Roof Diaphragm Aspect Ratio

The maximum roof diaphragm moment m equals ww wl x l2 8.

Roof diaphragm aspect ratio.

Gypsum board diaphragm ceilings shall be in accordance with section 2508 5. Diaphragm aspect ratio is ok. Roof diaphragm aspect ratio table 3 16a1 l. 2305 2 3 diaphragm aspect ratios.

The sdi diaphragm design manual third edition is an excellent design reference every engineer should utilize if designing with steel deck diaphragms. Size and shape of diaphragms shall be limited as set forth in table 2305 2 3. Jump to full code chapter. 2306 2 3 double diagonally sheathed lumber diaphragms.

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. 3 amongst all the models only four storey building with 1 4 aspect ratio has flexibility ratio greater than 1 5 so it s. Roof systems 3 1 3 4 lumber rafters.

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. 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. 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.

2 since flexibility ratio increases with increase in aspect ratio of building we can say that flexibility of diaphragm increases with increase in aspect ratio. There is a discussion going between the engineers in my office about the acceptibility of a 4 3 1 roof diaphragm. The corresponding diaphragm chord forces are therefore equal to m divided by the diaphragm depth b. Aspect ratios of 2 1 and 1 2.

Similar changes to 2306 3 for shear walls. Analyses were performed for both loads applied in the longitudinal and transverse directions i e. But i can t find any similar limit for metal deck. Twelve large diaphragm models were created to investigate the influences of various modeling and.

2010 building code of ny 23 wood 2305 general design requirements for lateral force resisting systems 2305 2 design of wood diaphragms 2305 2 3 diaphragm aspect ratios. 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. Min 12 7 and l. Behavior of a case study all wood panelized roof diaphragm.