Welcome to ask.woodem.org. You may post when you login through your GitHub account.

Contact stiffness K_n formulation

0 votes
12 views
asked Nov 26 by trucgiao91 (410 points)
edited Nov 26 by trucgiao91

Hi Vaclav,

recently I was looking into ContactLoop and saw that Contact stiffness K_n are formulated for ConcreteMat differently compare to that for FrictMat. 

while in FrictMat (here K_n)

K_n = 1/(E1A1/l1 +E2A2/l2)

Concrete Mat to my understanding is more or less obtained by averaging E1 and E2 of two particles (link to code here K_n):

K_n=(E1+E2)*0.5*A/(l1+l2)

 

Is there a reason behind it? to me the first formulation makes more sense, since the stiffness will depend on the softest material.

 

Best regards,

Giao

1 Answer

0 votes
answered 5 days ago by eudoxos (48,170 points)
Hi Giao, you are right, the FrictMat formulation is better (IIRC the historical reason was to avoid using any geometry (ContactGeom) information in ContactPhys functor, which is not relevant now). Feel free to adjust the code and do a pull request with the update :) vaclav
...