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Comparative Study
of Glass Design
StandardsMathieu Meur
November 2017
Comparative Study of Glass Design Standards
▪ Review of glass behaviour
▪ Design standards for glass sheets
▪ Design of glass fins
▪ Design of bolted glass
▪ Beyond standards
Comparative Study of Glass Design Standards
▪ Review of glass behaviour
▪ Design standards for glass sheets
▪ Design of glass fins
▪ Design of bolted glass
▪ Beyond standards
Glass Behaviour
▪ Brittle material
(theory v/s actual)
© University ofTexas Arlington
© E. Premalatha, Dr. C. Umarani
Glass Behaviour
© Gang Deng and Tsutomu Nakanishi
▪ Breakage initiated from micro-cracks
Glass Behaviour
▪ Large deflections –
non-linear
behaviour
© E. Premalatha, Dr. C. Umarani
Glass Behaviour
▪ Behaviour changes
with duration of
loading (creep)
Glass Behaviour
▪ Laminated glass behaviour changes with temperature
Shearmodulus,G(MPa)
20˚C 8.06 1.64 0.840 0.508 0.372 0.266
30˚C 0.971 0.753 0.441 0.281 0.069 0.052
40˚C 0.610 0.455 0.234 0.234 0.052 0.052
50˚C 0.440 0.290 0.052 0.052 0.052 0.052
Poissonratio,v
20˚C 0.4980 0.4996 0.4998 0.4999 0.4999 0.4999
30˚C 0.4998 0.4998 0.4999 0.4999 0.5000 0.5000
40˚C 0.4998 0.4999 0.4999 0.4999 0.5000 0.5000
50˚C 0.4999 0.4999 0.4999 0.4999 0.5000 0.5000
1mo. >1yr.GPVB(MPa)
nPVB 3s 1min. 1hr. 1day 1mo. >1yr.
3s 1min. 1hr. 1day
Glass Behaviour
▪ Laminated glass behaviour changes with temperature
Comparative Study of Glass Design Standards
▪ Review of glass behaviour
▪ Design standards for glass sheets
▪ Design of bolted glass
▪ Design of glass fins
▪ Beyond standards
Glass Design Standards
Standards covered:
▪ ASTM E1300 – US standard
▪ AS 1288 – Australia standard
▪ BS 6262/ 5516 – Bristish standard
▪ TRLV – German technical regulation
▪ prEN 16612/16613 – proposed European standard (not approved)
▪ JGJ 102 – Chinese standard
Glass Design Standards
Other standards not covered:
▪ IS 16231 – India standard – Inspired from AS 1288 and BS 6262
▪ NF DTU 39 – French norm
▪ CAN/CGSB 12 – Canadian standard
▪ NBN S 23-002 – Belgium standard
Glass Design Standards
▪ Focus on structural design aspects
▪ Impact safety not covered
▪ Thermal and visual performance not covered
▪ Aesthetics not covered
Glass Design Standards
▪ Definitions of AN, HS and FT
▪ Deflection limits at centre / edges
▪ Stress limits
▪ Load distribution (laminated / IGU)
▪ Mixed thickness glass consideration
▪ Point-fixed glass consideration
▪ Design of glass fins
▪ Design of curved glass
▪ Design breakage rate
Glass Design Standards – Definitions
ANNEALED GLASS HEAT-STRENGTHENED FULLY TEMPEREDASTM E1300
Residual surface stress near 0Surface compression of 24-52MPa Surface compression >69MPa
AS 1288 ---Surface compressionof 24-69MPa
Surface compression>69MPa
BS 6262/ 5516 --- --- ---TRLV --- --- ---
prEN 16612/16613
Glass which has been treated during manufacture to minimise the residual stress in the glass, allowing it to becut by scoring and snapping
Glass which has been subjected to a strengtheningtreatment, by heat orchemicals, which inducecompressive surface stressinto the whole surface,balanced by tensile stresswithin the body of the glass
