What is yield line method?
What is yield line method?
Yield line design is a well-founded method of designing reinforced concrete slabs. It uses yield line theory to investigate failure mechanisms at the ultimate limit state. It is a robust and proven design technique that challenges designers to use judgement; once grasped it is an exceedingly powerful tool.
What is yield line analysis?
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.
What is yield line in civil engineering?
The yield-line technique is the traditional method of determining the (flexural) collapse load of reinforced concrete flat slabs and steel plates. Most civil/structural engineers will have encountered the technique during their undergraduate education and will be familiar with the concepts.
Why is yield line theory applicable to reinforced concrete slabs?
Yield Lines in Concrete Slabs This crack formation is seen in under reinforced concrete slabs and the yield line theory considers only under reinforced concrete slabs. During the crack formation in the slabs, the reinforcement starts to yield. This yielding happens at the point of maximum bending moments.
What are the characteristics of yield line?
| • | 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 |
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 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 are the characteristics of yield lines?
What are the methods of yield line analysis of slabs?
There are two methods of yield line analysis of slabs: (1) the equilibrium method (2) the virtual work method In either method, a YL pattern is assumed so that a collapse mechanism is produced. Then for that failure mechanism, the geometric parameters that define the exact
What is a a yield line?
A yield line is a line in the plane of the slab across which reinforcing bars have yielded and about which excessive deformation (plastic rotation) under constant limit moment
How is the ultimate load of a slab determined?
Based on principle that work done by external forces in undergoing a small virtual displacements is equal to the internal virtual work done in rotations along yield lines, the ultimate load which the slab can sustain is determined. In other words, the work during small motion of collapse mechanism is equal to the work absorbed by the plastic
Is the simple diagonal yield line in the corner correct?
hence, the simple diagonal yield line in to the corner is correct with out modification. 2.6 Slabs with more than one variable So far the slabs consider have only one variable dimension which defines the yield line mechanism. When the slab has more than one variable, the work equation, together with
