Plasticity

The Change of Microstructure at low temperature

Submitted by Shaomin Xiong on Sat, 10/04/2008 - 06:42

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Recently, we do some work about the dynamic strain aging. In order to investigate the function of solute clouds and precipitates in DSA, we do some experiments. The solution treated LY12 alloys are tested on MTS at low temperature (173K), and the Portevin-Le Chatelier phenomenon disappeared as we expected. But, we need more information about the change of microstructure under the low temperature, what is more the micro-optical observation should be finished in a very short time when we consider the effect of natural aging. Obviously the TEM can not meet our needs.

Postdoctoral Appointee – Computational Plasticity

Submitted by James Foulk on Fri, 08/29/2008 - 04:54

A postdoctoral position at Sandia National Labs in Livermore, CA is available for an applied mechanics engineer with a strong background in computational constitutive model development. The work will support our current projects in the areas of continuum plasticity and failure modeling. The applicant will also be expected to implement models into Sandia computer codes for high-performance computing simulations. In addition, the candidate will collaborate with structural analysts to apply these advanced models to Sandia applications.

Could anyone help on Drucker-Prager model?

Submitted by Botao on Wed, 08/20/2008 - 09:44

research

Plasticity

Drucker Prager model

I am using exponent Drucker-Prager model at the moment, is there anyone can tell me where the follow exponent D-P eqation comes from originally?

(σ e)(σ e)=λ(σ_t)(σ_t)-3(λ-1)σ_mσ_t

Where λ= is hydrostatic stress sensitivity parameter and equal to σ_c/σ_t, σe is effective stress, σ_m is hydrostatic stress, σ_c, σ_tare stresses under compression and tension, respectively.

Postdoctoral position in Computational Solid Mechanics - School Of Mechanical Engineering Purdue University

Submitted by marisolkoslowski on Tue, 08/19/2008 - 13:32

A postdoctoral position is available starting Fall 2008 in the area of computational solid mechanics. A successful candidate is expected to have a strong background in multiscale modeling and programming experience. While experience in plasticity using finite element methods or dislocation dynamics is a plus , all outstanding candidates will be considered.

Journal Club Theme of July 15 2008: Plasticity at Sub-Micron Scales

Submitted by Cai Wei on Tue, 07/15/2008 - 02:11

research

Plasticity

size effect

Research on the plasticity/damage coupling model using continuum damage mechanics

Submitted by pfliu@zju.edu.cn on Sat, 07/12/2008 - 13:16

research

Plasticity

damage

Currently, i am now attempting to establish a plasticity/damage coupling model using continuum damage mechanics for complex metal structures such as steel pressure vessel, which can be implemented using finite element analysis. The model can predict the progressive failure and damage evolution as well as the crack initiation and propogation due to large plastic deformation of metal structures. Who can give me some suggestion or idea?

Time dependent vs Independent

Submitted by HariKrishna on Wed, 06/11/2008 - 14:33

research

computational mechanics

Plasticity

creep

In Computational mechanics, for rate(time) dependent calculations (eg. Creep, plasticity), when we say time step dt, does it mean physical time.

Can I think this way:

I start at time 0 and calculate stress, strain etc after 1 sec, 2 sec, 3 sec..

Also, what exactly is strain rate? why do some books say ..'when a strain rate is applied'''..I'm confused..dont we just apply displacement or force all the time.