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.
What is a horizontal diaphragm?
Similar to a shear panel, a horizontal diaphragm is a horizontal truss (in a roof plane) or solid sheet element (in a floor). It is placed between vertical elements to transfer lateral loads to the vertical elements, such as shear panels, vertical trusses or moment frames.
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 the role of diaphragm in seismic force?
Diaphragms are components of low-rise wood frame buildings that resist lateral forces due to wind and earthquakes. The main function of these panel type structures is to resist in-plane shear forces and to provide stability to the overall structure.
What are seismic dampers and why are they important?
Seismic dampers are used in buildings, bridges or any other constructions to control earthquake induced vibrations on buildings. When seismic waves start to penetrate a base of building structure, seismic dampers can decrease their damaging effect and improve the buildings seismic performance.
What is concrete diaphragm?
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.
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 an example of diaphragm?
The thick muscular partition that separates your thorax from your abdomen is an example of a diaphragm. A barrier that fits over the cervix and prevents pregnancy is an example of a diaphragm. A part of a camera that controls the size of the lens’ aperture is an example of a diaphragm.
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 is diaphragm ceiling?
The ceiling diaphragm: 1. Provides restraint to the bottom chords of roof trusses under compression occurring from wind uplift 2. Works as a mechanism to transfer lateral wind loads to wall bracing elements/bracing walls.
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
What are the recommended design provisions of the NEHRP P-751?
FEMA P-751, NEHRP Recommended Provisions: Design Examples Chart 1.10 Soil-Structure Interaction (SSI) 1– 22 Linear Analysis (ELF and MRSI Analysis, per requirements of Sec. 19.1.1) Determine effective period lengthening ratio, (T/T)