Blog posts

Elastic Material Constants Question

Submitted by ahmed.hussein on Sun, 06/06/2010 - 20:55

I have a very basic question regarding anisotropic materials elastic constants.

The elastic constants must satisfy the condition of the positive definiteness of the stiffness matrix so that the strain energy is guaranteed to be positive for any strain state. However, are there any extra conditions on these constants ?

In particular, can we have a material with shear stiffness higher than the normal stiffness even if the stiffness matrix is still positive definite ?

If so, is there any physical explanation, on the microlevel or something, for this phenomenon ?

Simulation of simple compression of a cylinder between two plates using ABAQUS

Submitted by Manjesh on Sun, 06/06/2010 - 17:46

Hi,

I need to simulate a simple compression process. I want to know what kind of boundary conditions i have to give. I have tried giving displacement to the end plates or applying some uniform pressure at the end plates but I am not getting the expected pressure distribution at the contact. Plz somebody suggest me what to do???

PhD Research Positions in Computational Nanomechanics at the University of Pittsburgh

Submitted by MKirca on Sun, 06/06/2010 - 14:30

job

nanomechanics

computational mechanics

Several PhD research positions are currently open in the Computational Nanomechanics Group at the University of Pittsburgh for the following research projects:

1. Thermomechanical behavior of carbon-based nanomaterials

2. Atomistic-to-continuum themomechanical theory in solids

3. Mechanics of nanoporous and nanocrystalline metals

ARC and CRC APAI PhD Scholarships in Rail Engineering

Submitted by Sakdirat Kaewunruen on Sun, 06/06/2010 - 13:48

ARC and CRC APAI PhD Scholarships in Rail Engineering

Acoustics Finite Element

Submitted by avicina on Sun, 06/06/2010 - 11:57

I want to model a building acoustic problem in a FEM software like Ansys or Abaqus.

which of the FEM softwares are more convenient for modeling of this problem, (I mean FEM acoustics.)

thx.

Research Positions Available UCLA Fusion Science & Technology Center

Submitted by uclafusion on Fri, 06/04/2010 - 21:26

job

The UCLA Fusion Science & Technology Center is seeking to fill several research staff positions to perform research in areas that include CFD, heat and mass transport, chemical processes, and/or structural mechanics. Research positions are available for beginning and mid-career levels.

Candidates should have a PhD degree in mechanical, nuclear, or chemical engineering with strong background in analysis, modeling, numerical computation, and/or experimental techniques. The research applications are in the area of fusion nuclear science and technology.

hi

Submitted by ABAqirl on Fri, 06/04/2010 - 15:44

test

A great russian mathematician Vladimir Arnold died on 3rd of June, 2010 in Paris

Submitted by gregk on Fri, 06/04/2010 - 12:40

mechanician

Arnold

mathematician

Vladimir Arnold died on 3rd of June 2010 in Paris, just 9 days before his 73rd birthday.

I am sure many mechanicians know him by his books, such as

Mohr's Circle---When Was the Last Time You Used It in Your Professional Engineering Work?

Submitted by Ajit R. Jadhav on Thu, 06/03/2010 - 17:01

Professional Engineering

As a consultant in computational mechanics, I currently help write some FEM-related code, and while doing this job, an episode from a recent past came to my mind. Let me go right on to the technical issue, keeping aside the (not so good) particulars of that episode. (In case you are curious: it happened outside of my current job, during a job interview.)

If you are a design engineer, FE analyst, researcher, or any professional dealing with stress analysis in your work, I seek answers to a couple of questions from you:

Question 1: