Steel Structures I. 2nd midterm exam - SAMPLE A Name: - Read very carefully the examples and follow the instructions! - Use this sheet for solving the problems. - Do not forget to give the formula with letters and numbers, as well and give the units. Steel grades: S235 fy = 23,5 kN/cm2 fu = 36,0 kN/cm2 βw=0,80 λ1=93,9 S275 fy = 27,5 kN/cm2 fu = 43,0 kN/cm2 βw=0,85 λ1=86,8 S355 fy = 35,5 kN/cm2 fu = 51,0 kN/cm2 βw=0,90 λ1=76,4 The applied sections do not belong to class 4.

( )M2w

u2II

22

γβfττ3σ⋅

⊥⊥ ≤++ ; M2

u

γfσ ≤⊥ ;

3f

f2Mw

uwd,v

⋅γ⋅β= ; afF wd,vwd ⋅=

M2

ubRdv, γ

Af60F ⋅⋅=

, ; M2

ub1Rdb, γ

tdfαkF

⋅⋅⋅⋅= ;

−⋅=

2,5

7,1de

8,2mink 0

2

1 ;

−⋅=

2,5

7,1dp

4,1mink 0

2

1

⋅

=α 013 0

1 ,;ff;

demin

u

ubb ;

−

⋅= 0,1;;

41

3min

0

1

u

ubb f

fd

pα ;

RdcflRdb MkM ,, ⋅⋅= χ ; 1λ

λ⋅⋅

=fz

ccf

iLk

; 1,1=flk

1. A gusset plate is welded to the lower flange of an I beam and subjected to FEd = 350kN concentric force. a) The welding is partially penetrated butt weld: a = 8 mm. Find the required length of the

welds using the simplified method! b) The welding is fillet weld on both sides of the gusset plate. Check the welded connection, if

mm200= and mma 4= , using the general method! The grade of the steel is S235. 10 points

30°

F Ed

b)a)

10 10

2 Check the bolted connection for FEd = 500 kN tension force! Bolts are M14 5.6 (d0=15mm, fyb=30 kN/cm2, fub=50 kN/cm2), the shear area passes

through the non threaded part. The grade of the steel is S355. 7 points

F

2x200-1260

80200

6550

t = 20 mm60

65 50

F

65

Ed

Ed

t = 22mm 2x300-10

60 75 75 75 60

80

80

140 300

3. Find the lateral torsional buckling resistance of the beam! Use the simplified method! The beam is laterally supported at the supports and in the section of the concentrated force. The beam has a welded section (Class 1), as shown in the Figure. Self weight is ignored. The grade of the steel is S235. 9 points

FEd

6m 1,5

360-12

250-16

250-16

350-8

4 m 1

200-14

200-14