1. No category

Metal Structures
Design Project IV
Steel hall
View
Doors - both ends; no column and girts
across; calculation of inside pressure.
Windows - no girts
across.
Structure
Main frames - roof girders and
main columns
Continous purlins
Suspension for purlins
Housing - girts and
columns
Roof bracing
Wall bracing
Sum of sub-structures
Algorithm
Initial drawing
Loads
Purlins
Suspension for purlins
Housing
Roof girder
Main column
Roof bracing
Wall bracing
Joints
Drawing and list of materials
Initial drawing
Loads
The same geometry and location as for II project → the same loads for roofing, snow and
wind on roof
Dead weight of roofing
Dead weight of purlin
Snow
Wind on roof
Wind on wall
Inside pressure
Dead weight of housing
Dead weight of roof girder
Dead weight of main column
Dead weight of bracing and suspension
Imperfections (procedure "A", #18 / 27)
IInd order effect (procedure "A", #18 / 27)
Imposed loads
Thermal actions
Exposed to fire
Accidental actions
Actions durin execution
Purlins
Cold-formed cross-section, continous
beam with suspension.
Exact calculations: 1993-1-3
Aproximation: I, II or III clas of crosssection, non-symmetrical cross-section
Class of cross-section
Shear resistance
Bi-axial bending
Deflections
Main axes are not parallel and
perpendicular to surface of roof
→ #7 / 35
"Normal" purlin - in both direction the same length
→ #7 / 36
Suspended purlin - addidtional support on y-direction.
For x-z - the same length
For x-y l1 = l / 2;
Mmax ≈ 1 / 4 previous value;
fmax ≈ 1 / 16 previous value;
Housing columna and girts
RHS
Girts
Class of cross-section
Shear resistance
Bi-axial bending
Deflections
Housing columns
Class of cross-section
Shear resistance
Bending and axial force with flexural buckling
Deflection
I-beam column - interaction
between flexural bucklin and
lateral buckling
RHS column - flexural
buckling only
Roof girder
IPE, HEA, HEAA
Class of cross-section
Shear resistance
Bending and axial force
Interaction flexural buckling lateral buckling
Deflection
µy = µz = µLT = 1,0
Lcr, y = Lg
Lcr, z = Lb
Lcr, LT = max (Lb ; Lc)
y - in plane; z - out of plane
Resistance for bending and axial force - MEd i NEd for analysed cross-section.
Interaction flexural buckling - lateral buckling - MEd i NEd max for analysed member,
even if they are in different cross-sections.
Main columns
IPE, HEA, HEAA
Class of cross-section
Shear resistance
Bending and axial force
Interaction flexural buckling - lateral buckling
Deflection
µy → W. Bogucki, M. Żyburtowicz
µz = µLT = 1,0
Lcr, y = Lcr, z = Lcr, LT = H
y - in plane; z - out of plane
Buckling length factor in-plane of frame
"Tablice do projektowania konstrukcji metalowych", W. Bogucki, M. Żyburtowicz, Arkady,
Warszawa 1984
Roof bracings
●L
Prevention of flexural buckling
and lateral buckling of girders;
Wind pressure on front wall;
Example 4
Horizontal upper transversal bracings I-beam
girders
Wind from this part acts
on roof bracings
(approximation)
→ #15 / 58
Wall bracings
●L
Sway imperfection of columns
Wind pressure on front wall
Example 5
Vertical wall bracings
F = Fwind + Fcolumn-imperf
Wind from this
part acts on left
wall roof bracings
Wind from this
part acts on right
wall roof bracings
→ #15 / 60
Joints
purlin-purlin: rigid, bolted
purlin-girder: hinge, bolted and welded
girt - column: hinge, bolted
girt - housing column: hinge, bolted
housing column - girder: hinge, bolted
base plate of housing column: hinge, bolted and welded
roof bracing - girder: hinge, bolted and welded
wall bracing - column: hinge, bolted and welded
base plate of column: hinge, bolted and welded
column - column: rigid, bolted
girder - girder: rigid, bolted
girder - girder (ridge): rigid, bolted and welded
column - girder: rigid, bolted and welded
Joint column-girder
• Stiffeness of the joint
• Welds between roof girder and end plate
• Bolted joint girder - column; bedning moment
• Bolted joint girder - column; shear force
Stiffeness of the joint
Calculations according to elastic model
Rigid
→ #20 / 24
Semi-rigid
Pinned
EN 1993-1-8 fig 5.4
Example 3
Filled welds
Welds between end-plate and girder or between base plate and column or between girder and
column
→ #9 / 23
We should take into consideration no more than three rows of bolt in tensed part of node.