Glass which has been subjected to a strengthening treatment, by heat orchemicals, which inducecompressive surface stressinto the whole surface, balanced by tensile stresswithin the body of the glass
JGJ 102---
Surface compressionof 24-60MPa
>90MPa
Glass Design Standards – Definitions
Deflection limitGlass edge
deflection limitUltimate limit
state
ASTM E1300 N.A L/175 Unfactored
AS 1288 L/60 for typical L/180 1.2G+1.5Q
L/30 for cantilevered
BS 6262/ 5516 Min. (L2/125x1000) for <=3m L/125 for monolitic ---
Min. (L2/175x1000+12, 40mm) for >3m L/175 for DGU
Min. (L2/175x1000, 20mm) for DGU
TRLV L/100 min (L/200, 15mm) Unfactored
prEN 16612/16613 min (L/65, 50mm) --- 1.1G+1.2Q
JGJ 102 L/60 L/200 1.2G+1.4Q
Glass Design Standards – Definitions
Allowable stress (MPa)(Short-term load)
Away from edge At edgeAN HS FT AN HS FT
ASTM E1300 23.3 46.6 91.3 18.3 36.5 73AS 1288 c1.[ -9.85ln t +71.34 ] c1.[ -7.88ln t +57.07 ]
c1=1 c1=1.6 c1=2.5 c1=1 c1=1.6 c1=2.5BS 6262/ 5516 --- --- --- --- --- ---TRLV 18 --- 50 --- --- ---prEN 16612/16613 28 49 90.5 --- --- ---JGJ 102 28 56 84 20 40 59
Glass Design Standards – Definitions
Load distribution
Laminated DGU
Short-term load Medium/ long-term load
ASTM E1300 Total thickness --- ---
AS 1288 Total minimum thickness t3/∑ti3 1.25Qt3/∑ti
3
BS 6262/ 5516 --- --- ---
TRLV Total thickness Total thickness t3/∑ti3
prEN 16612/16613 Effective thickness δ1+φδ2
he,SLS= 3√[∑khk
3+12ω(hkh2
m,k)] where δi=hi
3/∑h3;
he,ULS,j = √[he,SLS3/(hj+2ωhm,j
)] φ=1/[1+a/a*]4;a=shorter length of the pane;
a*=28.9[sh13h23/(h13+h23)k5
JGJ 102 te,w= 3√(t13+t23+12ΤIs
) wk,1= 1.1Qt3/∑ti3 (outer lite)
t1e,σ= √[te,w3/(t1+2Τts,2)], Τ=0 for PVB wk,2= Qt3/∑ti
3 (inner lite)
Glass Design Standards – Definitions
Mixed thicknessesfor laminated and DGU
Width : height limitfor 4 sided
Design thickness
ASTM E1300 Yes (for lami only) --- Minimum thickness
AS 1288 Yes 1:5 Minimum thickness
BS 6262/ 5516 No 1:3.5 ---
TRLV Yes --- ---
prEN 16612/16613 Yes --- ---
JGJ 102 Yes (< 3mm) --- ---
Glass Design Standards – Definitions
Design of overhead glass Design of point-fixed glass Design of Glass finASTM E1300 --- --- ---
AS 1288 Angle < 75o to the horizontal --- Fin thickness > 12mm
1.1kN distributed over a circular area of 0.01m2
Friction grip joint for glass fin
Deflection limit L/240
Appendix C for LTB
BS 6262/ 5516 --- Annealed glass is not allowed Fin thickness > 15mm
Glass hole edge distance > 2x thickness
Friction grip joint for glass fin; Bolt spacing > 100mm
TRLV Angle < 80o to the horizontal --- ---
Only laminated for the lower pane
Free edge protrudes < 300mm
prEN 16612/16613 --- --- ---
JGJ 102 ---Thickness > 6mm for flat cap routel
Deflection < L/200
Thickness > 8mm for coutersunk routel
Gap between fin and facial glass >8mm
Edge distant >70mmFin thickness >12mm, breadth > 100mm
Glass Design Standards – Definitions
Climatic loads Design of curved glass Design breakage rateASTM E1300 No No 8 : 1000AS 1288 No Yes 1 : 1000BS 6262/ 5516 No No Not indicated
TRLV Yes Yes pf = 10-6 per year(0.05 : 1000 based on 50 year return)
prEN 16612/16613 Yes Yes Not indicatedJGJ 102 Yes Yes Not indicated
Glass Design Standards – Definitions
