EN 1993-1-1 (EC 3) Checks

Design of Steel Structures - Part 1-1: General Rules and Rules for Buildings

Stage structure according to EN 1993
Stage structure according to EN 1993

The steel checks according to EN 1993-1-1 can be used for polygonal beam sections made of construction steel S235-EN to S450-EN as per EN 1993-1-1, Table 3.1 and steel with a free definition of the material characteristics.

The steel checks can be used for buildings and engineering constructions under observance of the following standards:

  • EN 1993-1-1 as the base document
  • ÖNORM EN 1993-1-1 with the National Annex Austria
  • DIN EN 1993-1-1 with the National Annex Germany
  • SS EN 1993-1-1 with the National Annex Sweden

Actions, Design Situations

The checks are carried out after the static calculation. For this purpose the calculated load cases are assigned to the actions in accordance with EN 1991, Part 1. Taking into account the preset safety factors and combination coefficients, defined in EN 1990, the program automatically calculates the internal forces for the desired design situations.

Classification of Cross-Sections

For every set of internal forces the cross-section class according to EN 1993-1-1, Chapter 5.5, is automatically determined.

To this end, the stress distribution for simultaneous stress from biaxial bending and normal force in the center line of the section parts is used.

A cross-section is generally classified by the most unfavorable class of its pressure-loaded section parts.

Cross-Section Resistance

The elastic cross-section resistance is verified for all cross-sections of the classes 1 to 4. Cross-sections of class 4 are treated like class 3 if the c/t ratio does not exceed the limits of class 3 increased by a factor according to Chapter 5.5.2(9). Otherwise the check is carried out with effective cross-section properties as per EN 1993-1-5, Chapter 4.3.

The plastic cross-section resistance will be verified for all cross-sections of the classes 1 and 2 if the elastic cross-section resistance of the contemplated set of internal forces is exceeded.

Utilization, Results

The utilization is defined as the ratio between the action Ed and, depending on the user selection, the elastic or plastic resistance Rd of a cross-section.

The following results are available:

  • Utilization of the beams for each situation.
  • Maximal utilization of the beams of all situations.
  • Maximal utilization of the sections of all situations.

Additionally the extremal design values for internal forces, support reactions, deformations, soil pressures and stresses are saved for all check situations. The detailed log also lists the decisive combination internal forces of all design situations for each result location.