What is a yield line pattern?
What is a yield line pattern?
Along the yield lines, there is uniform distribution of bending and twisting moments. The amount of reinforcement in the section will reflect the capacity that will give the maximum moment capacity of the section. The yield lines are lines of intersection of two planes, hence they will remain straight.
What are the characteristic features of yield lines?
| • | Yield-lines are straight except where a region may become completely plastic at any point; |
|---|---|
| • | The yield-line between two or more bordering rigid regions must pass through the intersection of the axes of rotation of these regions; |
| • | Axes of rotation usually lie along supported edges or column lines; and |
Which among the following are the assumptions made in yield line analysis of slabs?
20.2.1 Assumptions The yield line analysis of RC slab is based on the following assumptions : (a) The reinforcing steel yields fully along the yield lines. (b) The bending and twisting moments are uniformly distributed along the yield lines and have the maximum values provided by the ultimate moment capacities.
What are the advantages of yield line design?
Yield line design has the advantages of (economy, simplicity and versatility), yield line design leads to slabs that are quick and easy to design, and are quick and easy to construct. The European Concrete Building Project at Cardington, which tested a variety of methods of designing flat slabs.
What is yield line in slab?
The yield line analysis is an upper bound method in which the predicted failure load of a slab for given moment of resistance (capacity) may be higher than the true value. Thus, the solution of the upper bound method (yield line analysis) may result into unsafe design if the lowest mechanism could not be chosen.
Why corner steel is provided in slab?
Corner restrained in the slab reduces the bending moment and deflection in the middle of the slab just like fixed beam which reduces the mid-span moment and deflection as compared to simply supported beams.
What is yield line analysis?
What does Isotropically reinforced slab mean?
A slab is said to be isotropically reinforced if it is reinforced identically. in orthogonal directions and its ultimate resisting moment is the same in these two directions as it is along any line regardless of its direction.
What is yield line analysis of slabs?
What are the limitations of yield line theory?
When the actual yield surface of the plate is different from the upper yield surface, then the yield load predicted by limit analysis can generally not be determined by yield-line theory. It is not even possible to approach the solution by successive refinement of the yield-line pattern.
What is the minimum dia of bar?
As per IS 456:2000, in rcc slab, minimum diameter of main bar should not be less than 8mm (highly yield strength deform bar HYSD) or 10mm (plain bar) and distribution bar should not less than 8mm.
Why is torsion reinforcement in slabs?
Torsional reinforcement shall be provided at corner of two way slab. The torsional moment are high near the corner therefore, torsional reinforcement is essential to prevent corner slab from lifting and prevents cracks. It is provided when required.
What is yield line theory in concrete slabs?
Yield Lines in Concrete Slabs As mentioned before, the analysis is conducted based on the collapse load of the slab under consideration. Under this load, cracks are formed. This crack formation is seen in under reinforced concrete slabs and the yield line theory considers only under reinforced concrete slabs.
What is the difference between straight and one way slabs?
Straight yield line occure between two intersecting planes. In one way slabs, the positive yield line occur at the mide span. At the supports, the yield lines are negative in addition to the mid positive yield lines for one way continuous slabs. For slabs with a point load, the yield lines will be projecting out of the point of application.
What type of inelastic analysis is used for two-way slab systems?
In the case of two-way slab systems, which are statically indeterminate, detailed inelastic analysis (yield line analysis) is conducted. The moment coefficients given in the Code IS 456:200 (Table 26) for two-way rectangular slabs with various possible edge conditions are based on Yield Line Analysis.
What is yield line analysis in steel reinforcement?
‘Yield line analysis’ is the equivalent for a two-dimensional flexural member (plate or slab) of the limit analysis of a one-dimensional member (continuous beam). At the collapse stage, the steel reinforcement will be fully yielded along the yield lines.