0.8x1.8x2=2.88kPa>2kPa
▪ ASTM E 1300
Glass Design Standards – Definitions
Z
X Y
14.2
Global Deformations
|u| [mm]
14.2
12.9
11.6
10.3
9.0
7.7
6.4
5.1
3.9
2.6
1.3
0.0
Max : 14.2
Min : 0.0
IsometricLC 1: Q
Global Deformations u
Factor of deformations: 27.00Max u: 14.2, Min u: 0.0 mm
Z
X Y
Stresses for CO3
x [MPa]
41.573
37.610
33.647
29.684
25.721
21.758
17.795
13.832
9.869
5.906
1.944
-2.019
Max : 41.573
Min : -2.019
IsometricRF-GLASS CA1
Layer No. 1, Bottom
Stresses for CO3 Sigma-x
Max Sigma-x: 41.573, Min Sigma-x: -2.019 [MPa]
▪ AS 1288
Glass Design Standards – Definitions
▪ BS 6262
10mm
Glass Design Standards – Definitions
Z
X Y
Stresses for LC1
x [MPa]
20.540
18.582
16.624
14.666
12.708
10.750
8.792
6.834
4.876
2.918
0.960
-0.998
Max : 20.540
Min : -0.998
IsometricRF-GLASS CA1
Layer No. 1, Bottom
Stresses for LC1 Sigma-x
Max Sigma-x: 20.540, Min Sigma-x: -0.998 [MPa]
Z
X Y
12.9
Global Deformations
|u| [mm]
12.9
11.7
10.5
9.4
8.2
7.0
5.9
4.7
3.5
2.3
1.2
0.0
Max : 12.9
Min : 0.0
IsometricLC 1: Q
Global Deformations u
Factor of deformations: 29.00Max u: 12.9, Min u: 0.0 mm
▪ TRLV
Glass Design Standards – Definitions
Z
X Y
14.0
Global Deformations
|u| [mm]
14.0
12.7
11.5
10.2
8.9
7.6
6.4
5.1
3.8
2.5
1.3
0.0
Max : 14.0
Min : 0.0
IsometricLC 1: Q
Global Deformations u
Factor of deformations: 27.00Max u: 14.0, Min u: 0.0 mm
Z
X Y
Stresses for CO2
x [MPa]
31.632
28.617
25.601
22.586
19.571
16.555
13.540
10.525
7.509
4.494
1.479
-1.536
Max : 31.632
Min : -1.536
IsometricRF-GLASS CA1
Layer No. 1, Bottom
Stresses for CO2 Sigma-x
Max Sigma-x: 31.632, Min Sigma-x: -1.536 [MPa]
▪ JGJ 102
Glass Design StandardsExample Cases
1.5mx3.5m panel in 2kPa withmonolithic heat-strengthened glass
1.6mx3.5m panel in 2.5kPa withlaminated heat strengthened glass
1.4mx3.5m panel in 2.0kPa withDGU heat strengthened glass
ASTM E1300 Glass thickness required = 8mm Glass thickness required = 5+5mm Glass thickness required = 6+6mm
*Deflection limit is not specified *Deflection limit is not specified *Deflection limit is not specified
AS 1288 Glass thickness required = 10mm Glass thickness required = 6+6mm Glass thickness required = 8+8mm
(8mm glass fails in stress) (5+5mm glass fail in stress) (6+8mm glass fail in stress)
BS 6262/ 5516 Glass thickness required = 10mm Glass thickness required = 8+8mm Glass thickness required = 8+8mm
TRLV Glass thickness required = 12mm Glass thickness required = 6+6mm Glass thickness required = 8+8mm
(10mm glass fails in deflection) (5+5mm glass fail in deflection) (6+8mm glass fail in deflection)
prEN 16612/16613 Glass thickness required = 10mm Glass thickness required = 6+6mm Glass thickness required = 6+8mm
(8mm glass fails in stress & deflection) (5+5mm glass fails in stress & deflection) (6+6mm glass fails in deflection)
JGJ 102 Glass thickness required = 10mm Glass thickness required = 8+8mm Glass thickness required = 8+8mm
(8mm glass fails in stress) (6+8mm glass fails in stress) (6+8mm glass fails in stress)
Glass Design Standards
▪ AS 1288 and JGJ 102 generally most comprehensive and
balanced
▪ ASTM E 1300 least conservative
▪ BS 6262 not very comprehensive or flexible
Comparative Study of Glass Design Standards
