Hello, everyone

I am very confused about Dirichlet Boundary Conditions.

Such as the example given by the manual:

[pylithapp.problem]

bc = [mybc]

[pylithapp.problem.bc.mybc]

label = group A

bc_dof = [2] ; fixed displacement in z direction

db_initial = spatialdata.spatialdb.SimpleDB

db_initial.iohandler.filename = disp_A.spatialdb

db_initial.query_type = nearest ; change query type to nearest point algorithm

db_rate = spatialdata.spatialdb.UniformDB

db_rate.values = [displacement-rate-z]

db_rate.data = [1.0e-06 * m/s] ; velocity is 1.0e-06 m/s

From the manual, bc_dof = [2] (fixed displacement in z direction) means the displacement in z direction is fixed, but it laterly says group A moves at a speed of 1.0e-06 m/s in the z direction. How could this happen? Group A is fixed and moves at a speed of 1.0e-06m/s in z direction at the same time? I mean if Group A is fixed, it cannot move, right?

Hope someone can give a detailed explanation.

Best regards,

Tu Xiang