Transcript Slide 1

Steel Connections
Program to calculate steel structures connections
according to EC3 and DIN18800
Theoretic Analysis Overview
The program Steel Connections calculates and designs connections in
steel frames. The analysis and the dimensioning is based upon either
EC3 or DIN 18800.
The theoretic basis of the program covers the following types of joints:
1.
2.
3.
4.
5.
Nominally pinned joints
Rigid joints
Semi-Rigid joints
Full strength joints
Partial strength joints
The program classifies the beam to column joints by their stiffness in:
1. rigid
2. semi rigid and
3. nominally pinned joints.
Steel Connections
Analysis Techniques
Type of joint model
Simple
Continuous
Method of global analysis
All
Elastic
Classification criterion
Used connections
Stiffness
Nominally pinned
Strength
Nominally pinned
Stiffness
Rigid
Nominally pinned
Rigid Plastic
Strength
Full strength
Nominally pinned
Elastic - Plastic
Stiffness
Rigid
Nominally pinned
Strength
Full strength
Nominally pinned
Semi continuous
Elastic
Stiffness
Semi Rigid
Rigid
Nominally pinned
Rigid Plastic
Strength
Partial strength
Full strength
Nominally pinned
Elastic Plastic
Stiffness
Semi Rigid
Rigid
Nominally pinned
Strength
Partial strength
Full strength
Steel Connections
Nominally pinned
Connection Classification
By Stiffness
1. Rigid
2. Semi-rigid
3. Nominally pinned
By Strength
1. Full-Strength
2. Partial-Strength
3. Nominally pinned
Steel Connections
Rotational Stiffness (Sj)
The rotational stiffness of the joint is being determined from the flexibilities
of its basic components each represented by its elastic stiffness coefficient ki.
Ki is the stiffness coefficient for basic joint component i
k eff ,r 
1
1
i k
i ,r
keq 
k
eff ,r
r
zeq
 hr
and
Sj 
Ez2
1

i ki
The results related with rotational stiffness and all the ki coefficients (where
ever needed) appear in the output forms of the program.
Steel Connections
Classification by Stiffness
M
Boundary 1
Zone 1: Rigid
A beam-to-column joint may be
classified as rigid, nominally
pinned or semi-rigid according to
its stiffness, by determining it’s
initial rotational stiffness Sj,ini
M-Φ Diagram
Zone 2: Semi -rigid
Boundary 2
Zone 3: Nominally pinned

Init.Rotat. Stiffness. Sj,ini Braced frames
Unbraced frames
Rigid
Sj,ini > 8 E I b /L b
Sj,ini > 25 E I b /L b
Nominally Pinned
Sj,ini < 0.5 E I b /L b Sj,ini < 0.5 E I b / Lb
Ib/Lb: Ratio of second moment of area of beam to spam of beam
Steel Connections
Classification by Strength
A beam-to-column joint may be classified as full-strength, nominally
pinned or partial strength by comparing its moment resistance with
the moment resistances of the members that it joins.
Full Strength:
Mj,Rd> Mpl,Rd,b
Partial Strength:
Nominally Pinned:
Mj,Rd< Mpl,Rd,b
Mj,Rd < 0.25 Mpl,Rd,b
Steel connection computes Mpl,Rd of beam, and informs the user for the
connection classification according to strength.
Steel Connections
Connection Resistance - Basic Components (1)
The strength of the connection is being calculated using the
strength of the connections components which are named “Basic
Components”.
For the beam to column moment connection
Strength of welded joints
1.
2.
3.
4.
5.
6.
7.
8.
The strength of the
components":
The strength of the
The strength of the
The strength of the
The strength of the
The strength of the
The strength of the
The lever arm (z)
The strength of the
connection is being calculated using the following "basic
column web panel in shear
(Vwp,Rd)
Vwp , Rd
column web in compression
(Fc,wc,Rd)
column web in tension
(Ft,wc,Rd)
column flange in bending
(Ft,fc,Rd)
beam flange and web in compression (Fc,fb,Rd)
beam web in tension
(Ft,wb,Rd)
welds.
Strength of bolted connections
Ft ,wb, Rd 

