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.
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
Global approach Stability analysis: global stability α critical decision of 1st or 2nd Order calculation
Global approach Elastic analysis α critical > 10 => 1st Order Calculation buckling length is based on global buckling mode = equivalent column method path a
Global approach α critical < 10 => 2nd Order Calculation input of Global Imperfections = equivalent sway method path 2a
Global approach Global and Bow Imperfections path 2c path 3
1st Order Calculation 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 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
2nd Order Calculation Global Imperfection (P – Δ –effects) Local (Bow) Imperfections (P – δ-effects)
Graphical presentation of imperfections
Calculation of buckling factors 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 Steel Setup System lengths Member buckling data
Calculation of buckling factors General Formula:
Buckling factors using Stability Analysis Phase 1: Stability calculation Phase 2: Analysis of buckling shape Phase 3: Member buckling data using stability
Buckling factors using Stability Analysis
Buckling factors using Stability Analysis
Steel Setup 2nd Order calculation: only section check and LTB check If Mcr can be calculated in 2nd Order only a section check has to be performed
Steel code check according to EN1993
Full Example 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 Adaption of the interaction formula for combined normal and flexural forces Maximal moments are taken
Interaction formula EC-EN
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 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
Global Autodesign
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