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poroelastic model

I am currently working on a poroelastic model for an oil basin-I have tried and read through Abaqus manual to find out how we can apply Biot's Coefficient in our model or how it takes care of it-Does anyone have any clue about this?


Yuhang Hu's picture

According to my understanding, there are two ways of prescribingporoelsticity in Abaqus.

One is to use poroelastic material model, and the other is by giving elasticmaterial properties in special states (instantaneous state and long timeequilibrium state).

You are using the first method, so you have to give logarithmic bulkmodulus, initial void ratio, shear modulus (or Possion's ratio). To answer yourquestion of where they come from, in Abaqus the elastic part of the volumetricbehavior of porous materials is
modeled accurately by assuming that the elastic part of the change in
volume of the material is proportional to the logarithm of the pressure
stress. To get the exact formular of bulk modulus in terms of average pressure,you can take a look at Abaqus ducumentation--> Abaqus user's manul-->materials-->elastic mechancialproperties-->poroselasticity-->elatic behavior of porous materials

 To use the second method, you have to give instantaneous Young'smodulus (instantaneous posson's ratio is assumed to be 1/2 automatically inAbaqus), and long time equilibrium Young's modulous  and long timePossion's ratio. You can not prescribe these properties directly in Abaqus CAE.You have to modify the in put file. There is an example in Abaqus exampleproblems Manual --> soils analysis

r.k's picture

Dear Yuhang Hu

Hope all is well with you.

 You know, these days i'm working on fully coupled hydraulic fracturing propagation in poroelastic media but my poroelastic matlab code doesn't work proparely.

I've got to finish my Msc thesis as soon as possible.

would you please do me a favor and send me any 2D poroelastic media Matlab code.


Hi Yuhang:

  Hope all is well for you.

  I am interested in modeling the poroelastic problem in ABAQUS, but I am troubled by the constitutive law of the porous material in ABAQUS. As has showned in your article and bolg 'poroelastic model', according to the Biot's linear poroelastic assumption,constitutive law is linear. But the material property is associated with the tensile limit nonlinearly in ABAQUS (This can be shown in the logarithmic bulk modulus definition, k=de/(d(ln(p+pt))). So how to explain this constitutive law in ABAQUS, or can the form of the logarithmic modulus can be derived from the Biot's theory? 

  Hoping for your reply?

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