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Three problems about of the shock waves


 Three problems about of the shock waves

                                      for the curious students



                                          The first problem


As it informs in your text-books, for an ideal gas the Hugoniot equation has the form

p[(h+1)V-(h-1)V0]=p0[(h+1)V0-(h-1)V] , h=cp/cv ;

Vikram Gavini's picture

Role of the defect-core in mechanics

Through this post I wish to share some recent results that provide new insights into the role of a defect-core in mechanics. Below is the abstract of the work, and the references and links to the preprints of articles. I look forward to your comments and suggestions.


Arash_Kheradvar's picture

Open Ph.D. Position in Multiscale Cardiac Modeling at University of South Carolina

I have an open Ph.D. position on multiscale modeling of congenital heart disease. Candidates with M.S. or B.S. degree with background in fluid/solid mechanics, material science and applied mathematics with strong academic record are encouraged to apply. The project has both computational and experimental components. Interested candidates may send a CV and name of two references to Further information about my group can be obtained from:

Postdoctoral Fellow in Computational Mechanics

A postdoctoral fellowship is available in the Duke Computational Mechanics Laboratory, beginning in September of 2009 (with flexibility on timing).  Funding for the fellowship concerns research in the simulation of large-scale fragmentation phenomena.  The ideal candidate will have experience in some combination of the following areas:

Wei Hong's picture

Formation of creases on the surfaces of elastomers and gels

When a block of an elastomer is bent, the compressed surface may form a crease. This paper analyzes the critical condition for creasing by comparing the elastic energy in a creased body and that in a smooth body. This difference in energy is expressed by a scaling relation. Critical conditions for creasing are determined for elastomers subject to general loads and gels swelling under constraint. The theoretical results are compared with existing experimental observations.

WaiChing Sun's picture

Spectral decomposition

Dear all,

     Many numerical implementation of plasticity model uses spectral decomposition to represent the Cauchy stress, elastic strain,  such that stress update algorithm is written in the principal directions. As a result, I wonder what makes it benefical to write the stress update algorithm in spectral form? 


WaiChing Sun


NRC Research Fellowship Opportunity at Duke University

Researchers at Duke University are seeking applications for NRC research associates, to work with Professors David Stepp and John Dolbow.  The NRC program is unique in the sense that applicants have the opportunity to perform research on a program they design.  The positions are well-paid fellowships and are nominally for two years, extendable to a third.  

traditional concrete model VS damage concrete model

In my opioion, the traditional concrete model is taking the smeared cracking concept to deal with the tensile cracking and using the elastoplastic method to deal with the compressive softening.

We can find that recently the CDM based concrete model become a hot research subject.

But what are the advantages of the CDM-based?

Thank you very much!

Concrete micromechanical finite element modelling

I could not find a detailed book about micromechanical finite element modelling. There are some books about  micromechanics but They do not consist extensive micromechanical finite element. Could anyone suggest me a detailed book about that?

Numerical phase modeling of BTO nanostructure using Landis' model with FEAP

  The difference to the common model used is the f,g terms. The 3D FEM formulation has been derived and a new fortran program is written. The derivative matrix is symmetric. But the calculation result does not converge. I have tried every means to get a converging result. But it doesn't work, the residual norm always increases.

Differences of various strain measures

For large deformation, we have various deformation measures such as Green-Lagrange tensor, Almansi strain tensor, left Cauchy-Green deformation tensor, and right Cauchy-Green deformation tensor. Appreciate very much any explanation in respect to physical differences of those measures, why they are necessary, conditions where one is more accurate than another! Thank you.


Viscoelastic Abaqus Analysis question please help

Hi Everyone,

I am new to thermal viscosity analysis, here is the data I have received.


DMA data which has Temp, Shear Storage Modules, Shear Loss Modules,  Tan Delta, Calculated Modules, Temp was raised at 5 deg/Min

I want to do a thermal analysis where the part is heated upto 90 deg for 1 hr, returned to room temp and cooled 2 hours.

 How can i simulate this in abaqus ..? I want to incorporate the Viscosity data from the DMA data. I also have received  thermal conductivity, thermal expansion and specific heat data.'s picture

Post-doctoral Position in Multiscale Modeling at Caltech

The Center for the Predictive Modeling and Simulation of High-Energy Density Dynamic Response at the California Institute of Technology seeks a post-doctoral scholars in the broad area of multiscale modeling of materials.  The scholar will be supervised by Professor Kaushik Bhattacharya, and will develop fast multiscale models that implicitly account for the microstructural features during the dynamic deformation of materials.

Stress-induced phase transformation and pseudo-elastic/pseudo-plastic recovery in intermetallic Ni–Al nanowires

Dear friends,

I want to share our recent research work on NiAl nanowire, which is published in Nanotechnology, IOP publishing. The abstract of the paper is given below. Further details can be found at "Vijay Kumar Sutrakar et al 2009 Nanotechnology 20 295705 (9pp)   doi: 10.1088/0957-4484/20/29/295705"


Wei Hong's picture

Large deformation and electrochemistry of polyelectrolyte gels

Immersed in an ionic solution, a network of polyelectrolyte polymers imbibes the solution and swells, resulting in a polyelectrolyte gel. The swelling is reversible, and is regulated by ionic concentrations, mechanical forces, and electric potentials. This paper develops a field theory to couple large deformation and electrochemistry. A specific material model is described, including the effects of stretching the network, mixing the polymers with the solvent and ions, and polarizing the gel.

Characterising fracture toughness in epoxy using mechanical fatigue. Help!

Hi all,

I have taken up this research project/attachment on
"characterising the fracture toughness of epoxy using mechanical
fatigue", and encountered lot's of problems while researching. I'm just
a student, not even in university, but rather still schooling (grade
10), so am completely new to this field, which explains my problem in
understanding all the lit reviews, lecture slides i found online.
Luckily, i found out this site, and would hope that someone can guide
me in the right direction!

2009 ASME Applied Mechanics Awards

Congratulations to the winners of the 2009 Awards:

EMI 2010 Engineering Mechanics Conference at USC, Los Angeles California, August 8-11, 2010

EMI, the Engineering Mechanics Institute of ASCE, will hold its annual conference on August 8-11, 2010 at the University of Southern California in Los Angeles, CA.   Dr. Roger Ghanem (Department of Aerospace & Mechanical Engineering) and Dr. Amy Rechenmacher (Department of Civil and Environmental Engineering) will be the Co-chairs of the EMI 2010 Conference.

Zanaboni Theorem Is Not True

Zanaboni  Theorem  Is  Not  True

Dynamic Modeling for Viscoelastic material using ANSYS


I am planing to model a viscolestic material in ANSYS and condition is dynamic.

Could anyone please suggest what are the essential things (i mean datas) required for modeling a viscoelastic material?

For example, If I do the DMA test of viscoelastic materials i can have the modulus data at different frequencies. How to use those data in ANSYS to find out the stress-strain curve?

Thnaks for your kind help

parimal maity


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Dear professors

 Could you please help me to get an MATLAB code for non linear analysis of simply supported beams please.

Email me on;

Best regards


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