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Post-doc 18 months - highly competitive European Space Agency - EMTD Lab post-doc position - Interdisciplinary Centre for Security and Trust

Dear Colleagues We are looking for a post-doctoral level researcher for a 18 month project in collaboration with a startup company EMTD lab and the European Space Agency. The work to be done is related to radiation shielding and fatigue fracture. We are looking for people with a background in polycrystalline fracture, phase field/enriched finite element methods and multi-scale methods. Knowledge of metallurgy and crystallography would be welcome. Due to confidentiality, we cannot divulge more information at this stage.

Erik Bitzek's picture

Three Ph.D. Positions in Computational Atomistic Modeling

The Department of Materials Science and Engineering of the Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg is inviting applications for three doctoral research positions to begin immediately. The successful applicants will work together with Prof.

Jabar's picture

Fracture mechanism in notched metal

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G'day all

Having a metal element with a notch like crack (assume sharp one, exhibits plasticity),  what are the actual fracture mechanism (the phases the crack goes through) in the total fatigue-life. 

please comment on these scenarios:

1- crack initiation life calculated from the (S-N, e-N), then using LEFM/EPFM to determine the cycles for the crack propagation to failure...

Q/ how to find the crack length between the two phases, I mean from which stresses and at which crack length we start the crack propagation life estimation.

pragtic's picture

WCFA workshop on Design and Fatigue of Weldments

This is the second announcement about the upcoming Workshop on Computational Fatigue Analysis 2017, this year dedicated to Design and Fatigue of Weldments (WCFA2017-DFW - http://www.pragtic.com/DFW.php). The workshop is held in Prague, Czech Republic in November 13-16, 2017. The key lecturer, who guides the audience through various issues of the fatigue analysis in welds, is Dr Zuheir Barsoum from KTH - Royal Institute of Technology in Sweden.

Erik Bitzek's picture

Fundamentals of Fracture Symposium at DPG-EPS Meeting 2018

Sandra Korte-Kertzel, Peter Gumbsch and I are organizing a Symposium on the Fundamentals of Fracture

at the joint meeting of the German and European Physical Societies (DPG and EPS) in Berlin, March 11-13 2018.

 

saberelarem's picture

Nonlinear dynamics of rotating shaft with a breathing crack - CHINA SCHOLARSHIP COUNCIL PhD for 2017

Because of the increasing need of energy, the plants installed by electricity supply utilities throughout the world are becoming larger and more highly stressed. Thus, the risk of turbogenerator shaft cracking is increasing also. The development and propagation of a crack represents the most common and trivial beginning of integrity losses in engineering structures.

Lazuardi Pujilaksono's picture

Fatigue crack propagation

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Hi, I'm trying to perform a supposedly-simple experiment on fatigue crack propagation of UHMWPE. I use a compact-tension specimen on a servopulser hidraulic testing machine. I will try to do the experiment on a fix Pmax with a varied force ratio (R) from 0.1 to 0.5. I'm having trouble in deciding the maximum force Pmax. How does one decide the amount of force applied for FCP testing? Calculation steps and so on.

crack propagation in Abaqus (VCCT) with remeshing

I started using VCCT with quarter tip elements in Abaqus (not XFEM). I can solve the problem and get the SIFs.
How can I let the crack grow? Has someone a script for crack growth and remeshing that I can implement?

Modeling with line spring elements to find failure pressure of steam generator tube

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Hello, All
I am trying to model steam generator tube of length 110 , radius 11mm, thickness 1.27mm. It has 2 axial cracks of length 6.35mm. length between 2 cracks is 0.254mm. 

Project Fellow (PhD) position for Indo-China project in Computational Mechanics

The project is between BITS Pilani (India) and Wuhan University (China), funded by the Ministry of Mines, Govt. of India. It is in the area of computational fracture mechanics.

