research

Kevin T Turner's picture

Journal Club February 2010: Mechanics of Patterned and Structured Interfaces

Welcome to February 2010 Journal Club!  This month, I look forward to a lively discussion on the mechanics of structured and patterned interfaces in which geometry is used to tailor adhesion.  Much of the work in this area has been inspired by a variety of animals and insects that have feet covered with small structures (often hierarchical and sub-micrometer in size at the end) that allow them to strongly adhere to a broad range of surfaces.  The best known example is the Tokay Gecko (Gekko gecko), which can achieve an adhesion force much greater than its body weight and can quickly form and separate adhesive contacts between their feet and a range of smooth and rough surfaces.  In the journal club this month I do not want to delve into the mechanics of Gecko a


Jizhou Song's picture

The Most-Cited Institutions in Engineering, 1999-2009

ScienceWatch.com (affiliated with Thomson-Reuters), has ranked University of Illinois as the most cited institution in engineering from 1999 to 2009 (http://sciencewatch.com/inter/ins/10/10febTOP20ENG/).  It is followed by Berkeley, MIT, Stanford, University of Michigan, and Georgia Tech.
 
For each institution, ScienceWatch.com has also listed a few research directions that have received most citations.  The mechanics work by Professors Yonggang Huang (University of Illinois), Huajian Gao (Brown University), Bill Nix (Stanford) and Hutchinson (Harvard) on Mechanism-based strain (gradient) plasticity leads the list from the University of Illinois.


Sprunger's picture

Download your Free Abaqus SE

Download your Free Abaqus SE at: http://campus.3ds.com/simulia/freese

SIMULIA Academic programs would like to offer you a complimentary copy of our Abaqus SE (student edition). Now students can have their own personal finite element analysis tool to use on or away from campus. Abaqus Student edition is ideal for students using Abaqus as part of their coursework as well as for practicing engineers who wish to become more proficient with Abaqus.


New idea in fatigue problems

there are two analytical concepts that are very important in fatigue failure.the first one is crack closure and the others is residual stress .the first one is in behind of crack and the other emphasis in the front of crack tip. the question is if we use some devices such as AFM/SEM is it possible we model the energy filed during fatigue process?   if this idea can be investigated the second question can be asked: is there any similarity to model for different loading conditions? 

 

I appreciate if you also put your comment in my idea?

 

Bes Regards,

Hadi 


Eran Bouchbinder's picture

Nonequilibrium Thermodynamics in Solid Mechanics

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.


karthirajme's picture

i need help - LS-DYNA Tutorial wants especially composite impact analysis

i need help - LS-DYNA Tutorial  especially composite impact analysis. so pls send a tutorial PDf file to my mail ID. karthirajme@gamil.com


karthirajme's picture

Design of GFRP Bumper for Automobile Application

hai my name is A.Karthikeyan. i am doing my Ph.D in Composite field especially impact analysis using Ansys LS-Dyna.


Question about Gyroscopic Effects

Gyroscopic effects is a very old topic.

When reading
literature, I am confused by the two concepts: "gyroscopic moment", and
"Coriolis force". Are they exactly the same thing or different? what's
the difference between them if different?


BoJing Zhu's picture

How to use ABAQUS deal with irregular interface problem?

As we know how to define the interface type is a key problem in ABAQUS.

 

But when the interface is not regular, can we find a convenient way to realize it?


Opening for new Ph.D. students in the Computational Mechanics group, The University of Iowa

The Computational Mechanics group at The University of Iowa, led by Professor S. Rahman,
is looking for new Ph.D. students, who are capable of and interested in performing
high-quality research on reliability-based design optimization.  The research, supported
by NSF and others, entails developing new theory and efficient algorithms for stochastic
computing and design optimization. A solid background in mechanics and elementary
numerical analysis is a must; some exposure to uncertainty and probabilistic methods is
desirable.

If you are interested in pursuing Ph.D. at Iowa, please contact:  Professor S. Rahman at


frequency responce- how to track natural frequency of the beam using Abaqus?

frequency responce- how to track natural frequency of the beam using Abaqus? may i have the example of doing that? and the details that need to be considered.

Thanks.


A funny error

Dear All,I have written a finite element code in C++. The results have generally high accuracy. But when I change the order of evaluating r and theta of the polar coordinates in terms of x and y in the sub-program of computing the shape functions, then the results are changed about 10^-9 of the initial results. The change is negligible but I wonder why this happens? I had initially supposed it may be related to some memory linkage in the program but since now I have not been successful to find any. Is there any one to have an idea about this funny error???


A funny error

Dear All,

I have written a finite element code in C++. The results have generally high accuracy. But when I change the order of evaluating r and theta of the polar coordinates in terms of x and y in the sub-program of computing the shape functions, then the results are changed about 10^-9 of the initial results. The change is negligible but I wonder why this happens? I had initially supposed it may be related to some memory linkage in the program but since now I have not been successful to find any. Is there any one to have an idea about this funny error???


How to mesh sandwich 3D structures

Hello All,

I have some difficulties to mesh the 3D sandwich composite. I want to mesh the outer volume with composite materials  with 15 plies and the inner with foam. I don't know how to do so. I've tried to do mesh the outer volume by SOLID46. But I didn't get good mesh due to element coordinate mismatch. Could anybody please suggest me in this regard? I really need your help.

Thank you very much.

 Wasim  

 


How to mesh sandwich 3D structures

How to mesh sandwich 3D structures
m_meisam's picture

Exprimental Data for Wall or Structure under Blast Loading

Dear guys

I've done some numerical research on behavior of concrete wall under blast loading. And know for checking the validity of my results I need some related exprimental data about it. Is there any one who can help me?

Regards

M.Meisam


Material Properties on Different Elements with Common Node

Hi,

 

I am having a conceptual doubt regarding the following case. Any suggestions are appreciated. We are here assuming linear elastic material.

 

 Let's say I have two bodies with different properties, and they share a common node (as in the attachment). However, I want to perform an analysis without any coupling or contact phenomena. Let's say thermal expansion of the bodies.So while doing the FEA analysis, I can assign the material properties in the element stiffness according to the body elements and solve.

 


Pyramid elements in ABAQUS

Hi every body,


ADINA Support's picture

FSI in Cardiovascular Mechanics

We present an interesting application of ADINA FSI in cardiovascular mechanics, specifically, a potential cause for heart attacks is studied.  Please see     

http://www.adina.com/newsgH63.shtml


Piezo ferroelectric materials

Hello everyone,

I would like to read more about piezo ferroelectric materials  i appreciate if give me some idea regarding application and challengable issues in this subject.

 

Thank you


Azadeh Sheidaei's picture

a paper on continuum damage mechanics

Dear All,

I read this paper “A constitutive model for anisotropic damage in fiber-composites” by Matzenmiller 1995 and I have some questions. I have attached this paper. if anybody read this paper I will appreciate your time to have some discussions.Thanks

Azadeh


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