Tiêu chuẩn iso 01288 2 2016

© ISO 2016 Glass in building — Determination of the bending strength of glass — Part 2 Coaxial double ring test on flat specimens with large test surface areas Verre dans la construction — Déterminati[.]

Glass in building — Determination of

Par t 2:

Coaxial double-r ing test on flat

Ve r da s la co struction — Déte mination de la résista c du ve r

à la fle xion —

Partie 2: Essais a e do ble s a nea x co c ntrique s sur é ro vet e s

pla e s, a e de gra de s surf c s de solicitation

Fir t edition

2 16-0 -1

Refer ence n mb r

ISO 1 8 -2:2 16(E)

COPYRIGHT PROTECTED DOCUMENT

© ISO 2016, P blshed in Sw itz rlan

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F reword i v

1 Sc ope 1

2 Nor mati ve r eferenc es 1

3 Terms and definitions 1

4 Symbols 2

5 Principle of test metho 2

6 A pparatus 3

6.1 Tes ing machine 3

6.2 L ading devic 4

6.2.1 R ing lo d 4

6.2.2 Surfac pr es ur e reg ulator 4

6.3 Measuring ins rument 5

7 S mple 5

7.1 Sha e an dimensions ofthe spe imens 5

7.2 Sampl ng an pr eparation of spe imens 5

7.2.1 Cutting an han l ng 5

7.2.2 C n itioning 5

7.2.3 Examination 6

7.2.4 A dhesive fim 6

7.3 Numbe of spe imens 6

8 Proc ed re .6

8.1 Temperatur e 6

8.2 Humidity 6

8.3 Thicknes measur ement 6

8.4 Base plate 6

8.5 Positioning of spe imen an lo ding ring 6

8.6 L ad a plcation 7

8.7 L ading rate 7

8.8 L cation of the orig in 7

8.9 A sses ment of resid al s r es es 7

9 Evaluatio 8

9.1 Limitation of the ev luation 8

9.2 Calculation of ben ing s r eng th 8

10 Test rep rt 9

A nne x A (informative)Example of a devic e for ke ping the gas pr es ure, p, in lne with the pisto forc e, F 11

Biblog raphy 14

ISO (he Int ernational Org nization for Stan ardization) is a worldwidefede ation of national s an ards

b dies (ISO membe b dies) The work of pr p ring Int ernational Stan ards is normaly car ied out

through ISO t ech ical committ ees Each membe b dy int er st ed in a subje t for w hich a t ech ical

committ ee has be n es a lshed has the right t o be r pr sent ed on that committ ee Int ernational

org nizations, g ove nmental an non-g ove nmental, in laison with ISO, also take part in the work

ISO cola orat es closely with the Int ernational Ele trot ech ical C mmis ion (IEC) on al matt ers of

ele trot ech ical s an ardization

The proc d r s used t o develo this document an those int en ed for it furthe maint enanc ar

desc ibed in the ISO/IEC Dir ctives, Part 1 In p rticular the dife ent a pro al c it eria ne ded for the

dife ent ty es of ISO document should be not ed This document was draft ed in ac ordanc with the

edit orial rules of the ISO/IEC Dir ctives, Part 2 ( e www.iso.org dir ctives)

A tt ention is drawn t o the p s ibi ity that some of the element of this document ma be the subje t of

p t ent right ISO shal not be held r sp nsible for identifying any or al such p t ent right Detais of

any p t ent right identified d ring the develo ment of the document wi be in the Introd ction an / r

on the ISO ls of p t ent de larations r c ived ( e www.iso.org p t ent )

Any trade name used in this document is information given for the convenienc of use s an does not

cons itut e an en orsement

F or an ex lanation on the meaning of ISO spe ific t erms an ex r s ions r lat ed t o conformity

as es ment, as wel as information a out ISO’ s adhe enc t o the WTO principles in the Te h ical

Bar ie s t o Trade (TBT) se the fol owing URL: F or word - Sup lementary information

The committ ee r sp nsible for this document is ISO/TC 1 0, Glas s in b idin , Subcommitt ee SC 2, Use

c ons ide atio s

ISO 1 88 consis s of the folowing p rt , un e theg ene al title Glas s in b idin — Dete min tio o the

bendin s tr n th o glas s:

