RC beam analysis & design (EN1992): Lever arm limit for shear different to the code
Not version-specific
Tekla Tedds
Tekla Tedds for Word
Environment
Eurocode
See the RC beam analysis & design (EN 1992) Simple Beam Example from the library.
In the calc, a lever arm, z, has to be calculated as part of the 'Rectangular section in flexure (Section 6.1)' checks. This is worked out using z = min((d / 2) x [1 + (1 - 3.53 x K)^0.5], 0.95 x d) = 422 mm This is taken straight from the Concise Eurocode 2 document, published by the Concrete Society, section 6.2. However, a lever arm value is also used in the 'Rectangular section in Shear (Section 6.2)' checks. Tedds uses the same value of z for these shear checks as the one used for the flexure checks. However, in clause 6.2.3 of EC2, it suggests a value of 0.9d, instead of 0.95d as used previously.
The difference between 0.9d and 0.95d is considered nominal. As z has already been calculated once, it seems odd to have two different lever arms, and the clause 6.2.3 says “approximate”. It should be noted that the z value being used in both checks is the calculated value, so should be more accurate in most cases. It is the limit for this value that is just marginally different.
In the calc, a lever arm, z, has to be calculated as part of the 'Rectangular section in flexure (Section 6.1)' checks. This is worked out using z = min((d / 2) x [1 + (1 - 3.53 x K)^0.5], 0.95 x d) = 422 mm This is taken straight from the Concise Eurocode 2 document, published by the Concrete Society, section 6.2. However, a lever arm value is also used in the 'Rectangular section in Shear (Section 6.2)' checks. Tedds uses the same value of z for these shear checks as the one used for the flexure checks. However, in clause 6.2.3 of EC2, it suggests a value of 0.9d, instead of 0.95d as used previously.
The difference between 0.9d and 0.95d is considered nominal. As z has already been calculated once, it seems odd to have two different lever arms, and the clause 6.2.3 says “approximate”. It should be noted that the z value being used in both checks is the calculated value, so should be more accurate in most cases. It is the limit for this value that is just marginally different.