I want to get two imported mesh pieces to be one mesh (actor). Then have another blueprint to spawn it and throw the combined mesh actor in the air. Then, when the combined mesh actor got hit by other actor it turns into 2 separate pieces also affected by force (add radial force), for example.
In the actor just add two static mesh components then set each component to either mesh. Parent one component into the other component so it can “carry” that component initially. Set the parent mesh component to simulate physics, make sure the child mesh component is not set to simulate physics. Add a custom event (or a hit event), make this event turn on simulate physics for the child component.
alternatively, you could have 1 mesh component with the whole mesh, then on hit, change this mesh to the half mesh, add a new mesh component as the second half mesh.