— Part 1: Fu damentals o tes tin glas s

— Part 2 : Co xial do ble rin tes t o flat s pec imens w ith large tes t s urf ce ar as

— Part 3 : Tes t w ith s pec imen s up orted at t wo p ints (fur p int bending )

— Part 4 : Tes tin o cha nel sh ped glas s

— Part 5: Co x ial do ble rin tes t o flat s pec imens w ith s mal tes t s urfc e ar as

Glass in building — Determination ofthe bending

Part 2:

Coax ial double-ring test on flat specimens with lar g e test

This p rt of ISO 1 8 spe if ies a method for det ermining the ben ing s r ngth of glas for use in

bui dings, ex clu ing the efe t of the edg es

The l mitations of this p rt of ISO 1 8 ar desc ibed in ISO 1 88-1

2 Normati ve r eferences

The folowing document , in w hole or in p rt, ar normatively r fe enc d in this document an ar

in ispensa le for it a pl cation F or dat ed r fe enc s, only the edition cit ed a pl es F or u dat ed

r fe enc s, the lat es edition of the r fe enc d document ( inclu ing any amen ment )a pl es

ISO 48, Ru be , v ulc ani zed or thermo las ic — Determin tion o h rdnes (h rdnes s betwe n 10 IRHD

a d 10 IRHD)

ISO 1 8 -1, Glas s in b idin - Dete min tio o the bendin s tr n th o glas s - Part 1: Fu damentals o

tes tin glas s

3 Terms and definitions

F or the purposes of this document, the folowing t ermsand definitions a ply

3.1

bending stres

t ensie ben ing s r s in uc d in the surfac of a spe imen

Note 1t o entry: For testing p rposes, the b n ing stres should b u iform over a specif ied part of the surface

3.2

efective bending stres

weight ed a e ag e of the t ensi e ben ing s r s es, calculat ed b a plying a fact or t o take int o ac ou t

non-uniformity of the s r s field

3.3

bending strength

t ensie ben ing s r s or efe tive ben ing s r s w hich leads t o br akag e of the spe imen

3.4

equivalent bending strength

a par nt ben ing s r ngth of p tt erned glas , for w hich the ir egularities in the thick es do not alow

pr cise calculation of the ben ing s r s

4 Symbols

2

E mod lus of elas icity (Young’ s mod lus) ofthe spe imen

NOTE F or soda lme si cat e glas ( e ISO 1 2 3-1), a v lue of 7 GPa isused

Pa

F

ma

F

ring

for e transmitt ed b the lo ding ring t o the spe imen, “ ring lo d” N

NOTE F or soda lme si cat e glas ( e ISO 1 2 3-1), a v lue of 0,2 isused

p

ma

( F

ma

r

1

r

2

r

3m

σ

b

σ

beq

F *, p*, σ* non-dimensional q antities cor esp n ing to F, p an σ [se Form ulae (1) to (5)]

5 Principle oftest method

The sq ar spe imen, of side length, L, an ha ing virtualy plain p ralel surfac s, is plac d lo sely

on a sup orting ring (a cir ular ring with a radius r

2 ) The spe imen is subje t ed t o a lo d, F

ring , b

means of a lo ding ring (radius r

1 ), w hich is ar ang ed conc ntrical y t o the supp rting ring In ad ition,

the ar a, A, defined b the lo ding ring 0 < r < r

1

is plac d un e g s pr s ur , p, w hich has a spe ific

r lationshipwith the ring lo d, F

ring ( e Figur 1)

When the spe imen is subje t ed t o the ring lo d an the as ociat ed g s pr s ur , depen ing up n

the dimensions r

1 , r

2 , L, an h, a radial t ensi e s r s field, w hich is suff iciently homog eneous for the

t es purp se, is develo ed on the convexly bent surfac o e the ar a defined b the lo ding ring ( e

R efe enc s [2], [3], [4]) The tang ential t ensie s r s is eq al t o the radial t ensie s r s at the c ntral

point r = 0)of the spe imen, but de r ases asthe radius, r, inc eases

Out ide the lo ding ring, the radial an tang ential s r s es fal sharply t owards the edg e of the

spe imen, so that the risk of br akag e out ide thelo ding ring is low On the edg e of the spe imen it elf,

the radial s r s is z ro an the tang ential s r s is a compr s ive s r s , this being the caseon b th the

conca ely an the convexly bent sides of the spe imen The edg e of the spe imen is th s alway s un e

tang ential compr s ive s r s ( e ISO 1 8 -1)

