Forced to return to consideration of DualSPHysics by the appalling CPU-only performance of Realflow (that is, if you want to have objects that float properly), I'm looking at ways to implement the application of torque resistance, articulated joints and springs.
The essence of my application is this: I want to simulate the performance of a wave energy device that will have a component that rotates as a result of a wave passing by. In order to measure the performance of the device I need to be able to apply a certain amount of rotational resistance when the load of water attempts to make it rotate, and subsequently to measure the amount of actual rotation that takes place against the known resistance to work out the power produced. And through simulating with different torque resistances, to ultimately find out the resistance (as a proxy for a generator load) that produces the maximum power.
So I could do with some way of applying a consistent resistance to something rotating, and also having a springy connector between two objects. I see in the materials file that friction is one of the parameters, as is young's modulus. But it's not clear to me how I can join two objects made with different materials together - is this possible, other than locking them together through design? For example, if I have two objects that through their shape are joined by what amounts to a flexible joint (eg, interlocking rings), am I also able to connect a shape made from a springy material between the two items? Or would that also have to be interlocking through physical shape rather than being 'joined'?