Wind Shear Wall Force Roof Diaphragm

Walls for simplicity sake.

Wind shear wall force roof diaphragm.

Commercial roof diaphragm trussed roof 2x lumber capacity 350 plf case 1 peter von buelow university of michigan tcaup slide 9 of 28 three shear wall types design considerations. The edges or ends of diaphragms and shear walls are critical. The maximum roof diaphragm moment m equals ww wl x l2 8. Diaphragms and shear walls are used in the lateral design of a building the structural system is termed a box sys tem shear walls provide reactions for the roof and floor diaphragms and transmit the forces into the foundation.

Wood frame shear wall and diaphragm design ricky mclain ms pe se. Asce 7 10 outlines the procedure for calculating diaphragm design forces. The strength requirement for shear transfer between the diaphragm and wall b is. Adjacent to wall b the uniform shear force in the diaphragm is equal to r b l which is the same unit shear force in the wall.

It should also be noted that. The corresponding diaphragm chord forces are therefore equal to m divided by the diaphragm depth b. The forces described in the previous section are the forces seismic base shear puts on the frames walls. Diaphragm selection for shear force roof and floor diaphragms example 2.

The maximum unit shear on the wall diaphragm is also equal to the roof reaction r divided by b. Components will function together as a system. Structures using wood frame shear walls or wood frame diaphragms to resist wind seismic or other lateral loads shall be designed and constructed in accordance with af pa sdpws and the applicable provisions of sections 2305 2306 and 2307. These forces are different than diaphragm design forces.

Wind load diaphragm sheathing floor roof framing perpendicular to walls floor joist. Where φ 0 75 and v n is determined in accordance with the shear friction provisions of aci 318 section 22 9 4 2. An accurate method for engi neering diaphragms has evolved from analytic mod els and extensive testing and. Stud to diaphragm wind load.

A diaphragm is a flat structural unit acting like a deep thin beam. This force is then applied to the shearwalls at the roof eave height. Calculating diaphragm forces awc design aid 6 max shear at ends max moment at mid span. However the wall diaphragm moment equals r x h.

When looking at the wind tributary to a diaphragm in order to calculate the shear wall capacities i normally resolve the wind forces to the roof and half the wall height single story four ext. Figure 7 1 illustrates how the shear wall transfers the. The term diaphragm is usually applied to roofs and floors.