Hello all, I am using deal.ii to solve a 3D solid mechanics problem. My code uses P4est and Petsc.
I am solving two equations one after the another such that the *reactions* (Stiffness matrix X Solution Vector) calculated from the first equation gives the global assembled *system_rhs* for the second equation. But this *system_rhs* is *not* *condensed *(deal.ii terminology), which means that the boundary conditions or constraints of equation 2 are yet to be applied. The constraints for the second equation are of the type (example) 1) dof1 - dof2 = 4; 2)dof3 = 0 and several others Also, the system_rhs has non-zero value for nodes at the boundary of the the domain. After assembling system_matrix_eq2 without any constraints, I tried using constraints.condense(system_matrix_eq2, system_rhs); But this function is not implemented for PetSc Matrices. Had the constraints only been homogenous, I could have used MatrixTools::apply_boundary_values() My question is, for the second equation, how should I assemble the stiffness matrix and how should the constraints be applied on* already assembled global system_rhs.* Now, How should I apply all these homogeneous and inhomogenous constraints to the system. Extra Information: The first equation is the usual equilibrium equation. It is solved to give displacements. The stiffness matrix is then multiplied by this global displacement vector to give the global traction vector which forms the rhs for the second equation. Thanks, - Rajat Arora -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
