Blog posts

I am trying to develop a model in ABAQUS and perform crack analysis using FRANC3D. I am having a problem right at the beginning.

I am able to create the model in ABAQUS and write the .inp file. I open this file in FRANC3D and am trying to insert a curved crack. I repeat a 'curved crack'. The crack is not planar. When I try to define the crack front using 'user defined points', the software is approximating all the points I enter to a best-fit 'plane'. So it is generating a planar crack when i wanta curved crack.

As a follow up to my first blog , I would like to know if the experimental data of applied loads and crack sizes or lengths, are sufficient to model the R-curve behaviour via the Fracture Mechanics approach.

 A linear constitutive thermodynamic relation between thermodynamic force f and flux v.

v = Mf, where M is the phenomological coefficient. 

How to constitute a nonlinear thermodynamic constitutive relation for an unknown system which we expect to exibit nonlinear behaviour?

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To be considered, applicants must satisfy the requirements described in the attached flyer and submit a cover letter and resume directly to the ExxonMobil website (www.exxonmobil.com/ex).

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_t are stresses under compression and tension, respectively.