What is a wood frame diaphragm?
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A diaphragm is a flat structural unit acting like a deep, thin beam. The term “diaphragm” is usually applied to roofs and floors. A shear wall, however, is a vertical, cantilevered diaphragm.
What is diaphragm in design?
A diaphragm is a flat structural unit acting like a deep, narrow beam. The term ‘diaphragm’ is usually applied to roofs and floors. A shear wall, however, is just a vertical diaphragm. Shear walls provide support for the roof and floor diaphragms transmitting forces into the foundation.
What is seismic diaphragm?
Diaphragms transmit inertial forces from the floor system to the vertical elements of the seismic force-resisting system. They also tie the vertical elements together and thereby stabilize and transmit forces among these elements as may be required during earthquake shaking.
How do you calculate the shear of a diaphragm?
The Figure 2 average shear (S) in the diaphragm is determined by dividing the shear by the length of the diaphragm at the location in question.
Are wood diaphragms flexible?
Wood-frame diaphragms are permitted to be idealized as flexible per Section 12.3.
What is the difference between rigid and flexible diaphragm?
Flexible vs. For flexible diaphragms, the loads should be distributed according to the tributary area, whereas for rigid diaphragms, the load should be distributed according to the stiffness.
What is a diaphragm building structure?
A diaphragm wall is a structural concrete wall constructed in a deep trench excavation, either cast in situ or using precast concrete components.
What size diaphragm do I need?
The most common size is 75 millimeters (mm). It is important that your diaphragm fits right. Your doctor will show you how to insert it properly and help you practice. It should rest right behind your pubic bone.
What type of plywood is used for shear walls?
You need the right type of Plywood The two types of plywood available are Rated and Structural One, but for shear wall use the plywood must have 5 plies. Rated Plywood can be made of any species of wood while 10% stronger Structural 1 must be made of denser Southern Pine or Douglas Fir.
What is semi rigid diaphragm?
The Semi-Rigid diaphragm is sub-meshed into a Finite Element Analysis (FEA) with plates that represent the stiffness of the diaphragm. As the loads are applied into a Semi-Rigid diaphragm the flow of the diaphragm deflects as shown below.
What is a diaphragm design?
designed for seismic forces applied independently in each of the two orthogonal directions. For structures assigned to Seismic Design Categories C through F and having non- parallel systems or plan irregularity type 5, however, diaphragm design must consider the interaction of orthogonal loading in one of two ways.
How do you determine diaphragm design forces?
See also NEHRP Seismic Design Technical Brief No. 4 “Nonlinear Structural Analysis for Seismic Design ” (Deierlein et al. 2010). Capacity-based design is another way to determine diaphragm design forces. This approach uses the maximum force that can
What does NEHRP 10-917-4 stand for?
Seismic Design of Cast-in-Place Concrete Diaphragms, Chords, and Collectors: A Guide for Practicing Engineers (NIST GCR 10-917-4) Author NIST Subject NEHRP Seismic Design Technical Brief No. 3 Created Date 9/22/2010 4:39:58 PM
Why model diaphragm flexibility at the level of irregularity and adjacent floors?
Where vertical irregularities occur in the vertical elements of the seismic force-resisting system, rigid diaphragm models may produce force “spikes” that are unrealistic and difficult to design for. By modeling diaphragm flexibility at the level of irregularity and adjacent floors, more realistic transfer distributions can be obtained.