OCUMENT . R CALC-701 0 · accordance with prEN 13474-1. Internal actions of insulating glass units...

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PROJECT ENGINEER

SAMPLE PROJECT IN LONDON

DOCUMENT NO. REVISION

CALC-701 0 TITLE Pages

CURVED GLASS CHECK 55

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SAMPLE PROJECT IN LONDON TITLE REVISION PAGES

CURVED GLASS CHECK 2 of 55


Table of Contents

1 References ............................................................................................................. 3

1.1 Document references .............................................................................................. 3

1.2 Structural analysis software .................................................................................... 3

1.3 Loads ...................................................................................................................... 4

1.4 Design Approach .................................................................................................... 5

1.5 Glass list.................................................................................................................. 6

2 Structural check of curved glass ........................................................................ 7

2.1 GL-05, 07 & 08 (Vision glass) ................................................................................. 7

2.2 GL-09 (Vision glass) ............................................................................................. 22

2.3 GL-14 & 17 (Vision glass) ..................................................................................... 37

3 Annex ................................................................................................................... 53

3.1 PVB Interlayer – Shear modulus .......................................................................... 53

3.2 IGU Edge seal – Technical data sheat ................................................................. 54

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1 References

1.1 Document references

1.1.1 Norms and standards

[1] IStructE. Structural use of glass in buildings. 2nd edition, February 2014.

[2] pr EN 16612:2013. Glass in building – Design of glass panes – Part 1: General basis of design.

[3] pr EN 13474-1:1999. Glass in building – Design of glass panes – Part 1: General basis of design.

[4] BS 6180:1999. Barriers in and about buildings – Code of practice.

[5] CWCT TU14, Technical update on Load combinations

1.1.2 Project specific documents

[6] D262-LFL-SW-TYP-CL-F-1401: Loads and load combinations.

[7] D262-LFL-SW-TYP-CL-F-1540: EWS-203 System framing profiles.

[8] Performance Specification for the Installation of Curtain wall. Rev. M, 24 October 2014.

[9] A Wind tunnel study to determine the wind loads. 24 June 2013.

1.2 Structural analysis software

[10] Nemetschek. SCIA Engineer v.14.0. Structural Analysis & Design Software for Construction and Engineering.

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1.3 Loads

1.3.1 Dead load including selfweights (D)

Glass selfweight is generated by the software.

1.3.2 Wind load (W)

In accordance with load report [6] based on BRE wind tunnel test [9]:

Net pressure, wp = +1.16 kN/m2

Net suction, ws = -1.11 kN/m2

1.3.3 Imposed/live load (L)

In accordance with the load report [6] based on Wintech specification [8]:

i. Residential areas:

Line load, qIh,k = 0.74 kN/m - applied at a height of 1.1m above FFL

Point load, QIh,k = 0.5 kN - applied within a height of 1.1m above FFL

Infill load, wIh,k = 1.0 kN/m² - applied within the infill height of 1.1m above FFL

ii. Retail and general assembly areas:

Line load, qIh,k = 1.5 kN/m - applied at a height of 1.1m above FFL

Point load, QIh,k = 1.5 kN - applied within a height of 1.1m above FFL

Infill load, wIh,k = 1.5 kN/m² - applied within the infill height of 1.1m above FFL

1.3.4 Maintenance load

Manual maintainance on walls according to CWCT clause 2.3.3:

Point load, QIh,k = 0.5 kN - applied on square of 100mm sides

1.3.5 Climatic load (C)

Climatic loads as a result of temperature, atmospheric pressure and altitude difference is checked in

accordance with prEN 13474-1.

Internal actions of insulating glass units

Summer Temperature difference, ΔT [°C] + 27

Pressure difference, Δpmet [kN/m²] - 3.0

Altitude difference, ΔH [m] + 700

Winter Temperature difference, ΔT [°C] - 27

Pressure difference, Δpmet [kN/m²] + 6.0

Altitude difference, ΔH [m] - 400

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1.4 Design Approach

IStructE’s “Structural use of glass in buildings” 2nd edition and the draft European standard for determination of

the load resistance of glass panes prEN 16612 are used as guidance for the following glass structural

calculations.

