This is a review on ductile fracture committed to the Advances in Applied Mechanics (Vol 44). Part of the review has an educational purpose and, as such, is intended for advanced undergraduates and starting graduate students. The other part is an account of recent research conducted in the field.
Though quite long, the review is by no means exhaustive. As noted in the discussion, many valuable contributions to this field have been left out. The focus was laid on micromechanics-based approaches to connect to microstructural aspects in engineering materials.
I will try to post the electronic PDF once I get permission from Elsevier.
hi friends am doin my my project on" FEA of plasticity induced crack closure". my specimen size is 80*80 mm. by using symmetry condition i modelled 1/4th of model in ANSYS. therfore i created 40*40 mm plate. with initial crack length of 4mm.means its MT specimen of 80*80mm with 8 mm crack length, by symmetry condition i modelled 40*40 with 4mm crack lenth.
I am working with abaqus 6.7 software. I wish to simulate uni-axial tension and compression cyclic analysis. My objective is to predict the response of steel subjected to cyclic load and in particular, to predict ratcheting effect. I am also interested to draw S-N curve, stress-strain curve, ratcheting behaviour, etc. from the result of the analysis. I tried to simulate an axi-symmetric model and job submission is successfully completed. But I am not aware of the fact that how the results of analysis can be retrieved to draw the above mentioned curves, please specify how the 'no.of cycle' data can be obtained.
I am working on plastic behaviour of metal. I am using Abaqus 6.7 for simulation of uniaxial ratcheting of steel under cyclic loading. Modelling and job submission/completion has been done successfully. But I cann't understand where the data for Stresses(S) & number of cycle(N) is strored to draw S-N curve. Please suggest.
Concrete is sensitive to strain rate. I want to create a model for a reinforced concrete plane frame. The material model used for concrete is concrete damaged plasticity, and the element type is B21. I want to consider strain rate effects of concrete(strength). The problem is that ABAQUS can not work after considering strain rate effects of concrete when the concrete yields. Can you help me? Thank you in advance.
I am an M.S student, my subject in modelling of high strength concrete column under eecentric loading. I made a model of reinforced
concrete column with in ANSYS by solid65 to represent concrete and link8 for steel.
My model is 200*200*4000 mm, i choose multi., conc.,and elastic linear for concrete, closing crushing for it, for steel bilinear, elastic.
Slenderness ratio (l/d)=20 Although Using large displacement analysis option, model give me very small displacement (less than
I decided to put this post since I am trying to model piles on granular materials with Abaqus and I am having LOADS of problems, some of them due to my lack of understanding in the subject and others becasue there is not enough information around. Some of my problems are:
1- convergence problems: I am using Mohr coulomb for the soil and elasticity for the pile. If the difference between Young's modulus for both materials is to big it does not converge on Abaqus Static. If I do not put a bit of cohesion in my soil it also does not converge.
2- Different failure mode or smaller than it should be.
We are looking for suitable candidates for a PhD research work in Computational Mechanics and numerical simulation, to be carried out at the Department of Mechanical Engineering, University of Aveiro, Portugal, in one of the following areas:
- development of new finite elements for metal forming applications;
- numerical simulation of metal forming (sheet and bulk forming);
- tubular hydroforming numerical simulation;
- structural stability and buckling analysis of reinforced aircraft panels;
- integrated design, modelling and reliability assessment (iDMR) by computational tools.
Candidates are free to contact me using the email: robertt AT ua DOT pt
Would like to hear your expertise/user/non-expert/sceptic comments on XFEM. Here are some of the challenges. Would like to hear your relections.
1. Can XFEM be utilized in characterizing Failure rather than Fracture?
2. What sort of challenges XFEM still have with respect to Fracture Mechanics?
3. How the Fracture mechanics benefit the industry, from the perspective of strcutural integrity?
4. Failue investigations vs. Fracture investigations: benefit to industry?
5. Academist vs Engineer: Perspective on XFEM
If possible, please vindicate your justifications with any relevant literature. Would like to see where and how XFEM is evolving.
