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. The methodology is demonstrated for both compliant films on stiff substrates and the reverse combination and shows improved accuracy over previous methods. 

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

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. http://www.springerlink.com/content/102932/

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

 Thank you.

Qiang Lu and Rui Huang

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

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?

Himayat

POSITION: POSTDOCTORAL RESEARCH FELLOW AT THE UNIVERSITY
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 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

Room: Fairfax A/B, Sheraton Boston Hotel & Towers, 39 Dalton Street, Boston, MA, Phone:  617-236-6039

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.

For more details and to apply see https://recruitment.csiro.au/asp/Job_Details.asp?RefNo=2008%2F1211

I would invite you to present your research work at the Society of Experimental Mechanics Conference (visit www.sem.org  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.

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

Thanks 

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 cipolla@wai.com for inquiries and details.

I am doing contact simulation of soft material. I want to change the default criterion for max penetration error, but can't seem to find how to do it. I tried contact controls relative and absolute penetration tolerances, hcrit but that did not affect the error criterion. Can someone help me please?

F. X. Xin, T. J. Lu & C. Q. Chen
 MOE Key Laboratory for Strength and Vibration, School of Aerospace, Xi’an Jiaotong University, Xi’an, 710049, P.R. China

I am a M.s student of aerospace engineering.my thesis title is: cracked beam vibration with finite element method ,I have done literature review about this subject.they are many papers about this subject.and I want to works new topics with this subject.please help me and send your advise about new topics with this subject.

Save the date for SBC2009!

ASME Bioengineering Division's upcoming annual Summer Bioengineering Conference (SBC2009) will be held between June 17-21, 2009 in the spectacular Squaw Creek Resort, a majestic setting at the base of the mountain and minutes from the natural wonder of Lake Tahoe (www.squawcreek.com ). An outstanding scientific program is being planned, including Plenary Lectures, Symposia, Workshops, and Student Competitions. Abstracts are due January 15th, 2009. The emerging program, plenary speakers and call for papers can be accessed at the conference website:

Hello Everyone

Cycle counting is used to summarize (often lengthy) irregular load-versus-time histories by providing the number of times cycles of various sizes occur. The definition of a cycle varies with the method of cycle counting. ASTM E1049 cover the procedures used to obtain cycle counts by various methods, including level-crossing counting, peak counting, simple-range counting, range-pair counting, and rainflow counting. Cycle counts can be made for time histories of force, stress, strain, torque, acceleration, deflection, or other loading parameters of interest.

Hello Everyone,

I am Md. Zahidul Mustakim from Bangladesh. I have graduated in Mechanical Engineering and I want to pursue my Master's Study in the field of Computational Engineering/Mechanics. As i was not familiar with this field in my undergrad study I really dont know much about this subject. I would be really grateful if You please send me some informations about the points mentioned bellow:

1. Is computational Engineering same as Numerical Simulation?

2. Wht are the areas of Mechanical engineering where computational engineering techniques are being used?

Searching for a Ph.D Student in Applied Mechanics Area, especially in constitutive modeling of piezoelectric fiber composites.

Excellence in ABAQUS, Fortran, MATLAB is required. Send an Email to jhkim@engr.uconn.edu with this title "reply to job posting in imechanica".

For several common electroplated materials: Ni, Cu, Au and Al, which one has strongest fatigue strength? We know the mechanical properties of thin films are different with their bulk counterparts due to the so called "size effect", and material properties depends largely on the microstructure and processing technique. But is there some mateiral laws or guidelines for designers to choose the "best material" as for fatigue resistant? Yield limit? ultimate tensile strength? or elongation? How could one compare material candidates without doing time-consuming test?

We know that total strain is the symmetric part of the displacement gradient. Total strain can be represented by the sum of the elastic and plastic (eigen) strains. Let consider a dislocation in an arbitrary solid. Suppose we computed the displacement filed, therefore the total strain can be obtained immediately. What are the criteria for the decomposition of the total strain into elastic and plastic parts?

Applications are invited for full-time, continuing academic positions in a number of areas in the Department of Mechanical Engineering, Curtin University Sarawak.

Please see website for information : www.curtin.edu.my