For full functionality of this site it is necessary to enable JavaScript. Here are the instructions how to enable JavaScript in your web browser.

# Rectangular stress distribution for the design of concrete cross-sections: the factors λ, η

## Eurocode 2 part 1-1: Design of concrete structures \$(document).ready(function () { var freeExample = \$("#freeExample").length; \$("#mainMenu li#nav-appCate, #mainMenu li#nav-appEC211").addClass("active"); var proUser = false === true || false === true || freeExample !== 0; if (!proUser) { \$('#Input input').keyup(function(){ \$('#AlertSubscribe').modal(); }); \$('#Input select').change(function(){ \$('#AlertSubscribe').modal(); }); }; var tempInput = \$("#tempInput").text(); if (tempInput != "") { \$("#Input").parent("form").deserialize(tempInput); if (proUser) { \$("#acceptBtn").trigger("click"); } }; });  3.1.7 (3)

For the design of concrete cross-sections, a rectangular stress-strain distribution may be assumed as in Figure 3.5:

 λ = 0,8          for fck ≤ 50 MPa (3.19) λ = 0,8 - (fck - 50)/400   for 50 < fck ≤ 90 MPa (3.20) and η = 1,0          for fck ≤ 50 MPa (3.21) η = 1,0 - (fck - 50)/200   for 50 < fck ≤ 90 MPa (3.22) Note: If the width of the compression zone decreases in the direction of the extreme compression fibre, the value η fcd should be reduced by 10%.

where:

x
is the neutral axis depth
λ
is the factor defining the effective height of the compression zone and the factor
η
is the factor defining the effective strength
fck
is the characteristic compressive strength of concrete, see Table 3.1
fcd
is the design compressive strength of concrete, see § 3.1.6 (1)P.

This application calculates the factors λ, η from your inputs.

Input

Output
fck
MPa Table 3.1
λ
η