enabling innovation in construction steel construction highlights a complete steel solution in scia...

enabling innovation in construction

Steel construction highlights

A complete steel solution in Scia Engineer

Overview

• True Analysis – Analysis and structural model in parallel

• Implementation of EN1993

• Built-up welded sections

• Fire resistance

• AutoDesign – Optimisation

• 2nd order lateral torsional buckling

• ArcelorMittal Cellular Beams (ACB)

• Steel connection

True Analysis – Analysis and structural model in parallel

• Work in parallel on the analysis model for the calculation part and on the structural model for the

generation of drawings & connections.

• Priority rules, excentricities, gaps can be added to the analysis model.

• Goal: connection design, automatic generation of overview (GA) drawings and connection detail,

link with CAD software.

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True Analysis – Analysis and structural model in parallel

Implementation of the Eurocodes

• Complete & reliable check of members & connections according to EN1993

• Complete solution for the steel construction: combinations, wind & snow loads, check &

optimisation of members & joints, fire resistance, composite design, etc

Steel code check according to EN1993

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Global approach

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• Stability analysis:• global stability• α critical• decision of 1st or 2nd Order calculation

Global approach

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• Elastic analysis

• α critical > 10 => 1st Order Calculation

• buckling length is based on global buckling mode = equivalent column method

• path a

Global approach

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• α critical < 10 => 2nd Order Calculation

• input of Global Imperfections = equivalent sway method

• path 2a

Global approach

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• Global and Bow Imperfections•path 2c

• path 3

1st Order Calculation

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• α_critical > 10

• User has to do a Stress and Stability check of the structure

• Stress check • Classification on every intermediary section: class1 , class2, class3 or class4• Stress check at every intermediary section with corresponding classification

• Stability check• The critical section classification over the member is used to perform the stability check• Flexural buckling, torsional buckling, lateral torsional buckling, interaction check, battened compression members

2nd Order Calculation

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• α_critical < 10 (elastic analysis)

• Global Imperfection (P – Δ –effects)• Buckling length can be taken equal to system length (= buckling factor is 1)• User has to perform a full Stress and Stability Check• Path 2a

• Global and Local (Bow) Imperfections (P – Δ and P – δ –effects)• Buckling check is already incorporated in the Local Imperfection• Only Stress and LTB check has to be performed• Path 2c

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2nd Order Calculation

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• Global Imperfection (P – Δ –effects)

•Local (Bow) Imperfections (P – δ-effects)

Graphical presentation of imperfections

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Calculation of buckling factors

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• Automatic calculation using General Formula based on • System lengths• Sway / non-sway • VARH-profiles• Crossing diagonals• LTA buckling system

• User input of buckling factor or buckling length

• Calculation of buckling factors using Stability Analysis

Calculation of buckling factors

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Calculation of buckling factors

• General Formula:

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Buckling factors using Stability Analysis

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Buckling factors using Stability Analysis

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Buckling factors using Stability Analysis

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Steel Setup

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• 2nd Order calculation:only section check and LTB check

•If Mcr can be calculated in 2nd Orderonly a section check has to be performed

Steel code check according to EN1993

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Full Example

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• Calculation of α_critical

• 1st Order Calculation: full check

• 2nd Order Caclution:

• Global imperfections according to EN1993

• Local imperfections according to EN1993

Interaction formula EC-EN

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• Adaption of the interaction formula for combined normal and flexural forces Maximal moments are taken

Interaction formula EC-EN

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Additional steel data

• Member buckling data

• Lateral Torsional Buckling restraints

Additional steel data

• Diaphragms

• Stiffeners

Built-up welded sections

• With the rising price of steel, built-up sections become more & more interesting with the gain of

steel weight that they allow

• Scia Engineer supports all possible built-up section, tapered or not, including slender webs (class

4) with the calculation of effective section properties

• The optimisation (AutoDesign) is carried out with user-controlled parameters and methods

Fire resistance

• Fire resistance is always a tricky point for steel structures

• It is supported in Scia Engineer according to the methods in the Eurocode 3

• All the checks are done, under the various possible temperature curves (ISO, petrol fire, natural

fire, etc.) and protection types (none, paintings, gypsum) and allow to guarantee the desired fire

resistance at 30, 60 mins etc

• Possibility to input a self defined Time/Temperature curve

Fire resistance

2nd order lateral torsional buckling

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• 2nd Order Analysis• Applications:

