Roof Diaphragm Chord

The diaphragm forces tend to be transferred to the vertical resisting elements.

Roof diaphragm chord.

I designed the metal deck roof deck diaphragm and it can tranfer the lateral loads to the shear walls on each end. Roof diaphragm chord for the diaphragm the chords carry the moment couple and the panels carry the web shear tension generally controls. It should also be noted that. Diaphragm openings immediately adjacent to the.

Curved diaphragms idealize it as flat. Chord reinforcement must be provided in addition to any other required reinforcement such as flexural reinforcement. Chords are usually the double top plates of the walls but for simple but jointed members only 1 member is acting at the joint. The maximum unit shear on the wall diaphragm is also equal to the roof reaction r divided by b.

Sloped roofs idealize sloped wood roof diaphragms as if they are flat. Unblocked diaphragm capacity capacities in sdpws are nominal values. Idealizing and simplifying complicated structures. The diaphragm chord can be a line of edge beams that is connected to the floor or reinforcing in the edge of a slab or in a spandrel.

The roof and foundation support the vertically spanning wall and consequently pick up the developed horizontal reactions. Not asd divide nominal values by 2 0 for asd capacity. In the case of roof and floor systems without perimeter beams the chord reinforcing bars are typically concentrated near the edge of the slab and are tied to either the top or bottom flexural reinforcement. At the roof level these wall reactions turn the load in the roof system in the plane of the roof.

The corresponding diaphragm chord forces are therefore equal to m divided by the diaphragm depth b. The picture i see is a flanged beam with a large buckle in the middle and i have difficulty expecting that this condition can replace a flat horizontal diaphragm provided by sheeting the underside. My chord force for the diaphragm is 4 2 kips. Examples of chords are shown in figure 4 28.

Offset roof planes offset roof planes treat as two separate diaphragms each with. Roof chord continuity 4 5 1 4 openings at shear walls. I am using the steel roof beam at the perimeter of the building to act as the chord member. T chord t c chord c w diaphragm reaction goes to shear walls.

However the wall diaphragm moment equals r x h. In structural engineering a diaphragm is a structural element that transmits lateral loads to the vertical resisting elements of a structure such as shear walls or frames diaphragms are typically horizontal but can be sloped such as in a gable roof on a wood structure or concrete ramp in a parking garage.