Although it we should applied rows through whole high of beam for category E.
→ #12 / 32
1st row of bolts:
Beam flange and beam web in compression (BFC) → #t / 6
Column web in transverse compression (CWC) → #t / 7
Column web in shear (CWS) → #t / 16
→ #12 / 33
Column web in tension, 1st row (CWT1) → #t / 17
We analyse only bolt-row considered individually (i) (→ #11 / 75 ~ #11 / 77). We must
analyse circular (c) and non-circular (nc) patterns (→ #11 / 73):
CWT1-i-c, CWT1-i-nc
Beam web in tension 1st row (BWT1) → #t / 17
There is no web, but this gusset plate will be treated as web. We analyse only bolt-row
considered individually (i) (→ #11 / 75 ~ #11 / 77). We must analyse circular (c) and noncircular (nc) patterns (→ #11 / 73):
BWT1-i-c, BWT1-i-nc
3rd row of bolts continuation:
Resistance for third bolt-row:
→ #12 / 44
3BR = min [ BFC ; CWC ; CWS ; CWT3-i-c ; CWT3-i-nc ; ( CWT3-23g-c – 2RB ) ;
( CWT3-23g-nc – 2RB ) ; ( CWT3-123g-c – 1RB – 2RB ) ; ( CWT3-123g-nc – 1RB – 2RB ) ;
BWT3-i-c ; BWT3-i-nc ; ( BWT3-23g-c – 2RB ) ; ( BWT3-23g-nc – 2RB) ;
CFB3-i-c-1 ; CFB3-i-c-2 ; CFB3-i-c-3 ; CFB3-i-nc-1 ; CFB3-i-nc-2 ; CFB3-i-nc-3 ;
( CFB3-23g-c-1 – 2RB ) ; ( CFB3-23g-c-2 – 2RB ) ; ( CFB3-23g-c-3 – 2RB ) ;
( CFB3-23g-nc-1 – 2BR ) ; ( CFB3-23g-nc-2 – 2RB ) ; ( CFB3-23g-nc-3 – 2RB ) ;
( CFB3-123g-c-1 – 1RB – 2RB ) ; ( CFB3-123g-c-2 – 1RB – 2RB ) ;
( CFB3-123g-c-3 – 1RB – 2RB ) ; ( CFB3-123g-nc-1 – 1RB – 2RB ) ;
( CFB3-123g-nc-2 – 1RB – 2RB ) ; ( CFB3-123g-nc-3 – 1RB – 2RB ) ;
EB2-i-c-1 ; EB2-i-c-2 ; EB2-i-c-3 ; EB2-i-nc-1 ; EB2-i-nc-2 ; EB2-i-nc-3 ;
( EB2-23g-c-1 – 2RB ) ; ( EB2-23g-c-2 – 2RB ) ; ( EB2-23g-c-3 – 2RB ) ;
( EB2-23g-nc-1 – 2RB ) ; ( EB2-23g-nc-2 – 2RB ) ; ( EB2-23g-nc-3 – 3RB )]
Resistance of joint:
→ #12 / 45
Mj, Rd = 1RB · z1 + 2RB · z2 + 3RB · z3
Mj, Ed / Mj, Rd ≤ 1,0
Shear force – acts on bolts in compressed part of joint
Thank you for attention
© Tomasz Michałowski, PhD
tmichal@usk.pk.edu.pl