I'm modeling a 3 stringer short span timber bridge in staad. The model consists of the three beams and deck planks (which are modeled as Plates). All geometry, material properties, supporting, and loading have been assigned. There is only one error in…

I modeled a 3 stringer bridge with plates. I created offsets for the beams, but immediately after doing that dashed lines extending out appeared. Could anyone explain what's going on here?

I'm modeling a short span timber bridge in STAAD, and using plates to model the deck planks. How do I assign either timber or user defined material properties? Also, should I insert nodes at all places I want a deck plane and define a plate there? …