Roof Diaphragm Chord

Examples of chords are shown in figure 4 28.

Roof diaphragm chord.

The diaphragm forces tend to be transferred to the vertical resisting elements. I designed the metal deck roof deck diaphragm and it can tranfer the lateral loads to the shear walls on each end. Roof chord continuity 4 5 1 4 openings at shear walls. Curved diaphragms idealize it as flat.

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. Roof diaphragm chord for the diaphragm the chords carry the moment couple and the panels carry the web shear tension generally controls. My chord force for the diaphragm is 4 2 kips. The roof and foundation support the vertically spanning wall and consequently pick up the developed horizontal reactions.

The corresponding diaphragm chord forces are therefore equal to m divided by the diaphragm depth b. Not asd divide nominal values by 2 0 for asd capacity. Chord reinforcement must be provided in addition to any other required reinforcement such as flexural reinforcement. Idealizing and simplifying complicated structures.

This horizontal element is known as the diaphragm. Diaphragm sheathing floor roof framing parallel to walls add blocking floor joist blocking. Diaphragm openings immediately adjacent to the. The maximum unit shear on the wall diaphragm is also equal to the roof reaction r divided by b.

T chord t c chord c w diaphragm reaction goes to shear walls. Chords are usually the double top plates of the walls but for simple but jointed members only 1 member is acting at the joint. 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. How does a sloped sheeted roof roof trusses 4 12 relate to the classic diaphragm modle which is presented as horizontal beam with roof edges acting as chords and the sheeting acting as the web.

However the wall diaphragm moment equals r x h. Sloped roofs idealize sloped wood roof diaphragms as if they are flat. At the roof level these wall reactions turn the load in the roof system in the plane of the roof. It should also be noted that.

Offset roof planes offset roof planes treat as two separate diaphragms each with. I am using the steel roof beam at the perimeter of the building to act as the chord member.