Steel construction highlights

1
Steel construction highlights

• A complete steel solution in Scia Engineer

2
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

3
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.

4
True Analysis Analysis and structural model in
parallel
5
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

6
Steel code check according to EN1993
7
Global approach

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

8
Global approach

• Elastic analysis
• a critical gt 10 gt 1st Order Calculation
• buckling length is based on global buckling mode
  equivalent column method
• path a

9
Global approach

• a critical lt 10 gt 2nd Order Calculation
• input of Global Imperfections equivalent sway
  method
• path 2a

10
Global approach

• Global and Bow Imperfections
• path 2c
• path 3

11
1st Order Calculation

• a_critical gt 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

12
2nd Order Calculation

• a_critical lt 10 (elastic analysis)
• Global Imperfection (P ? 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 ? and
  P d effects)
• Buckling check is already incorporated in the
  Local Imperfection
• Only Stress and LTB check has to be performed
• Path 2c

13
2nd Order Calculation

• Global Imperfection (P ? effects)
• Local (Bow) Imperfections (P d-effects)

14
Graphical presentation of imperfections
15
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

16
Calculation of buckling factors
17
Calculation of buckling factors

• General Formula

18
Buckling factors using Stability Analysis
19
Buckling factors using Stability Analysis
20
Buckling factors using Stability Analysis
21
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

22
Steel code check according to EN1993
23
Full Example

• Calculation of a_critical
• 1st Order Calculation full check
• 2nd Order Caclution
• Global imperfections according to EN1993
• Local imperfections according to EN1993

24
Interaction formula EC-EN

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

25
Interaction formula EC-EN
26
Additional steel data

• Member buckling data
• Lateral Torsional Buckling restraints

27
Additional steel data

• Diaphragms
• Stiffeners

28
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

29
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

30
Fire resistance
31
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)

32
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

33
2nd order lateral torsional buckling

• Mcr calculation in 2nd Order including warping
  effects
• LTB does not need to be checked anymore

34
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

35
Global Autodesign
36
Global Autodesign
37
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.

38
Steel connections
39
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

40
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

41
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

42
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

43
Steel connections SUPPORTED TYPES OF CONNECTIONS
44
Steel connections SUPPORTED CROSS-SECTIONS
45
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

46
Frame connect Column-beam joints
47
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

48
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

49
Frame connect Column-beam joints
50
Frame connect Column-beam joints

• Classification on stiffness
• The required stiffness
• Sj,app fi y n
• ? Sj,low lt Sj,ini ltSj,upper ? Sj,ini is conform
  with the applied stiffness in the analysis model
  

51
Frame connect Column-beam joints

• Examples
• Bolted connection
• Welded connection

52
Frame connect Pinned joints

• The following types are supported
• Examples
• Welded fin plate connection

53
Frame connect Pinned joints

• Bolted fin plate connection
• Bolted cleat connection

54
Frame connect Pinned joints

• Flexible end plate connection