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Survey on XFEM: is XFEM good at characterizing Failure rather than Fracture?

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

Water Content In Exhaust Gas (Diesel Fuel)

Hi everyone,

I would like to know if anyone would be able to help me calculate(or measure) accurately the Moisture Content / Water vapour content in the Exhaust Gas of an Engine.

I wish to determine the components of the Exhaust Gas for a Combustion Chamber(so that I am able to calculate the Gas Constant of the Exhaust Gas) and

 I have been able to measure the values of Oxygen(in %), Carbon di oxide(in %), Carbon monoxide(in PPM), NOx (in PPM).

The components that I am taking into account for the Gas Constant calculation are O2, CO2, N2 and H2O.

Crack length in fracture mechanics


I have modeled a beam with a hole in it in ABAQUS. I use of FRACTURE MECHANICS and FINITE ELEMENT METHOD for perdiction of failure load of beams with holes. I am wondering is it a correct assumption to assume a fixed crack length for one beam with varying hole position or not? 

It have assumed that a fixed crack length for a beam with varying location of hole along the beam.

Am I correct?

Thank you,


Stiffness of a beam


As a part of my research, I would like to break down a simply supported beam to two beams shown in the attachement.  I expect to remove the bond and use of springs for transforming deformation of upper beam to lower beam. What could be the stiffness of springs which could be used in new model?

Thank you for your comment,



Operations with sparse matrices

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Dear mechanicians,

Stiffness matrix from ANSYS Classic

I want to get stiffnes matrix from ANSYS Classic. I used substructure analysis and using list->other-> super element data and got stiffness matrix of whole structure. But I want to get stiffness matrix of individual elements. Can I do it in ANSYS Classic?


notch tip radius

Hello everyone,


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, 

Nonlinear deformation analysis of CNTs with higher order Cauchy-Born rule based constitutive model


   Recently, we have developed a so-called higher order Cauchy-Born rule based
   constitutive model for the analysis of large deformation of CNTs [1]. It is
   a generalized quasi-continuum model for nano-structures.

What is the equation of formula to calculate flexural rigidity of RC Slab

Dear eveyone,

I need to know the formula or expression to calculate the flexural rigidity (D) of RC Slab reiforced with steel bars. I know that for plain concrete, D can be taken as Et3/12(1-v2). However, I have no idea what is D when steel bars are added to slab. I really appreciate for any kind help. Thanks

the fatigue limit and the long-crack threshold of Aluminum 2024-T3

Hellow,everyone here:
      Anyone knows  the fatigue limit and the long-crack threshold of Aluminum 2024-T3?Thanks very much.

Solution for beam on elastic beam


I am looking at some deformations in beams.  I have an elastic beam sleeping on another elastic beam and connected via springs that have two dimensional stiffness. Anybody knows how should I go for closed form solution of this beam and obtain deformations in springs??? I can model it in sap2000 or ABAQUS and solve it at there but I am now looking for only closed form solution... Besides, I am looking for deformations in spring caused by applied load. I have attached a sketch of my model. Any idea or comment will be highly appreciated.

Thank you for your comment, 

Adhesion between transferrable monolayer and substrate ?


Is there any research about  interfacial adhesion of  transferrable monolayers and substrates ? I found it's quite different from the rough surface model, because the monolayer is flexible enough to match the roughness of surface. Can one determine the separation value from the different roughness of pure substrate and substrate with a monolayer ?

Can someone give me some clue ? Thanks a lot!

Cyclic thermal load

I need to apply cyclic thermal load on a layered structure and want to see the stress generated and structural displacement using Ansys. How can I apply cyclic thermal load? iI tried to use Load Step Opts. Since I am interested only in stress-displacemnt, I used structural element. But if i use structural element, it doesn't give me Time/frequency option under load Step. Do i need to use coupled element? Is there any other way to apply cyclic thermal load to see stress-displacement? Thanks!


dabiao liu's picture

about critical thickness theory

who  can tell me more about the critical thickness theory ?I will be very excited if you   can introduce some reference to me.I know that critical thickness theory is solved rigorously and ursed to validated a useful approximation which is combined with slip distance theory modified for a finite structure size . (physical life review letters :elastic limit and strain hardening of thin wires in torsion)

Human conditioning

Instead of cooling a whole room some mechanism should be devised to cool only the human body thats only d requirement and can save energy its like mobile u can have it when u need.

Supplier and price details

I am unable to trace the suppliers of PEEK polymer in india. I am worried its price details too. Please help me out. sorry commercial agents.

Molecular statics

Is any one familiar with molecular statics.

3D Doctor Tool



I hope this is the right forum to get some help for my work. 

I am looking at CT data (DICOM files) to make FEM models. To generate 3D surface/volumes for FEM, I was looking for softwares. They all are pretty expensive (4-10K USD). I have decide togo with Able Software's 3D-DOCTOR. I am lookign for some reviews or user experience or comments for this tool.




FEM simulation on damage of brittle materials with Abaqus on mesoscale

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Hi, Smile

I'm a fresher in abaqus. Now I'm trying to simulate the damage of brittle kind of materials, like concrete with abaqus on mesoscale. But there are some problems now...

Shuozhi Xu's picture

The potential for Vanadium in molecular dynamic simulation

One of the most significant factors in molecular dynamic simulatin is to choose the proper potential. Recently, I did some searching jobs on Vanadium (V) potential and finally decided which potential I am going to use. Here is a simple summary:
A brief introduction of EAM, F-S and MEAM potentials for BCC transition metals


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