Blog posts

Revisiting pyramid compression to quantify flexoelectricity: A three-dimensional simulation study

Submitted by Amir Abdollahi on Tue, 03/03/2015 - 15:43

Flexoelectricity is a universal property of all dielectrics by which they generate a voltage in response to an inhomogeneous deformation. One of the controversial issues in this field concerns the magnitude of flexoelectric coefficients measured experimentally, which greatly exceed theoretical estimates. Furthermore, there is a broad scatter amongst experimental measurements. The truncated pyramid compression method is one of the common setups to quantify flexoelectricity, the interpretation of which relies on simplified analytical equations to estimate strain gradients.

Contact problem

Submitted by DRIDIAFEF on Tue, 03/03/2015 - 13:49

hyperelasticity

Hello

Iam trying to model an orthodontic apparatus movement. Can anyone help me how to choose the type of interaction between the three parts. In attached the assembly. THE steps are : the ring will be opened then it will descend finally the ring will return to its initial position can anyone tell me how to choose interaction properties. Thanksa lot

ABAQUS error

Submitted by Navid Moheb on Mon, 03/02/2015 - 21:38

Hello everyone,

I am modelling a three dimensional cohesive element problem with Abaqus. I was wondering to see if anyone had the following error in their analysis:

THE NODE NUMBERING MIGHT NOT BE CORRECT FOR ELEMENT *** INSTANCE ***

Fifth Biennial Workshop on Direct Methods

Submitted by acfcocks on Mon, 03/02/2015 - 17:27

The fifth biennial workshop on 'Direct Methods' will be held in Oxford, UK on 6^th to 8^th September 2015. It follows on from previous successful workshops held in Aachen, Lille, Athens and Reggio Calabria (see http://www.iadime.unirc.it/ ).

Fifth biennial workshop on Direct Methods

Submitted by acfcocks on Mon, 03/02/2015 - 17:25

3D FEA of stress concentration

Submitted by setareh on Mon, 03/02/2015 - 12:26

research

stress concentration

FEA

Dear all,

I am simulating tensile specimens with an elliptical pore(representing a flaw in the material) in the mid-cross section of the specimen. What I am looking for is the stress concentration caused by this pore.

I am simulating this as a 3D specimen under tensile loading only, with 3D, 8-node linear brick elements(1st order). Now my questions are:

1- Is there any analytical solution for such problems(3D with elliptical pore) with which I can compare my FEA results?

Two PhD positions available at the Department of Petroleum Engineering, Texas A&M University

Submitted by sabedi on Mon, 03/02/2015 - 04:03

job

<p>Two PhD positions are available at the Department of Petroleum Engineering, Texas A&M University in the area of characterization and micromechanical modeling of organic-rich shales. Candidates should have a BS or MS degree in civil engineering, mechanical engineering, petroleum engineering, material science or other related areas. Candidates with background in experimental and modeling of porous materials are highly preferred.

Characteristic impedance of a tube

Submitted by BMEstudent on Sun, 03/01/2015 - 22:42

characteristic impedance

acoustics

standing waves

Hi all,

I need to calculate the characteristic (or specific) impedance of a tube. Generally this tube has a varing cross-sectional area (diameter changes and it has tube is not cylidrical). However for a very simplified case, let's assume it is a perfect cylender terminated at a finite length. The walls and termination are not rigid so it will have interaction with acoustic pressure inside.