Details of the project and application process is in the attachment.

ndaphalapurkar's picture

Postdoc position – Modeling dynamic fracture and fragmentation

A Postdoctoral fellowship is available at The Johns Hopkins University, Baltimore, U.S.A. in the area of fracture and fragmentation under dynamic loading conditions. The potential candidate should have a Ph.D. in an engineering discipline, a strong background in fracture mechanics and extensive computational modeling experience working with the finite element methods or some other numerical method with application to solid mechanics.

Probing the intermediate states between rolling-up and wrinkling thin films

Self-positioned nanomembranes such as rolled-up tubes and wrinkled thin films have been potential systems for a variety of applications and basic studies on elastic properties of nanometer-thick systems. Although there is a clear driving force towards elastic energy minimization in each system, the exploration of intermediate states where specific characteristics could be chosen by a slight modification of a processing parameter had not been experimentally realized.

Elliptic crack instead of line crack in Phase-field method

What should be the crack initial condition in phase field fracture simulation?

By using phi=0 (broken phase) for one line segment of nodes  crack can
be specified. but with the loading applied we expect some crack opening
displacement. now as there is only one node specifying both upper and
lower crack faces displacements +u and -u at that node will be zero. 

Phase-field modelling of crack in fixed grid

In phase field method how one can specify the crack in fixed grid?

In case of finite element method one uses two overlapping nodes to model crack, which nodes separate after crack propagation. In case of phase-field, generally people use fixed grid finite difference method. My question is how the same node point can show two different displacements when crack has passed through it like FEM?

Debonding simulation - XFEM fracture criterion - delamination

Hello

I am using Abaqus/CAE 6.10 to simulate a Debonding test (cohesive behavior for composite delamination). 

I ran a Abaqus debonding simulation example (from Abaqus online documentation - Abaqus Benchmark Manual - 2.7.1 Delamination analysis of laminated composites).

The Abaqus/Explicit three-dimensional model with surface-based traction-separation behavior used a surface contact interaction property with:

- default Cohesive behavior

- XFEM-based LEFM (using VCCT) fracture criterion.

Konstantin Volokh's picture

Crack thickness

Macroscopic
cracks do not appear as a result of an ideal separation of two adjacent atomic
layers. Just the opposite, cracks appear as a result of the development of
multiple micro-cracks triggered by the massive breakage of atomic bonds. The microcracking
and the bond breakage are not confined to two neighbor atomic planes: the
process involves thousands atomic planes within the representative characteristic
volume of size h. This size defines the width (not the lenth) of the damage
localization zone and it can be called the crack thickness. The knowledge of

How to plot Fracture toughness vs Crack length in Abaqus for Delamination problem

I've modelled a DCB specimen and applied Boundary conditions and load... I followed the same procedures given in abaqus documentation... As expected the crack initiates and propagates along the interface... I can get the Resultant force vs displacement plot from the analysis.. But i dont know how to plot the fracture toughness vs crack length plot in ABAQUS..

Please help me... Your suggestion would really help me a lot..

droptest of model having crack in it in ABAQUS

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Hello,

I have a question to Abaqus users,

Can I simulate a drop-test of a model having crack in it in Abaqus/explicit.

If yes, whether Contour integral crack type can be used or I have to use XFEM?

Reply asap

MAil id-rbhute95@gmail.com 

 

XFEM, Damage Evaluation

Dear Colleague 

I am modelling a 2D three point bending to analysis the crack propagation , i have a question in the part of damage evaluation, does anybody know what is different between, B.K , power law and mod.independent? means when we select one of them. Thanks  

hanrrycn's picture

how to define cohesive element property? because the cohesive element layer is our imaginary

I'm modeling rock fracture problem with cohesive element. I konw the propertiey of the solid element around the fracture because we can measure it (rock sample) in the lab. but as regard to how to define the propeties of cohesive element, I'm completely lost.

in fact, the cohseive element is a fictitious one, not a real matearial in the physical world, we can't mearsure its propety by physical means. then how can we know what parameters we should enter ?

need your help, thanks

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