By inc easing thefor e, F, an the g s pr s ur , p, the t ensie s r s in the c ntral part of the spe imen

is inc eased at a cons ant rat e [se (6.1 b)] u ti br akag e, so the origin of the br ak can be ex e t ed t o

oc ur in the surfac ar a subje t ed t o ma imum t ensie s r s within the lo ding ring

W ith the t es a p ratus as shown in Figur 1, a for e, pA, act a ains the pist on for e, F, d e t o the g s

pr s ur , p The for etrans e r d b the lo ding ring is F

ring

= F- pA Th s a dis inction should be made

betwe n the pist on for e an the ring lo d

The ben ing s r ngth, σ

b , or eq iv lent ben ing s r ngth, σ

beq , is calculat ed from the ma imum

v lue, F

ma

, of the pist on for e, measur d at the time of br akag e, and thethicknes , h, of thespe imen,

taking int o ac ou t the pr sc ibed dimensions of the spe imen and v rious charact eris ic mat erial

v lues This as umes that the g s pr s ur , p, fol ows the pist on for e, F, ac ording t o the nominal

fu ction p( F), ( e Figur 3)

6 A pparatus

6.1 Testing machine

The ben ing t es shal be car ied out using a suita le ben ing t es ing machine, w hich shal incorp rat e

the folowing featur s

a) The s r s ing of the spe imen shal be ca a le of being a pled from z ro up t o a ma imum v lue in

a manne w hich minimiz s shock an is st eples

b) The s r s ing devic shal be ca a le of the spe ified rat e of s r s ing

c) The t es ing machine shal incorporat e a lo d measuring devic with a l mit of e ror of ± ,0 % within

themeasuring rang e

Key

1 lo ding ring

2 specimen

3 su porting ring

Figure 1 — Basic dia ram of test apparatus

1 specimen

2 rig id b se plate, preferably made of ste l, w ith su porting ring (radius r

2 ) a

3 rub er pr ofile, adapted to the su porting ring , 3 mm thick, w ith a hardnes (40 ± 1 )IR HD (in ac or dance w ith

ISO 48)

4 rig id lo ding ring (r adius r

1 ), pr eferably made of ste l

a

5 force transmitting componen w ith a b l mechanism to ensure the for ce is centr ed in the lo ding ring

6 rub er pr ofile, adapted to the lo ding ring , 3 mm thick w ith a hardnes (40 ± 1 ) IR HD (in ac or dance w ith

ISO 48)

b

7 adjustment jaws for centring the specimen

c

8 contact cir cle of the lo ding ring

9 contact cir cle of the su porting ring

a

T e radius of curvatur e of the b aring surface of the ring is 5mm

b

In the case of specimens which ar e patterned on the lo ding ring side, a spong e rub er pr ofile ap r ox imately

5 mm thick should also b used to ensure an adeq ate se l for the gas pres ur e

c

T e jaws ar e r emoved b for e the b n ing test is started, in or der that the edg e of the specimen is not clamped

Figure 2 — Loading device

6.2 Loading devic e

6.2.1 Ring load

The ring lo d shal be a pled using a lo ding devic as shown in Figur 2 The dimensions of the lo ding

devic ar given in Ta le 1

Table 1 — Dimensio s for the loading ring and sup orting ring

Dimensions in mil imetr es

L ading ring r

1

Sup orting ring r

2

Efe tive surfac ar a

mm 2

6.2.2 Sur fac e pr es ure reg ulator

The lo ding devic for the surfac pr s ur is shown in Figur 2

The r gulat or shal be chosen with r g rd t o ac uracy and flow rat e in such a wa that the nominal

fu ction, p( F), as shown in Figur 3 or Ta le 3, can be met se An ex A)

6.3 Measuring instr uments

The folowing measuring ins rument ar r q ir d:

— a measuring ins rument ena lng the width of the spe imen t o bemeasur d t o the near s 1mm;

