summary - flexural members - lateral torsional buckling
DESCRIPTION
Welding designTRANSCRIPT
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TUTORIAL 5
FLEXURAL MEMBERS
Lateral Torsion Buckling Lateral Torsion Buckling
Summary
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Summary of design process
The design process for a beam can be summarised as follows
(a) Determination of all forces and moments on critical section
(b) Selection of UB or UC
(c) Classification of section
(d) Check shear strength; if unsatisfactory return to (b)
(e) Check bending capacity; if unsatisfactory return to (b) (e) Check bending capacity; if unsatisfactory return to (b)
(f) Check deflection; if unsatisfactory return to (b)
(g) Check web bearing and buckling at supports or concentrated load; if unsatisfactory provide web stiffener
(h) Check lateral torsional buckling; if unsatisfactory return to (b) or provide lateral restraints
(i) Summarise results
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STEP 1: Determine:
VEd - Design Shear Force(Reactions)
MEd - Design Bending Moment( Maximum Moment)
STEP 2: Determine Section ( UB for Beams)
Trial Section: EdM
W = Trial Section:
Classify
STEP 3: Determination of C1 value :
yfEd
y,trialW =
2
1
MM
=
21 52.04.188.1C +=
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STEP 4: Calculation of Mcr(considering the section 2-3):
Lcr Distance between 2 restrained points
STEP 5: Evaluate of reduction factor :General Case( EN 1993-1-1 cl 6.3.2.2)
1
2/1
z2
t2
cr
z
w
2cr
z2
cr C*EIGIL
II
LEI
M
+=
pi
pi
LT
cr
yyLT
MfW
=
( ) ( )[ ]22.015.0 LTLTLTLT ++=
( )[ ] 11
2/12LT
2LTLT
LT +
=
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STEP 5: LTB Resistance(EN 1993-1-1 cl 6.3.2.2 , eq. 6.55):
Depends of the class
STEP 6: Safety Check:
1Mf
WM yy,plLTRd,b =
M1
MM
Rd,b
Ed