7/29/2019 Steel Composite 1 VERY GOOD Mahfuz

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PROJECT: xxxxxxxxxxxxxxxxxxxxxx

Part of Structure: xxxxxxxxxxxxxxxxxxxxx

Beam No.: B1

Designed by: xxxxxxxxxxxxxxxDesign Inf ormation:

Type of construction: Unpropped Simply supported

Beam span: 13.299 m Beam spacing left: 3.600 m

Beam spacing right: 2.878 m

Overall depth of slab Ds: 175 mm Deck: Bondek II profiled sheeting

Profile depth Dp = 54 mm

Shear connectors: Trough spacing = 200 mm

Stud diameter = 19 mm Trough width, average = 168 mm

As-welded length = 95 mm

Concrete: Compressive strength = 30 N/mm2

Density (NWC) = 24 kN/m3

Loading:

Dead load from composite flooring = 4.205 kN/m2

Imposed load on flooring = 15 kN/m2

Construction load (temporary)= 0.5 kN/m2

I ni tial selection of beam size:

Assume span/depth ratio = 20

Beam depth = 664.95 mm

Choose initially 610 X 305 X 179 UB

Ix-x = 151500 cm4 Se = 4907 cm3

Sp = 5515 cm3 A = 228 cm2

Depth = 617.5 mm Beam self weight = 1.79 kN/m

Web thickness = 14.1 mmFlange thickness = 23.6 mm

Steel Grade 43, since T>16, Py = 265 N/mm2

Elasticity modulus = 205 kN/mm2

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7/29/2019 Steel Composite 1 VERY GOOD Mahfuz

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Construction condition:

Design load in construction condition = 24.17 kN/m

Design moment at construction condition = 534.24 kNm

Moment of resistance of steel section = 1461.48 kNm

Moment capacity is O.K.

Check elastic stress due to self weight:

Moment due to self weight = 340.68 kNm

Bending elastic stress = 69 N/mm2

Deflection of soff it of beam after construction:

Deflection = 20.2 mm

This deflection is = Span / 658

Limiting span/deflection ratio = 380

Deflection is O.K.

Composite conditi on - Ul timate load:

Factored load on composite beam = 99.31 kN/m

Ultimate design moment on c.beam = 2195.54 kNm

Dead load support reaction (service) = 102.47 kN

Imposed load support reaction (service) = 323.07 kN

Effective breadth of slab = 3324.75 mm

Resistance of slab in compression = Rc = 5431.0 kN

Resistance of steel section in tension = Rs = 6042.0 kN

Since Rc

7/29/2019 Steel Composite 1 VERY GOOD Mahfuz

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Degree of shear connection:

Number of shear connectors used per trough = 1 Nos.

Number of shear connectors in half span = 33 Nos.

Resistance of shear connectors:

Characteristic strength = 100 kN

Design strength = 0.8x100 = 80 kN

Reduction factor r = 2.01 should be < 1

Therefore take r = 1

Total resistance of shear connectors Rq = 2659.8 kN

Since Rq (L-6)/10, but K > 0.4

Not adequate degree of partial shear connection

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7/29/2019 Steel Composite 1 VERY GOOD Mahfuz

4/5

Composite condi tion - service load:

determine elastic section properties

Modular ratio = 10

r = 0.05667

Elastic neutral axis depth = 235.5 mm, from top of slab

Second moment of area = 4.171E+09 mm4

Elastic section modulus Zt = 7488214.8 mm3

Elastic section modulus Zc = 177120967 mm3

Service load on composite section = 48.59 kN/m

Service moment = 1074.11 kNm

Stress in steel = 143.4 N/mm2

Additional stress on non-comp.section = 69 N/mm2

Total serviceability stress = 212.9 N/mm2

7/29/2019 Steel Composite 1 VERY GOOD Mahfuz

5/5

Check natural f requency of beam:

Weight of floor in dynamic calculations include:

Self weight of slab and beam + 10% imposed load = 20.27 kN/m

Take ratio of the dynamic to static stiffness of a composite beam = 1.1

Deflection-self weight = 8.8 mm

Natural frequency f = 6.08 Hz Satisfactory

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