Some of you probably work on problems that involve moderately large strains. An useful strain measure for such problems in the logarithmic or Hencky strain. In particular, if you deal with the numerics of large strain simulations, you will often need to compute the material time derivatives of logarithmic strains.
Recently I have observed that if I don't perform a routine task for a few months, I tend to forget the steps needed in the process. I have to relearn the process and that's a waste of time. The intention of this blog post is to provide a list of tips for my use which can also be of use to other Linux users. I like free software. Most of the software on this list can be downloaded from SourceForge or some such place.
Professor Graeme Milton will be awarded the 2007 Prager medal from the Society of Engineering Science for his work on solid mechanics. The medal will be handed out at the 44th Annual Technical Meeting of the Society of Engineering Science (SES2007) to be held between October 21 and 24, 2007 at College Station, Texas.
A video that shows how some common couplings work. It's an advertisement but interesting nevertheless. Does anyone know how the Thomson coupling works and what its main drawbacks are? It seems a bit complex and will probably have a higher rate of failure than simpler geometries - but maybe not?
I have attached a copy of my McMat07 talk below. The talk is about a modified mechanical threshold stress (Follansbee-Kocks) model that can be used for strain rates > 1000 /s and high homologous temperatures. In the model, the pressure dependence of the flow stress arises from the pressure dependence of the shear modulus. Even after using the most accurate models for the shear modulus (and the melting temperature) we find that the pressure sensitivity of the flow stress is underestimated by our model (by quite a bit).
Dr. Stewart Silling has provided me with a copy of his talk on Peridynamic theory that he presented at McMat 2007. The PDF file of the talk is attached below.
In order to deal with classical material models and volume constraints, Dr. Silling has modified the original theory to allow for forces that are not necessarily pairwise. A bit on that is included in the talk.
The schedule for the McMat07 session on dynamic behavior and failure is given below. My talk will be an a flow stress model for high strain rates and high temperatures applied to 6061-T6 aluminum alloy. Hope to see youin Austin.
7-2 Dynamic Behavior and Failure of Materials
Topic Chair: Tracy Vogler, Sandia National Laboratories
Topic Co-Chair: Rebecca Brannon, University of Utah