I want to do a transient simulation of a structural mechanics problem where I apply a bias which is to be solved using a static PDE, and a transient response where a unit step or sinusoid is applied on top of the bias/DC input.
If I solve the problem with only transient simulation giving it a DC+AC input, the method actually applies a unit step corresponding to the the DC input and a time varying signal corresponding to the AC. Needless to say, due to the large DC step, the natural response completely dwarfs the forced response.
One way to do this is to do two simulations: the output shape of the first simulation serves as the input for a second transient elastodynamics simulation.
While I can capture the displacement with a moving mesh, I am not sure how to capture the stresses stored in the structure in the input of the elastodynamics problem.
Another alternative is to utilise the Lagrangian formulation and instead of moving the mesh we just update the jacobian matrix. While I am sure this will capture the “initial deformation” for the transient simulation, but not sure if it captures the initial stress. If anyone has solved similar problems, can you please share how you solved this problems.