How do I change the direction of a one way slab in Etabs?
It can be done very easily. Just draw the slab after after doing it select the slab go to ASSGIN-SHELL-LOCAL AXIS – there you will get freedom to rotate the slab from its current position, for rotating the slab toward longer direction make 90 degree orientation.
How do you distribute point load on a slab?
The load distribution from one way slab is 50\% to either of the beams parallel to the longer side of the slab. For two way slabs, it is presumed to be two triangles of the slab area one each on the shorter side, and also two trapeziums one each on the beams parallel to the longer side.
How do you distribute slab load on a beam?
The slab is commonly divided into trapezoidal and triangular areas by drawing lines from each corner of the rectangle at 45 degrees. The beam’s distributed load is computed by multiplying the segment area (trapezoidal or triangular area) by the slab’s unit load divided by the beam length.
How do you make a one way slab safe?
To enforce one-way action, assign small m11 or m22 stiffness modifiers to the slab. These modifiers, available through Assign Area > Stiffness Modifiers, should be applied relative to the local axes and the desired direction of one-way action.
What is one way and two way slab?
In one way slab, the load is carried in one direction perpendicular to the supporting beam. In two way slab, the load is carried in both directions. In two-way slab, the crank is provided in four directions. If L/b the ratio is greater than or equal 2 or then it is considered a one-way slab.
How are building loads transferred to foundations?
Walls, like columns, transmit loads by compressive force to the floor below, another wall, or earth through the foundation wall. The wall unit will react to force like a long slender column. A wall may also be required to act like a beam, resisting flexing force such as a wind load.
How do I add mass sources to Etabs?
If you choose a membrane element, apply your area loads to the slab/deck, run the analysis, display menu>load assign>frame> Load type>All loading that is tributary to the frame object. ETABS will then show you the tributary uniform line load to each beam which should match your hand calculations.
How load is transferred?
“Load transfer” is a term used to describe the transfer (or distribution) load across discontinuities such as joints or cracks (AASHTO, 1993). When a wheel load is applied at a joint or crack, both the loaded slab and adjacent unloaded slab deflect.
How to use ETABS to load tributary load?
If you choose a membrane element, apply your area loads to the slab/deck, run the analysis, display menu>load assign>frame> Load type>All loading that is tributary to the frame object. ETABS will then show you the tributary uniform line load to each beam which should match your hand calculations.
How is the load distributed on a two way slab?
Triangular load distribution in two way slabs Here, since the dimension of slab is same in both directions, all the 4 walls equally share the weight of the slab. Hence load is distributed in a triangular fashion as shown above.
How do I change the stiffness of a slab?
For a shell element change the stiffness modifier of M11 OR m22 = 0.05 or a very small number, perpendicular to the direction of the span. So if your slab spans along local axis 1, change M22=0.05. Alternatively you can use a membrane and check the one-way slab action option.
Why do beams share the load carrying capacity of a slab?
This is because the shell element (concrete slab) is carrying some of the loads through flexure of the slab. Therefore the slab and beams will share the load carrying capacity. However, your hand calculations dumps 100\% of the loads to the beams (supports) in the same way that ETABS membrane element does.