When you first start learning finite deformation plasticity, you will run into a plastic flow rate that can be derived from a flow potential such that
| (1) |
whereis the Cauchy stress. For an isotropic material with scalar internal variables, the plastic
flow potential can be assumed to have the form
Nowadays, we often use the tools of computational analysis in engineering design. For the results of such analyses to be believable, the tools that are used have to pass rigorous tests. There are two categories of tests involved:
Recently Henry talked about software that could be used to simulate explosions and introduced CartaBlanca. Luming asked whether anyone had used the software, how good it was, and whether one needed Java to implement models into CartaBlanca.
Terence Tao (one of the Fields Medal winners this year) has started blogging. He has a detailed discussion on the Navier-Stokes equations here. It's long but definitely worth reading - particularly because of the wide range of ideas that he talks about.
A couple of years ago a colleague who wanted to simulate high-speed machining asked me: " Which is the best phenomenological flow stress model for metals?" I wasn't able to give an answer right away and decided to look in the literature.
What I found was, every ten years or so, a new model appears in the literature that tries to solve some of the problems of older models. However, a clear ranking of models has not been established yet.
Update: February 2012
1) The lecture notes are on Wikiversity at http://en.wikiversity.org/wiki/Waves_in_composites_and_metamaterials
2) The book on the topic can be bought from Amazon at http://www.amazon.com/Introduction-Metamaterials-Waves-Composites/dp/1439841578
3) Solutions and errata can be found at node/9727
Last year I spent three months modeling the compressive behavior of aluminum alloy foams. I had hoped to find some evidence of the banding instability that is often observed in elastomeric foams [1]. Lakes writes that this sort of banding instability provides indirect experimental evidence for negative shear modulus [2].