradation and they were then used to derive the damaged stiffness matrix. This matrix reflected a degraded material, and PFA was continued until the damage variables became “1,” implying complete material failure. A series of processes were performed using the finite element method program ABAQUS with a user-defined material subroutine. To evaluate the proposed PFA model, experimental results of open-hole composite laminate tests were compared with the obtained numerical results. The strain behaviors were compared using a digital image correlation system. The obtained numerical results were in good agreement with the experimental ones.

A Comparison of Cohesive Crack Model and Crack Band Model in Concrete Fracture

2012 ◽  
Vol 170-173 ◽  
pp. 3375-3380
Author(s):  
Liang Wu ◽  
Ze Li ◽  
Shang Huang
Keyword(s):  
Fracture Process ◽  
Fracture Process Zone ◽  
Process Zone ◽  
Crack Opening ◽  
Cohesive Crack ◽  
Band Model ◽  
Crack Model ◽  
Concrete Fracture ◽  
Cohesive Crack Model ◽  
Crack Band

The cohesive crack model and the crack band model are two convenient approaches in concrete fracture analysis. They can describe in full the fracture process by the different manner: The entire fracture process zone is lumped into the crack line and is characterized in the form of a stress-displacement law which exhibits softening; or the inelastic deformations in the fracture process zone are smeared over a band of a certain width, imagined to exist in front of the main crack. The correlation of the two models is developed based on a characteristic width of crack band. The analysis shows that they can yield about the same results if the crack opening displacement in the cohesive crack model is taken as the fracturing strain that is accumulated over the width of the crack band model. Some basic problems are also discussed in finite element analysis.

scholarly journals Numerical simulation of earth fissures due to groundwater withdrawal

2015 ◽  
Vol 372 ◽  
pp. 395-398 ◽  
Author(s):  
Z. Wang ◽  
Y. Zhang ◽  
J. Wu ◽  
J. Yu ◽  
X. Gong
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Finite Elements ◽  
Groundwater Withdrawal ◽  
Tensile Failure ◽  
Band Model ◽  
Field Observations ◽  
Earth Fissures ◽  
Initiation And Propagation ◽  
Crack Band

Abstract. Excessive groundwater withdrawal can cause land subsidence and earth fissures. The initiation and propagation of earth fissures are related to tensile failure and crack propagation in soils. Based on fracture mechanics, the crack band model (CBM), one of the smear crack models which is relatively easy to construct and convenient to be integrated into standard finite element codes is used in this paper. The calculated results of CBM are less dependent on the sizes of finite elements. The model was applied to simulate the formation and propagation of earth fissures in the hydrostratigraphic units with a bedrock ridge. The simulated positions and patterns of earth fissures coincide with field observations, suggesting that the modeling approach is adept to simulate the initiation and propagation of earth fissures due to groundwater withdrawal.

A Probabilistic Crack Band Model for Quasibrittle Fracture

2016 ◽  
Vol 83 (5) ◽  
Author(s):  
Jia-Liang Le ◽  
Jan Eliáš
Keyword(s):  
Probability Distributions ◽  
Distribution Functions ◽  
Material Strength ◽  
Band Model ◽  
Quasibrittle Fracture ◽  
Damage Initiation ◽  
Nominal Strength ◽  
Crack Band ◽  
Random Location ◽  
Constitutive Parameters

This paper presents a new crack band model (CBM) for probabilistic analysis of quasibrittle fracture. The model is anchored by a probabilistic treatment of damage initiation, localization, and propagation. This model regularizes the energy dissipation of a single material element for the transition between damage initiation and localization. Meanwhile, the model also takes into account the probabilistic onset of damage localization inside the finite element (FE) for the case where the element size is larger than the crack band width. The random location of the localization band is related to the random material strength, whose statistics is described by a finite weakest link model. The present model is applied to simulate the probability distributions of the nominal strength of different quasibrittle structures. It is shown that for quasibrittle structures direct application of the conventional CBM for stochastic FE simulations would lead to mesh-sensitive results. To mitigate such mesh dependence, it is essential to incorporate the strain localization mechanism into the formulation of the sampling distribution functions of material constitutive parameters.

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