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Active Materials for Medical Devices

In conjunction with the 2nd International Joint Conference on Biomedical Engineering Systems and Technologies - BIOSTEC 2009


mesh refinement for eigen-properties of a cracked body

 It is a common technique in modelling cracked bodies with finite element method, to refine the mesh near the crack tip. It is mentioned in text books, mesh refinement is nessecary to increase the acuuracy of the computed stress intensity factor for the crack tip. Is meshrefinement nessecary for computing eigen-properties ( natural frequencies and natural modes ) as well as SIF? or eigen properties are not affected much by the near crack tip field?

An Elastic Plate Problem

It would be very helpful for me if somebody clarifies the following problem: Suppose a beam with simply-supported boundary condition is loaded by uniformly distributed load. One can find out the moment and shear force at any point on the beam by finding forces at the boundaries and then considering equilibrium of some section of the beam.

ramdas chennamsetti's picture

Why rate equations in Nonlinear FE?

Hi all!

I have a very fundamental question as follwing.

In Nonlinear FE formulations, we use rate equations (virtual work), but, in linear FE we don't use rate equations. Why???

Is it because Nonlinear solution is iterative solution (time may be virtual time).

I request those who have an idea to give some explanations.

Thanks in advance,


- Ramdas


Automobile engineering

can anyone give me the address of the best website about car where i can find everything about car--engine, transmission, ignition..... everything, from basic to advanced knowledge, from old to new technologies. free or paid site.

Yuri Estrin's picture

Postdoctoral Fellowship at CSIRO, Melbourne, Australia


Applications are invited for an OCE Postdoctoral Fellowship in the research area "Local Property Enhancement in Light Alloys". The appoitment, for a period of three years. will be with the Light Metals Flagship and CSIRO Division of Materials Science and Engineering.

D.Rittel's picture

Adiabatic shear banding

The subject of adiabatic shear banding is quite classical and the main assumption is that it consists of  structural/mechanical instability in which the thermal softening effects play a dominant role in the generation of the band (Zener-Hollomon).

I would like to focus on the phase that precedes global failure, namely up to the peak stress or strain) at which the material starts to exhibit negative strain hardening.

A TEM postdoc position is available at Sandia National Lab.

Job Description: The CINT Science Department is searching for a postdoctoral appointee to pursue research in the area of leading-edge electron microscopy of nanomaterials and their properties. The successful candidate will work closely with the staff scientist heading electron microscopy research activities at CINT on topics related to the structural, mechanical, thermal, and electrical properties of modern nanomaterials.

Journal Club Forum for October 15th: Experimental Solid Mechanics at the Nanoscale

Browsing through past themes, I realize that this is the third time the topic of experimental mechanics at the nanoscale has been highlighted in the jClub forum. There are many problems that require experimental research at the nanoscale that we can do this a few more times without being repetitive. I would like to focus this discussion on the fundamental issue of friction.

Faculty Position in Sustainable Material Synthesis and Characterization at the University of Pittsburgh

The Department of Civil and Environmental Engineering at the University of Pittsburgh invites applications for a faculty position effective September 1, 2009. The search is open to all ranks depending on qualifications and experience. 

Li Han's picture

Determining the elastic modulus and hardness of an ultra-thin film on a substrate using nanoindentation

Abstract – A data analysis procedure has been developed to estimate the contact area in an elasto-plastic indentation of a thin film bonded to a substrate. The procedure can be used to derive the elastic modulus and hardness of the film from the indentation load, displacement, and contact stiffness data at indentation depths that are a significant fraction of the film thickness. The analysis is based on Yu’s elastic solution for the contact of a rigid conical punch on a layered half-space and uses an approach similar to the Oliver-Pharr method for bulk materials.

Teng Li's picture

iMechanica: 9000 registered users, 30,000,000+ web hits

The number of registered users of iMechanica reached 9000 on 13 October 2008, after two years and one month since the website launch. The total number of posts is 4036, the total number of comments is 8888, and the total web hits is estimated to be more than 30,000,000.