• Calculation of Mcr for non standard sections

• 2nd Order analysis including warping effects

• Diaphragms are calculated on compression and tension flange

• LTB restraints on compression an tension flange

• Exact LTB-analysis for profiles subjected to torsion (e.g.: channel –sections)

2nd order lateral torsional buckling

• For complex cases (tension flanges restrained by the roof, special support conditions, non-

symetrical sections), the formulas given in the codes are not applicable

• Scia Engineer has a specific calculation module for the critical LTB moment Mcr using 7 DOF beam

elements for Euler stability or 2nd order calculation

2nd order lateral torsional buckling

• Mcr calculation in 2nd Order including warping effects:

• LTB does not need to be checked anymore

AutoDesign – Optimisation

• Global optimisation or by beam families (profiles)

• The optimum sections is proposed after a code check (stresses, buckling, LTB, etc)

• Either in a full catalogue or a reduced list

• As well the rolled profiles as the built-up sections or any user-defined section can be optimised

using simple or advanced criterias

Global Autodesign

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Global Autodesign

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ArcelorMittal Cellular Beams (ACB)

• Triple advantadge of aesthetics, holes for technical pipes and large spans

• Cellular beams are more & more used in industrial buildings, parkings, etc

• Scia Engineer incorporates the design of these beams according the the Eurocode provisions

• The deformation is calculated taking into account the

reduced properties near the openings.

Steel connections

Steel connections

• Steel connections: bolted, welded, beam-column, splice, column footing, floor connection, etc• Fixed, pinned and semi-rigid connections• Takes into account the real stiffness of the joint when re-analyzing the structure• Expert system for the search of an optimum connection in the library• Detailed drawing• 100% integrated to the analysis & structural model

Steel connections

CONTENTS:• Connection types• Analysis types and Geometric types• Supported cross-sections

• Column-beam joints

• Moment-Rotation characteristic• Resistance properties• Stiffness properties• Ductility classes• Special features

Steel connections

CONNECTION TYPES:

• Rigid connections:- Transfer of bending moment- Not always completely rigid- Stiffness is calculated by Scia Engineer- Low stiffnesses have to be taken into account

• Pinned connections: No transfer of bending moment

Steel connections: SUPPORTED TYPES OF CONNECTIONS

Analysis types

• Beam-to-column connections :

Bolted endplate + welded connections

(knee, T, cross - with continuous beam

or continuous column)

• Beam-to-beam connections :

Endplate type beam splice

(plate-to-plate connection).

• Column bases :

Bolted base plate connection

shear iron, frange wideners

Steel connections: SUPPORTED TYPES OF CONNECTIONS

Steel connections: SUPPORTED CROSS-SECTIONS

Frame connect: Column-beam joints

Moment-rotation characteristic

General procedure:

Component method to determine stiffness and resistance

• Identification of the active components• Evaluation of S and fi for each component• Assembly of all the components

Frame connect: Column-beam joints

Frame connect: Column-beam joints

Resistance properties

• Equivalent T-stub:

analysis of the endplate bending and

the column flange bending or bolt yielding

3 possible failure modes (picture)

• Use of national code:

DIN, ENV, EN1993 and BS: used for the capacities of the

Underlying steel parts

Other codes: EC3

Frame connect: Column-beam joints

Stiffness properties• The component stiffness

For a column base:

• The stiffness assembly

- Sj,ini is derived from elastic stiffness of the components

- Represented by a spring

- Spring components are combined in a spring model

Frame connect: Column-beam joints

Frame connect: Column-beam joints

• Classification on stiffness

• The required stiffness:

Sj,app = fi y * n

Sj,low <= Sj,ini <=Sj,upper Sj,ini is conform with the applied stiffness in the analysis model

Frame connect: Column-beam joints

Examples:• Bolted connection

• Welded connection

Frame connect: Pinned joints

The following types are supported:

Examples:• Welded fin plate connection

Frame connect: Pinned joints

• Bolted fin plate connection

• Bolted cleat connection

Frame connect: Pinned joints

• Flexible end plate connection