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Xueming Shao's picture

In Chinese:浙江大学流体力学学科诚聘国内外优秀人才

    浙江大学流体工程研究所因学科发展的需要,面向国内外公开招聘流体力学、空气动力学、流体机械等相关领域的教授、副教授、讲师和博士后,竭诚欢迎海内外优秀人才加盟。

sg's picture

Polyethylene Foam Damping Coefficient

Hi,

I am doing drop test simulation in Ls-Dyna for a transport system consisting of polyethylene foam as cushioning material. Does anybody know damping coefficient value levels for LDPE (Low density polyethylene) foam materials in the range of density of 30-80 kg/m3. 

Thanks in advance

Serdar

S. Beretta's picture

Research assistant and PhD position at PoliMi on micro-plasticity models

In the last decade, different
cyclic plasticity models
, based on the “continuum” approach, have been proposed
in order to account for different mechanical effects (such as ratchetting,
strain range dependence, non-proportional loading and memory effect), [1, 2]. A
disadvantage of this approach is the elevated number of model parameters
introduced in order to correctly predict the material behaviour. The determination
of these parameters, usually difficult and expensive,
is one of the reasons why the modern
constitutive models are not widely used in finite element simulations of

Helmut Boehm's picture

Positions for doctoral students at TU Wien

There are two open positions for doctoral students at the Institiute of Lightweight Design and Structural Biomechanics  (ILSB) of Vienna University of Technology (TU Wien), Vienna, Austria

    * A part-time research/teaching assistant in lightweight structures and numerical methods

    * A full-time project assistant in composite mechanics

Post Doc position at ETH Zurich in computational structural mechanics

The Laboratory of Thermodynamics in Emerging Technologies (LTNT) at ETH Zurich has an opening for a

Post Doc

Area
Computational structural mechanics with focus on soft tissues and wave propagation

Haitao Zhang's picture

Internship available in FEA of crack growth

Title: Structural FEA Intern 

Employer: Schlumberger Technology Corporation

Location: Sugar Land, TX, USA

Starting Date: 01/01/2011 

S. Beretta's picture

Research assistant and PhD position at PoliMi on corrosion-fatigue

Raiway axle failures have been the starting point for the studies on fatigue. However, recent accidents and papers (see [1] by Hoddinott) have shown that corrosion-fatigue plays a significant role.

At PoliMi we have recently investigated this topic finding interesting results by corrosion-fatigue tests on small-scale specimens and, recently, a validation of the model by full-scale corrosion-fatigue tests (see papers [2-3]).

Postdoc position available on atomistic simulations of water/graphene interface

A postdoc position is available next January at Research Center for Applied Sciences, Academia Sinica in Taiwan on the molecular simulation of the water/graphene interface.

For those who are interested, please contact Chun-Wei Pao (cwpao@gate.sinica.edu.tw) or Jer-Lai Kuo (jlkuo@pubs.iams.sinica.edu.tw).

 

Record of ANSYS - IOSO Robust Optimization for CFD Webinar

Dear Colleagues,

The official version of ANSYS - IOSO RDO for CFD Webinar record is available: http://www1.ansys.com/customer/publi...=yes&agenda=no

After the filling the form you can immediately start watching.

Speech of Acceptance of the 2010 Timoshenko Medal by Wolfgang G. Knauss

files/knauss-w72_2.jpgIn the following the italicized portions were stricken from the oral presentation to better approximate the time length suggested. They are retained here primarily for the preservation of historical developments in mechanics.

Experimental Mechanics of History

How to determine crack length in XFEM analysis

Hi guys,

i am doing crack propagation analysis using XFEM. My model is working fine. i want to know how one can determine the length of the propagated crack against time increment. Is there any built in histroy out put variable with which one can calculate the length of the propagated crack using histroy output or is there any other way for example using pyton scripting. would be my pleasure to hear valuable comments from you guys. 

Alex

Can microscopic coefficients always be derived from macroscopic coefficient (biot effective coefficient, skempton coefficient)?

Can microscopic coefficients always be derived from macroscopic coefficient?

To be more specific, 

alpha: Biot-Willis coefficient, Skempton coefficient 

These two parameters are derived from the macroscopic level which reflects the response of a porous material as a whole, without explicitly taking into account the individual contribution of its solid and fluid constituents.

From microscopic level, there are parameters (or bulk modulus) such as Ks (solid grain bulk modulus), Kf (fluid bulk modulus), and porosity. 

beginner of MD/DD. what are all the topics that need to be covered?

Dear iMechanica memebers,

I am a PhD student. I started to work on MD and DD. I know the overview of the  MD and DD,but to have the good basics (statistical mechanics, quantum mechanics, classical mechanics and dislocation dynamics ) knowledge,  i am not getting where to start and where to end these subjects.

could any one tell which are the main topics to be covered in the above subjects, if possible could any one suggest good books related to these subjects. 

could any one please help me in this regard.

 with best regards

kiran 

Create geological fault using Abaqus CAE

Hi I am new to modeling. I am currently using Abaqus to do a model on basin inversion. However, I have never done modeling or any similar thing, I don't quite know how to produce a final model with an initial model that has no fault, just nothing.