▪ Review of glass behaviour
▪ Design standards for glass sheets
▪ Design of glass fins
▪ Design of bolted glass
▪ Beyond standards
Design of Glass Fins
▪ Lateral torsional buckling check not covered except in AS 1288
▪ Does not take the non-linear load carrying behaviour due to
imperfections, the glass strength and the interlayer
▪ Also possible to use buckling curves derived from buckling tests
and numerical FEA models
▪ Buckling curves give
reduction factors LT for
design as a function of the
slenderness ratio lLT
© A. Luible
Design of Glass Fins
▪ Lateral torsional
buckling check
𝑀𝐶𝑅 =
𝑔2𝐿𝑎𝑦
𝐸𝐼 𝑦 𝐺𝐽
1.7 × 𝑔3𝑦ℎ𝐿𝑎𝑦
𝐸𝐼 𝑦
𝐺𝐽
Design of Glass Fins
▪ Lateral torsional
buckling restraint
▪ Glass as a restraint?
▪ Restraint capacity?
Design of Glass Fins
▪ Redundancy check –
Laminated glass
▪ Prevent progressive
collapse
▪ Check fins with one
ply broken and
reduced safety
factors (accidental
loading)
Design of Glass Fins
▪ Interstorey
movement
allowance (vertical
restraint release)
© http://www.archello.com
Design of Glass Fins
▪ Spliced connections
© https://www.glassonweb.com
Design of Glass Fins
▪ Spliced connections
Design of Glass Fins
▪ Clamped or bolted design
Design of Glass Fins
▪ Clamped
or bolted
design
Comparative Study of Glass Design Standards
▪ Review of glass behaviour
▪ Design standards for glass sheets
▪ Design of glass fins
▪ Design of bolted glass
▪ Beyond standards
Bolted glass
▪ Stress
concentration
at bolt holes
Bolted glass
▪ Stress concentration at bolt holes
© Mascha Baitinger , Markus Feldmann
Bolted glass
▪ Simple theoretical approach – Multiply stress by a factor
© http://www.fracturemechanics.org
Bolted glass
▪ Simple FEA model – No holes
Bolted glass
▪ Simple FEA model – No holes
Bolted glass
▪ Simple FEA model – No holes
Bolted glass
▪ More refined approach – Hole and fitting
Bolted glass
▪ More refined approach – Hole and fitting
Bolted glass
▪ More refined approach – Hole and fitting
Bolted glass
▪ More refined approach – Hole and fitting
Bolted glass
▪ Stress concentration at bolt holes – Local mesh refinement
© http://www.fracturemechanics.org
Bolted glass
▪ Load amplification factor is inaccurate (over-conservative)
▪ High sensitivity of results to mesh size
▪ Results sensibly the same between simple and complex
models
Comparative Study of Glass Design Standards
▪ Review of glass behaviour
▪ Design standards for glass sheets
▪ Design of bolted glass
▪ Design of glass fins
▪ Beyond standards
Beyond Standards
▪ Direct glass-to-glass
connections
© www.iqglassuk.com
Beyond Standards
▪ Laminated connections
Beyond Standards
▪ Laminated
connections
© EckersleyO‘Callaghan
Beyond Standards
▪ Laminated
connections
© EckersleyO‘Callaghan
Beyond Standards
▪ All glass structures
© EckersleyO‘Callaghan
Beyond Standards
▪ Glued
connections
© EckersleyO‘Callaghan
Beyond Standards
▪ Chemically
tempered glass
© JSJ Jodeit
Beyond Standards
▪ Chemically
tempered glass
© http://www.xinology.com/
Beyond Standards
▪ Glass connections
Comparative Study of Glass Design Standards
▪ Review of glass behaviour
▪ Design standards for glass sheets
▪ Design of glass fins
▪ Design of bolted glass
▪ Beyond standards