Design criterion: σd ≤ fg,d

1.4.1 Glass design stress (σd)

FEM analysis of glass panes gives principal stresses to be factored by the partial factors below.

i. Partial factors

Variable action, γQ = 1.2 - for glass used as infills for façade / curtain wall

Variable action, γQ = 1.3 - for secondary structures including infill serving as barrier

Variable action, γQ = 1.5 - for primary structures

Climatic action, ψ0·γQ = 1.0 - accompanying variable load to leading wind or imposed load

1.4.2 Glass design strength (fg,d)

i. Annealed glass

Design bending strength, fg,d = kmod·ksp·fg;k/γM;A

Characteristic bending strength, fg;k - see table below

Load duration factor, kmod - see table below

Glass surface profile factor, ksp = 1.0 - float glass

Material partial factor, γM;A = 1.6 - annealed glass

ii. Prestressed surface glass

Design bending strength, fg,d = kmod·ksp·fg;k/γM;A + kv(fb;k – fg;k)/γM;v

Characteristic bending strength, fb;k - see table below

Strengthening factor, kv = 0.6 - used either for horizontal or vertical toughening

Material partial factor, γM;v = 1.2 - prestressed surface

Allowable stress for vertical glazing infill panel

Float Glass Types

Bending strength

[fg;k, fb;k]

Design Strength [N/mm²]

Wind load*

kmod = 0.74

(W) fg,d

Imposed load only

kmod = 0.89

(L) fg,d

Annealed monolithic 45 20.8 25.0

Heat-strengthened 70 33.3 37.5

Thermally toughened 120 58.3 62.5

Enamelled heat-strengthened 45 20.8 25.0

Enamelled thermally toughened 75 35.8 40.0

Note: * Wind load only or load combination involving wind load.

Thermal stress calculation is not in the scope of this calculation.

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1.5 Glass list

Curved Glass Schedule

Th

ick

ne

ss

Glass Description

Th

ick

ne

ss

Description

Th

ick

ne

ss

Glass DescriptionMin.

Size*

Max.

Size*

[mm] [mm] [mm] [mm×mm] [mm×mm]

1130×1675 2676×1675

1155×1675 1155×1675

1155×1675 1155×1675

820×1378 4800×1855

3670×1998

885×2650 1685×2873

1660×1945 1660×2260

1685×2558 1685×2558

1660×1945 1660×1945Annealed Laminate

Glass16.00

Warm edge black

spacer, silicone

sealed, argon filled

EWS203 (Spec ref

GL101; 102)

R = 1910 mm

(Concave)

43.04 13.52

9 GL-18

EWS203 (Spec ref

GL101; 102)

R = 3300 mm

39.04 11.52

Annealed Laminate

Glass16.00

Warm edge black

spacer, silicone


13.52Annealed Laminate

Glass


Glass

8 GL-17

7 GL-15

EWS203 (Spec ref

GL101; 102)

R = 3300 mm

39.04 11.52

Annealed Laminate

Glass16.00

Warm edge black

spacer, silicone



Glass


Glass

6 GL-14

EWS203 (Spec ref

GL101; 102)

R = 1910 mm

(Concave)

43.04 13.52

Annealed Laminate

Glass16.00

Warm edge black

spacer, silicone


Annealed Laminate

Glass16.00

Warm edge black

spacer, silicone



Glass4 GL-09

EWS206 (Spec ref

GL101; 102)

R = 3910 mm

51.04 17.52

Annealed Laminate

Glass16.00

Warm edge black

spacer, silicone


3 GL-08

EWS205 (Spec ref

GL101; 102)

R = 1840 mm

39.04 11.52

Annealed Laminate

Glass16.00

Warm edge black

spacer, silicone



Glass


Glass

2 GL-07

EWS205 (Spec ref

GL101; 102)

R = 1840 mm

39.04 11.52

Annealed Laminate

Glass16.00

Warm edge black

spacer, silicone



Glass1 GL-05

EWS205 (Spec ref

GL101; 102)

R = 1840 mm

39.04 11.52

Spacer / Gas Space Inner Pane

Ite

m N

o.

Glass Ref.

Wa

ll T

yp

e

Ov

er-

all

th

ick

ne

ss o

f IG

U

Outer Pane

Note: * Glass width are arc length measurements. To get the chord length (C) in terms of arc length (C) and radius of curvature (R) use the formula C = 2R sin[S/(2R)]

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2 Structural check of curved glass

2.1 GL-05, 07 & 08 (Vision glass)

2.1.1 Effective glass thickness, load sharing and climatic loads

prEN 16612:2013 Glass in building - Design of glass panes Clause

Double glazed unit a = 1.675 m Shorter side of DGU

b = 2.676 m Longer side of DGU

d1o + d1i = 5 + 5 mm

t1 = 1.52 mm

16 mm Air space

d2o + d2i = 5 + 5 mm

t2 = 1.52 mm

Effective glass thickness: G = 0.50 N/mm² Shear modulus of interlayer @ 30°C for 10 min. loading

Is1 = 106.28 Stiffness [ASTM E:1300]

Γ1 = 0.3546 Shear transfer coefficient

d1ef ,w = 8.89 mm Effective tickness for deflection (12)

d1ef ,σ = 9.80 mm Effective tickness for stress (13)

