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Steel code check (esasd.01)

esasd.01

The *Steel Code Check* is an interactive functionality that performs section and stability design of steel members. Code-compliant checks follow FEM analysis; these take into account 2^{nd} order deformation and imperfections either on the level of analysis, or on the level of the checks. Module esasd.01.xx automates the design rules published in the following structural codes: EN 1993-1-1^{1}; NEN 6770/6771; AISC 360 (ASD & LRFD); ÖNORM B 4300; SIA 263; CM 66; DIN 18800, Teil 1 & 2; BS 5950-1.The interaction of load effects and the various types of buckling are correctly handled.

The program supports the therein included methods, safety factors and coefficients that are of significance to structural analysis and design.

Highlights |
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Design of steel elements of section classes 1 to 4 -- i.e. compact to slender cross-sections. |

Choice of appropriate design equations based on section class and overall slenderness. |

Support for members with haunches, integrated beams, fabricated sections. |

User-defined system type (sway or non-sway), diaphragms, lateral restraints and bracing. |

Buckling lengths are calculated automatically based on the defined boundary conditions and sway system; buckling lengths for all types of instability may be overwritten by the user. |

Global and member imperfections can be taken into account in 2^{nd} order analysis. |

Comprehensive analysis of all defined/generated load combinations for the sake of finding the extreme values of unity checks. |

Preview of results via the 3D graphical environment -- colour-coded diagrams on members, results in table form;. |

Cross-section AutoDesign (and overall AutoDesign via module esa.11) seeks for the optimal geometrical shape and arrangement. |

Clear reports at different levels of detail. |

Detailed reports contain intermediate calculation steps and references to clauses and equations in the respective norm. |

Code-dependent safety factors and coefficients are clearly listed. |

In combination with the module Steel Cold-formed, the Steel Code Check feature allow for cold-formed steel elements to be designed in full accordance with EN 1993-1-3 or AISI S-100. |

In combination with the module Plastic Analysis Steel Structures (esas.15 ), material plasticity can be represented in the analysis by the automatic generation of plastic hinges. |

## Benefits

- Support for a wide variety of symmetrical and asymmetrical profiles;
- Available libraries - steel profiles, materials, roof and floor diaphragms, etc.;
- Code checks per member or per selection of members eliminates potentially long calculation runs for large projects;
- Seamless integration into the user interface and graphical environment of SCIA Engineer;
- Smooth transition from structural analysis (linear, stability, 2
^{nd}order, etc.) to code-compliant design controls; - Explicit settings for lateral-torsional buckling - buckling length, position of load (stabilizing, neutral, destabilizing), effective length factors, LTB restraints;
- Unity check values are displayed as diagrams along the structural members;
- The degree of utilisation of each cross-section is expressed by colour-coding the unity check diagrams (grey for over-dimensioned parts, green for sections that fulfil the check, and red for under-dimensioned sections). Colour-coding makes it easy for the user to visually assess the outcome of design.
- The Engineering Report gathers all steps of structural analysis and design - the modelled geometry, internal forces and deformations, the performed section and stability checks, etc.

## Summary of performed checks

- Classification of cross-sections;
- Critical slenderness (prescriptive);
- Section checks for:
- normal force (tension/compression);
- bending moments;
- shear forces;
- torsion;
- section warping in I-, U- and thin-walled sections;
- combination of load effects (axial force + bending moments + shear force);

- Stability checks for:
- flexural (Euler) buckling for axially loaded elements;
- torsional and torsional-flexural buckling for axially loaded elements;
- lateral-torsional buckling for members loaded in bending;
- shear buckling and effect of lateral forces for elements loaded in shear;
- buckling in combined bending and axial compression;

- Buckling of slender flanges for integrated beams or 3-plate welded beams;

An overview and detailed accounts of all implemented design methods and equations per code can be found in the Theoretical Background for steel design (available via the Help menu of SCIA Engineer).

## Supported cross-sections

- Symmetric and asymmetric I-sections (hot-rolled and welded);
- Rectangular and circular hollow sections;
- Angles, U-, T-, C-sections;
- Rectangular and circular solid sections and flat strips for bracing;
- Tapered I-sections (with variable height), sections with haunches;
- Integrated beams, such as IFB, SFB and THQ sections (built-in)
- General sections with arbitrary shape;
- Numerical sections.

## Unique features

Optimisation:

- The automatic cross-section optimisation of SCIA Engineer considerably reduces the time needed for selecting suitable profiles for all members in a structure;
- The cross-section optimisation routine uses the maximum allowable unity check threshold and cycles through the Profile Library or through a set of steel profiles selected by the user;
- The program determines the lightest profile that satisfies the unity checks;
- Global optimisation (requires module esa.11) allows the user to select which parameters of the structure (related to geometry, material, etc.) he would like to adapt in order to obtain an optimal structure (in terms of material use, practical feasibility, etc.);

Modifiers of stability behaviour:

- Shear stiffeners may be defined on modelled beams and be taken into account in the analysis of web buckling under shear forces;
- Diaphragms can be defined and their effect on the lateral torsional buckling of 1D members can be taken into account;
- Special formulas calculate the buckling length of crossing diagonals.

^{1}National Annex support is available for a number of countries (Austria, Belgium, Czech Republic, Finland, France, Germany, Greece, Ireland, Luxembourg, The Netherlands, Poland, Romania, Slovakia, Slovenia, United Kingdom). Methods and individual values specific to a National Annex are available and can be reviewed and, if needed, adapted.

30/10/2014