I am looking for a way to measure notch tip radius experimentally. Would you give me some ideas about that? is there any relationship between morphology of notched cracked body surface and notch tip radius?
Thank you and Regards,
PRL 104, 215503 (2010)
I am new in the Forum, and I am looking for some informations regarding how to simulate nonlinear material in explicit.
I am tryng to analyse the behaviour of a roller rolling on the sand (or mud), but the results I get with a basic elasto-plastic material are not very accurate, expecially because I cannot set the tension allowed in the sand to be zero.
Other ways to input nonlinearity in Explicit are always refused by ABAQUS. Is there any way to get something more accurate?
Since ABAQUS 6.8, a new feature has been added to the combined hardening
Let's assume a combined Kinematic and Isotropic hardening case, such as
those happen in metals.
"Half cycle" uni-axial test results has been utilized to model the yield
stress-plastic strain behavior as well as the Kinematic behavior of the
In the same user interface, there is an option to choose the number of
Is the number of 1 back stress is equivalen to the case of linear
kinematic hardening (Ziegler's)?
Since ABAQUS 6.8, a new feature has been added to the combined hardening material input.
Let's assume a combined Kinematic and Isotropic hardening case, such as those happen in metals.
"Half cycle" uni-axial test results has been utilized to model the yield stress-plastic strain behavior as well as the Kinematic behavior of the metals.
In the same user interface, there is an option to choose the number of back stresses.
Is the number of 1 back stress is equivalen to the case of linear kinematic hardening (Ziegler's)?
A postdoctoral fellow is sought to study the mechanics of magnesium alloys at the University of Waterloo, Canada, under the guidance of Dr. Worswick and Dr. Gracie. The qualified applicant will have a proven background in computational mechanics, substantiated by publications in international journals. Preference will be given to candidates with experience coding large deformation plasticity models, coding the finite element method and with using fracture mechanics. In addition, experience with high strain rate testing of materials is desirable.
Applications must include: a cover letter, a curriculum vitae and a list of references. .
The Graduate School MUSIC ("Multiscale Methods for Interface Coupling") and the
Institute of Continuum Mechanics at Leibniz Universität Hannover invites
applications for a position as a
Research Staff Member in Computational Mechanics
(Salary scale E13 TV-L)
to be appointed on 1 April 2010.
The position is embedded into the Junior Research Group on „Multiscale Modelling of
Materials and Interfaces with Size Effects” and is initially limited to 1 year.
Mechanics and Applications
An open access journal
I think that many students are looking for some tutorials about writing a UMAT in ABAQUS.
You can find a comprehensive tutorial for elastic problems.
This file contains:
• Steps Required in Writing a UMAT or VUMAT
Solids that are driven beyond their elastic limit exhibit strongly disspative and irreversible dynamical behaviors. Such behaviors call for the development of nonequilibrium approaches that go beyond standard equilibrium thermodynamics. In a recent work we have developed an internal-variable, effective-temperature non-equilibrium thermodynamics for glass-forming and polycrystalline materials driven away from thermodynamic equilibrium by external forces [1, 2]. The basic idea is that the slow configurational (structural) degrees of freedom of such materials are weakly coupled to the fast kinetic-vibrational degrees of freedom and therefore these two subsystems can be described by different temperatures during deformation. The configurational subsystem is defined by the mechanically stable positions of the constituent atoms, i.e. the "inherent structures", and is characterized by an effective temperature. The kinetic-vibrational subsystem is defined by the momenta and the displacements of the atoms at small distances away from their stable positions, and is characterized by the bath temperature.
Submitted to the Journal of Applied Mechanics on 2/1/2010.
(in Computational Methods for Microstructure-Property Relationships," Springer. Edited by Somnath Ghosh and Dennis Dimiduk)
Dislocation mediated continuum plasticity: case studies on modeling scale dependence, scale-invariance, and directionality of sharp yield-point
Claude Fressengeas, Amit Acharya, Armand Beaudoin
In case of elasto-plastic problem it is mentioned that unloading of an integration point should be started along the elastic moduli when the solution gives a negetive increment of the plastic strain at the integration point. If anyone could elaborate it a little more, it will be really helpful.