There is a discussion going between the engineers in my office about the acceptibility of a 4 3 1 roof diaphragm.
Roof diaphragm aspect ratio.
Gypsum board diaphragm ceilings shall be in accordance with section 2508 5.
Diaphragm aspect ratio is ok.
The dimensions of the case study diaphragm were 192 ft x 96 ft.
Double diagonally sheathed lumber diaphragms shall be designed and constructed in accordance with af pa sdpws.
Roof systems 3 1 3 4 lumber rafters.
Twelve large diaphragm models were created to investigate the influences of various modeling and.
Rafter span horizontal projection 26 16 rafter spacing 24 16 eave overhang length lesser of 2 or rafter length 3 2 rake overhang length lesser of 2 or outlooker length 2 2 roof slope 1 5 12 12 7 12 roof diaphragms.
Wood structural panel unblocked 3 1 wood structural panel blocked 4 1 single layer straight lumber sheathing 2 1 single layer diagonal lumber sheathing 3 1 double layer diagonal lumber.
2305 2 3 diaphragm aspect ratios.
Size and shape of diaphragms shall be limited as set forth in table 2305 2 3.
The sdi diaphragm design manual third edition is an excellent design reference every engineer should utilize if designing with steel deck diaphragms.
Aspect ratios of 2 1 and 1 2.
Behavior of a case study all wood panelized roof diaphragm.
2306 2 4 gypsum board diaphragm ceilings.
The maximum roof diaphragm moment m equals ww wl x l2 8.
Diaphragm aspect ratios sdpws table 4 2 4 type maximum length width ratio for an 84 x 34 diaphragm the aspect ratio is 2 5 3.
3 amongst all the models only four storey building with 1 4 aspect ratio has flexibility ratio greater than 1 5 so it s.
Jump to full code chapter.
I know for plywood diaphragms the codes limit it to 4 1 aspect ratio.
The maximum unit shear on the wall diaphragm is also equal to the roof reaction r divided by b.
2306 2 3 double diagonally sheathed lumber diaphragms.
Similar changes to 2306 3 for shear walls.
The corresponding diaphragm chord forces are therefore equal to m divided by the diaphragm depth b.
The manual includes pertinent design information considerations fastener information deck shear capacity tables and a plethora of highly relevant design examples stepping you through all the intricate details and covering nearly any.
But i can t find any similar limit for metal deck.
Min 12 7 and l.
Analyses were performed for both loads applied in the longitudinal and transverse directions i e.
Wood diaphragm chords aspect ratios hokie66 structural 2 jan 11 14 56 when it gets too complicated to brace at the roof level brace at the ceiling level.
