[CIG-SHORT] Dynamic simulation with absorbing boundary

[Birendra jha]

Hi 

I am working on a problem similar to bar_shearwave/quad4/spontaneousrup.cfg. The domain is a square, fault is slightly inclined, and instead of driving the fault with traction perturbations, I am using Neumann BC on top and right. Given that it creates a normal faulting condition, I would like to use Absorbing Boundary on the left and right edges. Is it possible to have both Neumann and Absorbing BC on same boundary (like Dirichlet and Absorbing on the same boundary)? It seems not, because absorbing BC sets the boundary traction equal to that of the outgoing wave, and it does not have to be equal to the imposed Neumann tractions. 

For such a setup (dynamic simulation, explicit timestepping, fault driven by boundary tractions), how should I impose the Absorbing BC?

Thanks and regards
Birendra