Is2 = 106.28 Stiffness




Climatic effects a/b = 0.63 Aspect ratio

k5 = 0.040 Coefficient for volume per load Table B.3

δ1 = d1ef ,w3/(d1ef ,w

3+d2ef ,w3) = 0.500 Factor of load shared by outerleaf glass (C.1)

a* = 28.9(dSZR∙δ1∙d2ef ,w3/k5)

1/4 = 559 mm Characteristic length (C.4)

ϕ = 1/[1+(a/a*)4] = 0.0122 Insulating unit factor (C.3)

Summer: ∆Ts = 27 °K Temperature difference, c 1 = 0.340 kPa/°K

∆pmet,s = -3 kN/m² Difference of meteorological and atmospheric pressure

∆Hs = 700 m Local height difference, c 2 = 0.012 kPa/m

p0,s = c1∙∆Ts - ∆pmet,s + c2∙∆Hs = 20.6 kN/m² Isochore pressure at summer

ps = ϕ∙p0,s = 0.25 kN/m² Effective internal positive pressure

Winter: ∆Tw = -27 °K Temperature difference, c 1 = 0.340 kPa/°K

∆pmet,s = 6 kN/m² Difference of meteorological and atmospheric pressure

∆Hs = -400 m Local height difference, c 2 = 0.012 kPa/m

p0,w = c1∙∆Tw - ∆pmet,w + c2∙∆Hw = -20.0 kN/m² Isochore pressure at winter

pw = ϕ∙p0,w = -0.24 kN/m² Effective internal negative pressure

dSZR ≤

PVB interlayer

Outer laminated glass

PVB interlayer

Inner laminated glass

2.1.2 Glass check

Refer to FEM analysis results in section i.

i. Outer laminted annealed pane - Stress check

Wind load, σd = 2.39 N/mm² < (W) fg,d = 20.8 N/mm²

Imposed load only, σd = 3.56 N/mm² < (L) fg,d = 25.0 N/mm²

ii. Inner laminted annealed pane - Stress check



iii. Deflection check

Max. δ = 0.74 mm < 1675/65 = 25.7 mm

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2.1.3 FEM Analysis

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2.2 GL-09 (Vision glass)





d1o + d1i = 8 + 8 mm

t1 = 1.52 mm

16 mm Air space

d2o + d2i = 8 + 8 mm

t2 = 1.52 mm














a* = 28.9(dSZR∙δ1∙d2ef ,w3/k5)













dSZR ≤

PVB interlayer


PVB interlayer


2.2.2 Glass check

Refer to FEM analysis results in section 2.2.3.

i. Outer laminted annealed pane - Stress check



ii. Inner laminted annealed pane - Stress check




Max. δ = 1.11 mm < 1855/65 = 28.54 mm

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2.2.3 FEM Analysis

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2.3 GL-14 & 17 (Vision glass)





d1o + d1i = 6 + 6 mm

t1 = 1.52 mm

16 mm Air space

d2o + d2i = 6 + 6 mm

t2 = 1.52 mm














a* = 28.9(dSZR∙δ1∙d2ef ,w3/k5)













dSZR ≤

PVB interlayer


PVB interlayer


2.3.2 Glass check

Refer to FEM analysis results in section 2.3.3.

i. Outer laminted annealed pane - Stress check (primary structure glass)



ii. Inner laminted annealed pane - Stress check (primary structure glass)




Max. δ = 9.02 mm < min{2873/175; 15} = 15.0mm

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2.3.3 FEM Analysis

Framed edge with fixing to

mullion of adjacent sliding door

(Refer to D262-LFL-SW-TYP-

CL-F-1540: EWS-203 System

framing report [7])

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Additional linearly distributed suction wind load on

vertical edge of inner pane transmitted from adjacent

flat vision glass GL-13 / 13a.

(Refer to D262-LFL-SW-TYP-CL-F-1540: EWS-203

System framing report [7])

qs,k = 1.11kN/m²·1.8m/2 = 1.0 kN/m

Additional linearly distributed pressure wind load on

vertical edge of inner pane transmitted from adjacent

flat vision glass GL-13 / 13a.

(Refer to D262-LFL-SW-TYP-CL-F-1540: EWS-203

System framing report [7])

qs,k = 1.16kN/m²·1.8m/2 = 1.04 kN/m

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3 Annex

3.1 PVB Interlayer – Shear modulus

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3.2 IGU Edge seal – Technical data sheat

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OCUMENT . R CALC-701 0 · accordance with prEN 13474-1. Internal actions of insulating glass units...

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Transcript of OCUMENT . R CALC-701 0 · accordance with prEN 13474-1. Internal actions of insulating glass units...