Robin Boundary Conditions

[Colin McAuliffe]

Hello all,

Does FEAP have commands to define Robin BC's such as surface convection and elastic boundaries?

Thanks
Colin

[FEAP_Admin]

For simple elastic boundaries you could use elastic springs (point elements) or nodal springs.  For more complex BC a user element is probably the best way to go.

[Prof. S. Govindjee]

Colin,
  Have a look at http://www.ce.berkeley.edu/~sanjay/FEAP/lysmer.html for an example user element for a 'complex' boundary condition:  d[traction]/dt + M v = 0 where traction = sigma^T n, M is a matrix, and v = velocity.