Hosted at Harvard School of Engineering and Applied Science and maintained by a growing number of volunteers, iMechanica aims

David J Unger's picture

J-Integral Elliptical Hole (Plane Stress) Perfectly Plastic Material

Choose a channel featured in the header of iMechanica: 

The fracture mechanics community may be interested in a new evaluation of a J-Integral for a fundamental geometry:  an elliptical hole in a perfectly plastic material under the Tresca yield condition for plane stress loading conditions. The analysis is exact and involves only elementary functions.  This makes the problem suitable as a classroom example or as a homework problem for a graduate level course in fracture mechanics.  See J. Elasticity (2008) 92:217-226.

Shear Locking vs. Membrane Locking?

Could anyone briefly explain what is the difference between "Shear Locking" and "Membrane Locking". Does this apply to plain strain elements?

 Thank you.

Nonlinear mechanics of single-atomic-layer graphene sheets

Qiang Lu and Rui Huang

Department of Aerospace Engineering and Engineering mechanics, University of Texas, Austin,
TX 78712, USA

Post Buckling of Thin Shells

It is difficult to conduct post buckling analysis of thin shell under axial compression using Arc Length method in Ansys.
The Minimum & Maximum Arc Length radii are chosen by hit & trial.When imperfections are incorporated in the FE model,  some times the solution diverges at a higher critical load that the eigen value  buckling, which should be vice versa in actual. Some times , negative eigen values are also shown.

Is there any easy way to solve this nonlinear stability problem?


Position: Post-doc at the Univ. of Auckland, New Zealand

Project Title: Advanced Modelling and Simulation of Closed Mould
Composite Manufacturing Processes
Applications are invited for a postdoctoral research position on composite manufacturing processes with the Liquid Composite Moulding (LCM) Group at the University of Auckland. The successful candidate will play a major role in developing the LCM group’s research into advanced composites manufacturing processes (including I/CM, Resin Infusion, VARTM, and RTMLight).

You are cordially invited to attend a reception in honor of Professor John W. Hutchinson

John W. HutchinsonYou are cordially invited to attend a reception in honor of Professor John W. Hutchinson during the ASME International Mechanical Engineering Congress & Exposition.  Download a printable version of this invitation.

Monday, 3 November 2008, 7:30 pm to 9:30 pm

Andrew Bunger's picture

Postdoctoral Fellowship studying mechanics of hydraulic fracturing for stimulation of hot fractured rock geothermal reservoirs

CSIRO Petroleum in Melbourne, Australia, welcomes applications to a Postdoctoral Fellowship
in hydraulic fracture stimulation mechanics. The successful candidate
will have a background in applied mechanics and numerical methods with
an interest in verifying numerical calculations by experiment.  The
research results will be applied to stimulation of hot fractured rock
geothermal reservoirs.

Luoyu Roy Xu's picture

2009 SEM conference in Albuquerque, New Mexico USA

I would invite you to present your research work at the Society of Experimental Mechanics Conference (visit  for more details). You are welcome to submit your abstract my two sessions: 

1. Mechanical Behavior of Nanocomposite Materials

2. Recent Advance in Composite Materials.

Theoretical and Experimental Studies of Bending of Inorganic Electronic Materials on Plastic Substrates

In this paper, we report comprehensive experimental and theoretical
studies of bending in structures relevant to inorganic flexible electronics.
Different from previous mechanics models of related systems, our analysis does not
assume the thin film to cover the entire substrate, thereby explicitly
accounting for effects of edges and finite device sizes, both of which play
critically important roles in the mechanics and bending properties. These
thin-film islands give nonuniform stress, with maxima that often appear at the
edges and spatially non-uniform shear and normal stresses along the film/substrate
interface. Although these results are generally applicable to all classes of


I am student of mechanical engineering at the Australian National University.I am trying to investigate if there is any The Nanotechnology has any impact on Finite Element Analysis(Method) in term of nanoscale


Seeking US citizen MS/PhD applicants with computational mechanics background

Hello - trying AGAIN to get this to post. I'm seeking applicants with computational mechanics background for new work in security applications. Areas include blast, failure, acoustics, and related fields. Security requirements dictate that we must have US citizens for this work - sorry, I know that's restrictive. Please feel free to email me at for inquiries and details.


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