0.9 f y ,wc AVC
3 * MO
beff ,t ,wb * twb * f y ,wb
 M0
The strength of the connection is being calculated using the previous plus the
following "basic components":
1. The strength of the end plate in bending
(Ft,ep,Rd)
2. The strength of the bolts in tension, in shear and in bearing
3. The lever arm (z).
Steel Connections
Connection Resistance - Basic Components (3)
For the Beam to Column connection with angle cleats
1.
2.
3.
4.
5.
6.
7.
Bolt's resistance in Shear
Cleat's resistance in Bearing
Strength of Cleat in Shear
Strength of Cleat in Rupture
Strength of Beam in Shear
Strength of Beam in Moment
Column's Web in Bearing
For the Foundation Connection
1. Anchor's Resistance in Tension
2. Anchors Resistance in Shear
3. Resist. of Footing Pl. in Bearing
4. Concrete Resistance in Compression
5. Column's Resistance in Compression
6. Footing Plate Resistance in Tension
7. Resistance of The Welds
Steel Connections
Connection Resistance - Basic Components (4)
For the Beam Splice Connection
1.
2.
3.
4.
5.
6.
7.
8.
Bolt's Resistance in Shear
Bolt's Resistance in Bearing
Strength of Bolts in Shear
Strength of flange Plate in Tension
Strength of web Plate in Shear
Welds Resistance of Flange Plate
Strength of plate in rupture
Strength of beam in rupture
For the Tube Splice Connection
1.
2.
3.
4.
5.
6.
7.
Effective Length per Bolt
Resistance in Compression
Resistance in Tension
Resist. of Compressioned Bolt in Shear
Resist. of Tensioned Bolt in Shear
Resistance of Bolt in Bearing
Welds Stresses
Steel Connections
Connection Resistance - Basic Components (5)
For the Truss joint connection with Plate
1. Bolt's resistance in Shear
2. Member's Resistance in Bearing
3. Member's Resistance in Rupture
4. Member's Resistance in Axial
5. Plate's Resistance in Bearing
6. Plate's Resistance in Moment
7. Plate's Resistance in Axial
8. Plate's Resistance in Shear
9. Weld's Resistance in Moment
10.Weld's Resistance in Axial
11.Weld's Resistance in Shear
For the K or N type joint
1.
2.
3.
4.
5.
6.
Resistance
Resistance
Resistance
Resistance
Resistance
Resistance
Steel Connections
in Chord Face Failure
in Brace Failure
of Chord in Shear
in Punching Shear
in Chord's Web Stability
of Chord in Shear NoRd
Equivalent T-stub – Bolted joints
In bolted joints the flange of an equivalent T-stub may be used to model
the resistance of the following basic components:
1. column flange in bending
2. end-plate in bending
3. flange cleat in bending
Steel Connections
Failure modes of actual components
and equivalent T-stub flanges
The “Actual component” the
“Equivalent T-stub” the “Force
diagram” and the “Moment
diagram” are presented for
three different failure modes.
Steel Connections
Note:
It is important to state that this program cannot be used to
check the strength of the members of a steel frame.
The program only checks the member’s components very near
to the connection and it assumes that a member’s check is
already been done.
Steel Connections
The Program
Steel Connections
Main Menu
Command Menu
Main window
Warning Messages
Steel Connections
Current state messages
Support programs
Steel Connections
Ser – Manager
Section
Database
Manipulate all program’s section properties
(change values or add-create user defined sections)
Graphic section’s
representation
Required Data
Steel Connections
Sections
list
DXF output
Simple step generation of dxf files
for every connection.
Scales database
The program can be used undependably from Steel Connections
Steel Connections
Pre-solved connections library (DIN 18800)
Is a very useful feature for searching for a connection that satisfies
specific criteria
Multiple search
criteria
Results presentation
Graphic connection
representation
Steel Connections
Reading Nodes from a SOFiSTiK Database
Select analysis nodes, from a SOFiSTiK
database, to import in Steel Connections.
The selected nodes will be regarded as
connections in the program.
The selection is made graphically.
Steel Connections
Translate Nodes to Connections
The Program tries to
automatically define the
members that take part in the
connection for each node
selected.
If the user wishes to manually change or declare the members that
take part in the connection he must simply right click on the desired
member and select it from the popup menu.
Steel Connections
Reading Loads from a SOFiSTiK Database
Import loads from SOFiSTiK database
Steel Connections
Optimization
(Automatic optimum calculation for the
“Beam to column moment connection”)
Compute maximum
or optional strength
Input loads from
SOFiSTiK databases
Results representation.
Both list and graphical
Manipulation of possible
allowed reinforcements
Design restrictions regarding bolts
(number of rows, type or quality)
Steel Connections
Connection selection
Graphic view
Button selection and details
Steel Connections
Analysis
Steel Connections
Supported Connection Types
Beam to column bolted connection.
Flush or extended end plate configuration
Beam to beam connection
by angle cleats
Apex connection by flush
or extended end plate
Steel Connections
Beam splice
connection
Tube splice
connection
Beam to column
Beam to column connection
welded connection
with angle cleats
Truss joint with
plate
K or N type joints
Foundation connection
with or without shear elements
Data Input
Interactive
Preview Window
Simplified “Input Data” forms
Graphic representation
of all geometric data
Steel Connections
Bolts calculations
Independent
data manipulation
Fully user customized
bolt distances
Automatic bolt
layout generation
Steel Connections
Graphic Results Layout
Representation of most common used results,
according to connection’s elements checks
Ability to handle multiple analysis results,
at the same time, for comparison
Steel Connections
Graphic representations
where ever needed
Connection Classification
According to Stiffness
Zone 1 Boundary
Design Moment-Rotation
Characteristic
Zone 3 Boundary
M-Φ diagram
Initial rotational stiffness of the joint
Steel Connections
Full Results Printout
Ability to produce fully
customizable result files.
The files can be stored
for use in later time, or
either modified with a
simple text editor.
The user have access to all the program’s strength results.
According to the design code used for the analysis (EC3 or DIN18800)
the connection’s "basic components“ strength is presented as well as
all the calculations needed by the design code.
Steel Connections
Example
(Beam to column moment connection)
Dimensioning of the basic components that form the
connections on top left corner of the structure.
The structure was already solved by SOFiSTiK programs.
There is no restriction regarding the analysis type (eg:
elastic, elastoplastic, serviceability, ultimate strength)
Steel Connections
1. Select connection type
2. Add nodes from SOFiSTiK database
Steel Connections
3. Check selected nodes
Steel Connections
4. Add SOFiSTiK loadcases
Presentation of nodes/loadcases
Every kind of loads can be applied to Steel Connections.
There is no restriction regarding analysis type (e.g.
serviceability, ultimate strength, elastic, elastoplastic)
Steel Connections
5. Bolt layout
Steel Connections
6. Results overview
dbl click for more info
Errors regarding strength of basic
component's strength.
The designed connection is not sufficient.
Steel Connections
7. Results evaluation
for every node-loadcase
Steel Connections
8. Automatic correction of connection - Optimization
Steel Connections
9. Optimization results overview
1.
2.
1
1
2
1
Steel Connections
Optimization results
Transfer selected result to
Steel Connections for
further processing
10. Optimized connection’s results overview
No error ratios.
Optimum design –> Ratios close to 1
Steel Connections