Punching beta factor



Brief introduction

The Eccentricity Factor β may be calculated by taking existing bending moments into account.

Detailed Technical information

Where the support reaction is eccentric with regard to the control perimeter, the maximum shear stress should be taken as:

, where β represents the eccentricity factor.

Previous versions offered only simplified method according to EN 1992-1-1, clause 6.4.3(6). SCIA Engineer 2012 extends options for setting of the eccentricity factor β.

Three new methods are defined:

  • General method according to EN 1992-1-1, clause 6.4.3(3-5)
  • General method according to general formula:
    This method calculates the biggest value of the shear stress caused by shear force and unbalanced transferred bending moments between the slab and the columns(supports). The value of β factor is calculated for each control perimeter, it means the value can be different for each control perimeter.
  • User input of β factor (only if punching data are defined)

Simplified method is used as a default.

Simplified method according to EN 1992-1-1, clause 6.4.3(6) can be used for structures where the lateral stability does not depend on frame action between the slabs and the columns, and where the adjacent spans do not differ in length by more than 25%. The value of β factor is the same for all control perimeters and depends on position of the column.

  • corner column β = βint
  • edge column (parallel x or parallel y) β = βedge
  • internal column β = βint

Radim Blažek