Penalty for Zero Length Contact Element

[duttaANURAG]

Good Morning Community,

While using the Zero Length Contact Element in Wall- Backfill Problems, we have to provide Penalty in normal direction and penalty in tangential direction.
The element command in OpenSees is as follows -

element zeroLengthContact2D $eleTag $sNode $mNode $Kn $Kt $mu -normal $Nx $Ny

Please tell me how to get the values for penalty $Kn and $Kt for these Zero Length Contact Element, as it has not been provided here in OpenSees page.

Please help me. Your help will be appreciated a lot.

Thank You.

[fmk]

these are penalty factors that enforce the constraing .. it depends on the model you have. you want something large enough to enforce the constraint (as number goes towards infinity the constraint is enforced exactly) , but not too large to effect the conditioning of the global stiffness matrix and hence the results .. a number a few factors larger than the stiffness of the largest term in the matrix is usually sufficient

[duttaANURAG]

Thank You Sir.