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Tiaxiality in unit cell calculation

Dear imechanica Members,

I want to make a comparison between the results of a calculation of unit cell model and Gurson but I have a little problem on the triaxiality.

How to use the Riks algorithm in AbaqusCAE that the triaxiality remains constant during the loading of a unit cell?

Thank you for your help.

Best regards

asit_rathod1's picture

MPC omega method

Hello All..

i am finding the MPC omega method for the devlopment of Isochronous which i am searching in the ASME catalogue but it will want 599$ so it will not affodable anybody who will guide me..


Asit Rathod

about the multiscale aggregating method (MAD) of Prof. Belytschko

Hello all

I have spent a large amount of time trying to undertstand the multiscale aggregating method (MAD) of Prof. Belytschko. Unfortunately, I still can not compltely understand the method. 

If there is anyone here in the forum already gets clear about the method, please help me.


Using ABAQUS subroutine (UMAT,VUMAT) to modeling FGM plate

Hello every body

I am working on modeling FGM plate in abaqus6.8,i know that it's possible to modeling FGP by using UMAT subroutine for definig variation of material's properties,but i don't know how can i use this subroutine,could you tell me please?

buckling analysis

hi all,

 I am doing buckling analysis of pressure vessel. I want to check the buckling load for individual components.

This pressure vessel is subject to hydrostatic pressure.

So if i want to check this, how to do that. I am not perticular about the softwares.


kirankumarkabothu's picture

conventional turning operration

i what matlab programing  for modeling of conventional turning forces (fx,fy,fz) predictions

software for strain field measurement in coupon tension tests


i am looking into strain field measurement for coupon tension tests for the purpose of correlation to fea results . a collegue told me that there is an open source project

which calculates strain field from camera images. does anybody know something about it?



Question on non-linear iteration in cases of force-controlled loading and displacement-controlled loading

In all textbooks, when iteration methods are introduced, the iterative formula is always H(x)x+f=0, where f is the external force applied on the system. All methods are stated when f is fixed.

Question on the definitions of secant stiffness and tangent stiffness in iterative methods for non-linear problems

Recently, I find that definitions of secant stiffness and tangent stiffness in many books seem pretty confused.Therefore, here I am giving the definitions I think correct, then give my questions on them.

Consider the equation


(1) Definition of tangent stiffness. As for the above equation, what is the tangent stiffness for some particular value x0?

Shape memory alloy material models including plasticity implemented in ABAQUS

I am working with shape memory alloys (nitinol), and am in that respect investigating fracture behaviour of NiTi, using, among other things, simulations in ABAQUS. ABAQUS doesn't have a material model that include plasticity unless you pay for it. I am wondering if anyone have implemented either of the following models as a UMAT, and if you are willing to share the code with me.

The models I am interested in are:

My newest metamaterial paper: Power loss and electromagnetic energy density in a dispersive metamaterial medium

Phys. Rev. E 80, 046601 (2009) [5 pages]
Power loss and electromagnetic energy density in a dispersive metamaterial medium

Pi-Gang Luan
Wave Engineering Laboratory, Department of Optics and Photonics, National Central University, Jhungli 320, Taiwan

Received 8 March 2009; revised 11 July 2009; published 5 October 2009

The effects of boron dopings and boron grafts on the mechanical properties of single-walled carbon nanotubes

The effects of boron doping and boron grafts on the mechanical behaviour of armchair (6, 6)
and zigzag (10, 0) single-walled carbon nanotubes (SWCNTs) under axial loading are
investigated using the molecular dynamics (MD) simulation method. The results show that
Young’s moduli, the tension strength, the buckling loads and the buckling strains of SWCNTs
decrease after functionalization. The influences of the distribution density of functionalization
on Young’s moduli of SWCNTs are also systematically studied. The results show that Young’s

Ning Wang's picture

Embryonic stem cell softness dictates stress-induced spreading and differentiation

We recently find that embryonic stem cells are very sensitive to a local cyclic stress applied to the focal adhesion.  They spread and differentiate (Oct3/4 downregulation) in response to this local force.

Effective strain rate and strain rate in ABAQUS subrotine

Hi there,

would you please tell me how can I use or calculate the effective strain rate or strain rate in ABAQUS subrotine?

 thank you!

Concrete Damaged Plasticity

Choose a channel featured in the header of iMechanica: 

Hi, I am currently trying to model a RC connection and I am using Concrete Damaged Plasticity, CDP, to model my concrete. WIthin this model, you would need to specify the tension damaged against strain or displacement. I have looked through the literature, there are many papers that talk about the damage, but they do not show how the tension damage was obtained.

Force Matrix for Transient Thermal Analysis

Choose a channel featured in the header of iMechanica: 


I have developed a 2D transient thermal analysis FE code which doesn't
seem to be correct. I am sure there is a conceptual problem in the
formulation itself which I have not been able to understand and could
not find concrete information in books.

I am putting up the question in a very simplified form so as to address the correctness of the formulation.

Help For learning Abaqus

Hi dears

Would you help me about Abaqus learning?

As I search in diffrent web pages and data base 

there is not  enough refrences about abaqus tutorials 

so How can I learn it as a begining user?

thanks for your help

good luck

Kaushik Dayal's picture

Nonequilibrium molecular dynamics for bulk materials and nanostructures

This is a preprint that of an article that will appear in J. Mech. Phys. Solids. (doi: 10.1016/j.jmps.2009.10.008).  Nonequilibrium molecular dynamics for bulk materials and nanostructures,
by Kaushik Dayal and Richard D. James

Teng Li's picture

A quality map of transfer printing

M.B. Tucker, D.R. Hines, T. Li, A quality map of transfer printing, Journal of Applied Physics, 106, 103504, (2009)  DOI: 10.1063/1.3259422


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