nanoindentation
New methods of analyzing indentation experiments on very thin films
Abstract - Indentation experiments on very thin films are analyzed by employing a rigorous solution to model elastic substrate effects. Two cases are discussed: elastic indentations where film and substrate are anisotropic, and elasto-plastic indentations where significant material pile-up occurs. We demonstrate that the elastic modulus of a thin film can be accurately measured in both cases, even if there is significant elastic mismatch between film and substrate.
This manuscript has been accepted for publication in Journal of Materials Research.
Help needed with interpretation of received P h curves during NANOINDENTATION
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Dear iMechanicas,
I just started doing nanoindentation tests on dry biological samples (wood) with a flat punch tip and I have problems analyzing the results! I would be happy if anybody could give me some suggestions.
While running a test I receive quiet good force-displacement curves (no adhesion, good surface find, no time-depend behavior) but the values for the recieved elastic modulus are not stable! The value scatters over the whole range of displacement.
Trinity College (CRANN) Ph.D. Fellowship: Physics of Nanostructure Forming
Workshop on Probing the Limits of Strength, August 10-12, 2009 at LBL, Berkeley, CA
Dear Colleague:
You are cordially invited to attend a special Workshop on Probing the Limits of Strength, which will be held at Lawrence Berkeley National Laboratory on August 10-12, 2009. This workshop aims to bring together researchers with an interest in experimental and theoretical studies of the fundamental limits of strength in materials. The workshop will include a strong lineup of national and international speakers on advanced mechanical testing techniques and computational materials science of materials deformation at the elastic limit.
PostDoc Position Available at MIT
PostDoc Position Available
Ortiz Laboratory at MIT
Professor Christine Ortiz, Department of Materials Science and Engineering , Massachusetts Institute of Technology, Cambridge, MA, USA
To apply for this position; send cover letter including date available to start, CV, full list of publications, and the names of three references to: cortiz [at] mit.edu (cortiz[at]mit[dot]edu)
Load-displacement curves
I am trying to simualet Indentation Hardness Testing in ABAQUS and feeling like that there is some problem in my model.
Whenever I try to plot load-displacement curves it gives me bumps in the curve. Any idea, what should I do?
Should I reduce mesh size, I have done but then it gives me error with step size and so on.,
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.