If anyone can please help me on this, I would like to start with simple models which is a model with graben horst and a model with thrust fans. These models are to be in their cross section (not 3D models). Detailed information is much appreciated.

Joyce

anishiitk's picture

Analytical buckled mode shapes of ring

Hi,

I am facing problem in finding the analytical exact buckling mode shapes
for ring. I have already found buckled shapes through ABAQUS, and now I
am trying to find the buckled shape through some analytical equation.
If anybody has some idea about it, so please let me know. Can it posible
to get the exact analytical equation for buckled shape of ring which
approximate match with ABAQUS result.

Anish Kumar

M.Tech. (Solid Mechanics and Design)

Mechanical engineering department

IIT Kanpur, India.

Book request...

Dear all,

I am searching for the following book:

"Some basic problems of the mathematical theory of elasticity" by Nikolai Ivanovich Muskhelishvili.

If somebody has a softcopy I would appreciate it if he sent it to me. If someone has a hardcopy and can lend it to me for a few days, I would be grateful...

Thanks in advance,

George Papazafeiropoulos

anishiitk's picture

Analytical buckled mode shapes of ring

Hi,

I am facing problem in finding the analytical exact buckling mode shapes for ring. I have already found buckled shapes through ABAQUS, and now I am trying to find the buckled shape through some analytical equation. If anybody has some idea about it, so please let me know. Can it posible to get the exact analytical equation for buckled shape of ring which approximate match with ABAQUS result.

Anish Kumar

M.Tech. (Solid Mechanics and Design)

Mechanical engineering department

IIT Kanpur, India.

arash_yavari's picture

Effect of External Normal and Parallel Electric Fields on 180^o Ferroelectric Domain Walls in PbTiO3

We impose uniform electric fields both parallel and normal to 180^o ferroelectric domain walls in PbTiO3 and obtain the equilibrium structures using the method of anharmonic lattice statics. In addition to Ti-centered and Pb-centered perfect domain walls, we also consider Ti-centered domain walls with oxygen vacancies. We observe that electric field can increase the thickness of the domain wall considerably. We also observe that increasing the magnitude of electric field we reach a critical electric field E^c; for E > E^c there is no local equilibrium configuration.

kapornith's picture

mechanics problem Dahl and Crandall

Hi All,

I am doing a problem on mechanics and find that the answers are not matching (mine are coming .0085 and .002 inch).I am attaching the question and the answer herewith.

I presume that bending effect is not to be taken into consideration as otherwise the dimensions of the beam would have been furnished.I tried both direct stiffness and virtual work methods and didn't get the required answer.

Can anybody validate the same.I restrain myself using FEA analysis fo it as it would have taken thet bending effect also.

Thanks and Best Regards

Help!!VUMAT Abaqus 6.10-1 ERROR LINK

Hi there,

I'm a new member of imechanica; I'm using Abaqus 6.10-1/Explicit to analyze the impact of a rigid ball onto a composite plate. I installed fortran compiler ifort 11.1. I'm using VUMAT subroutine (material model is based on Hashin's failure criteria).

This is my Abaqus_v6.env file:

compile_fortran=['ifort', '/c' , '/Gm', '/recursive', '/nologo', '/heap-arrays:1', '/include:%I']

link_sl='cmd /c "LINK /nologo /INCREMENTAL:NO /subsystem:console /machine:X86 /NODEFAULTLIB:LIBC.LIB /NODEFAULTLIB:LIBCMT.LIB /DEFAULTLIB:OLDNAMES.LIB

mpeleehp's picture

Research Fellow/Research Assistant positions for mechanism design/vibration analysis of actuators for 10 Tbits/square HD Drives

Our group has two research openings for people with expertise on mechanism design / dynamic and vibration analysis of actuators cater to 10 Tbits/square inch hard disk drives. Please send your cv to me at mpeleehp@nus.edu.sg or Prof Ong CJ at mpeongcj@nus.edu.sg.

mpeleehp's picture

Newton’s laws and a dynamic force-field analogy for analyzing organizational changes

The abstract of the paper is as follows (to appear in International Journal of Mechanical Engineering Education)

 A dynamic force-field analogy for analyzing organizational change is presented. Instead of

just analyzing the driving and restraining forces in the traditional force-field analysis, which is similar to

the static analysis in solid mechanics, the forces opposing change can be modeled in terms of viscous

or frictional forces that may be encountered. Some analogies between organizational change and the

felipecardenas's picture

The limits of economy of material in frame-structures (Michell, 1904)

Somebody have the Michell's work about structural optimization??: The limits of economy of material in frame-structures. Please. I need it....if you can send it to me...please contact me. Thanks

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