Aluminum Frame vs Wood Frame for washboard roads.

I no longer own Airstream, so have to relay on google pictures.
Here is a picture showing gutted frame.
Floor is definitely welded members, when I can't find close-up how walls frame is connected. Looks welded on this picture, but can't say for sure.
Fact is that Airstream made ingenious construction, where both walls and ceiling have single frame member bend to the shape.


Found close up on window frame. You can clearly see weld on it.