My employer has a tech exchange with other large companies, and we recieved a presentation from a structural acoustics guy from Boeing about the new 787.
He showed us slides and pictures of how the fusleage is made for the new 'liner, and it struck me as really odd. The fuselage is carbon laminate (not sandwhich, which is used in the tail and control surfaces) and looks like it is wound on an expanding mandrel out of carbon pre-preg tape. Then they install stiffeners (their word) longerons - about dozen around the circumference - and ribs about every 16" down the whole length of barrel. These ribs look to be about 6 inches deep and are installed while holding the fuselage in one jig (I think to keep it round) while another set of jigs are used to drill the barrel and install the fasteners...
There was no time for questions during the presentation, so I submitted my questions off line, but this sure seems to be skipping all of the advantages of sandwich construction, while keeping everything that is bad about metal, like high part count, complexity at assembly, etc. They have not answered yet...
Since they know how to build sandwich parts, does anybody KNOW why they chose to build the fuselage this way?
Billski
He showed us slides and pictures of how the fusleage is made for the new 'liner, and it struck me as really odd. The fuselage is carbon laminate (not sandwhich, which is used in the tail and control surfaces) and looks like it is wound on an expanding mandrel out of carbon pre-preg tape. Then they install stiffeners (their word) longerons - about dozen around the circumference - and ribs about every 16" down the whole length of barrel. These ribs look to be about 6 inches deep and are installed while holding the fuselage in one jig (I think to keep it round) while another set of jigs are used to drill the barrel and install the fasteners...
There was no time for questions during the presentation, so I submitted my questions off line, but this sure seems to be skipping all of the advantages of sandwich construction, while keeping everything that is bad about metal, like high part count, complexity at assembly, etc. They have not answered yet...
Since they know how to build sandwich parts, does anybody KNOW why they chose to build the fuselage this way?
Billski
