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Three postdoctoral positions at Lawrence Livermore National Laboratory

Submitted by Scott Johnson on

The Computational Physics group in the Atmospheric, Earth, and Energy Division at the Lawrence Livermore National Laboratory (LLNL) is solicitating applications for three postdoctoral appointments in the following areas. To access the full description and application instructions, please visit http://jobs.llnl.gov and search for the job numbers below:

008351: geomechanics of fluid-induced fault activation

008374: dynamic impacts into granular materials

008375: mechanics of dynamic impact and penetration into ceramics

FRANC3D - the next generation

Submitted by bjc21 on

I guess it is about time some one from the Cornell Fracture Group got on this site to try help answer questions related to the CFG software or other fracture mechanics related questions.  We do try to answer questions sent to us via email, but sometimes a forum like this would be best and we do appreciate other users input, feedback, and answers.

President Obama on the Necessity of Science (video)

Submitted by Teng Li on

Obama spoke at the National Academy of Sciences on Apr. 27, 2009, in which he states his commitment to doubling of science funding and stem education. From his speech,

 "At such a difficult moment, there are those who say we cannot afford to invest in science, that support for research is somehow a luxury at moments defined by necessities.  I fundamentally disagree.  Science is more essential for our prosperity, our security, our health, our environment and our quality of life than it has ever been before."

drilling simulation abaqus 6.7

Submitted by Sameer_Shah on

hi...i am doing drilling simulation on abaqus.... 



it consist of two parts...a tool and a blank.... 



now when i am running analysis...tool touches the blank and goes back. 



i checked material data...density,elasticity...and i used surface to surface interaction with penalty as interaction property.... 



can any one tell me ...how to perform this.... 

VUMAT debuging

Submitted by hitjgliu on

Hi all

   I am a new ABAQUS VUMAT user. Recently, I try to substitute the explicit intergation method in VUMAT by back EULER intergation method. But the calculated equivalent stress is nonuniform for simple compression test. Would anyone pls help me find the reasons? Many thanks. Attached pls find the VUMAT subroutine and INP file.

 

 J.G. Liu

Ph.D

HK Polyu

Using Abaqus for cracks in the rocks

Submitted by Diana W.Smith on

Hello Everyone,

 My research is in petroleum geomechanics and I am Using Abaqus for my simulations of cracks and induced fractures in rocks around the wellbore I do have some problms and I will be happy if anybody can assist me:

1- I am interested in looking at Hoop stress at evry point around the wellbore ,but in Abaqus I can only see that in degrees of 0,90,180,270 of circular wellbore by using S1 and S2 ,naybody has a code or experience with that?

2-What is a correct method if we are interested in propping our fractures?

High Frequency Elastic Wave Propagation (KHz or MHz)

Submitted by 2008eml on

Hi everybody, I'm so interested in analysis of wave propagation in solid medias. and I've started by studying some books like "Ultrasonic wave propagation in solid media"(Rose). My question is about the importance of this analysis  (propagation of high frequency elastic waves) in the structures. I know that the major application is in the field of Nondestructive Testing(NDT). but I don't know if it is usefull in vibrational analysis of mechanical structures (elastic waves with frequencies around KHz or MHz). is this study important in "dynamic response analysis" of mechanical structures in some special kind of loading like impact? I'd be gratefull if you could introduce me some examples.