— a measuring ins rument alowing the thick es ofthe spe imen to be measur d to the near s 0,0 mm

7.1 Shape and dimensions of the specimens

Sq ar spe imens of the dimensions shown in Ta le 2 shal be used

The minimum thicknes given for the spe imens has be n calculat ed in such a wa that he efe t of the

self-weight of the spe imen upon the s r s dis ribution can be ignor d

Table 2 — Dimensions of specimens

Dimensions in mil imetr es

Specimen side length L Minimum nominal specimen

thick es

Avera e specimen radius (for

evalu-ation)r

3m

The folowing t ole anc sfor the spe imens shal be o se ved

In the case of spe imenswith flat surfac s:

— the evennes t ole anc shal be 0,3 mm;

— the paralel sm t ole anc shal be2 % of the spe imen thick es

In the case of spe imenswith one or two p tt erned surfac s:

— the fluctuations of the plat e thicknes ( e 8.3)shal be not mor than 4 % an the local deviations

from the averag e thick es (d e t o the depth of the p tt ern) shal be a ma imum 3 % or 2 mm,

w hicheve is the lowe

7.2 S mpl ng and pr eparation of specimens

7.2.1 C t ing and handlng

The gr at es car shal be taken that the t es surfac , w hich wi be subseq ently subje t ed t o t ensi e

s r s , does not come int o contact with t ools, grin ing ag ent , glas spl nt ers, et c an also is not

damag ed d ring st orag e

NOTE 1 In order t o preserve specif ic surface con itions, the t est surface can b provided with a protective

co ting (glued down)d ring specimen preparation

NOTE 2 T e method of cut ing specimens is not signif icant an no edg proces ing is neces ary

7.2.2 C nditio ing

Prot ectiveco tings shal be r moved 24 h befor the t es ( e ISO 1 8 -1) The spe imen shal be st or d

in the t es environment ( e 8.1 an 8.2) for at leas 4 h befor t es ing

7.2.3 Examination

Befor the ben ing s r ngth t es , al spe imens shal be ex mined o e the t es surfac ar a for any

fa ult w hich ar not r pr sentative of the q alty charact eris ics of the mat erial t est ed

7.2.4 Adhesi ve fim

To hold t og ethe the fra ment , an ad esive film shal be fix ed t o the side of the spe imen facing the

lo ding ring This faci tat es location of the fractur origin and measur ment of the spe imen thick es

7.3 Number of specimens

The n mbe of spe imens t o be t est ed shal be det ermined depen ing on the conf idenc lmit r q ir d,

espe ialy with r g rd t o es imating the extr mes ofthe s r ngth dis ribution ( e ISO 1 8 -1 for a

discus ion of n mbe s of spe imens)

8 Proc edure

The co xial ring ben ing t es shal be car ied out at a t empe atur of (2 ± 5) °C During the t es ,

the tempe atur of the spe imen shal be kept cons ant t o 1 °C, in orde t o avoid the develo ment of

the mal s r s es

8.2 Humidity

The co xial ring ben ing t es shal becar ied out at a r lative h midity betwe n 40 % an 7 %

Sinc the nominal pr s ur fu ction, p( F), in ac ordanc with Figur 3 or Ta le 3, is depen ent up n

the spe imen thick es , h, this shal be det ermined befor s arting the t es

F or this purp se, the thick es shal be measur d at a minimum of eight point on the edg e of the

spe imen F or spe imens with one or two ornamental surfac s, both the plat e thick es an the cor

thicknes shal be measur d The a e ag e is taken from al these measur d v lues

The v alue o tained in this w a y for the spe imen thick es or the eq iv alent spe imen thick es , h, is used

to determine the nominal pr s ur fu ction, p(F ) By measuring the thick es on the edge of the spe imen,

u desira le damage to the surfa ce ca used b measuring tools does not afe t the fractur beha viour

8.4 Base plate

The b se plat e is c ntr d b mo ing down the for e transmit ing component (without the lo ding ring

an spe imen)int o the adjus ing cone ( e Figur 2) The b se plat e shal be fix ed in this p sition Glas

splnt ers an othe hard an sharp-edg ed p rticles shal be cleaned from the sup orting ring Damag e

t o thesup orting ring shal beel minat ed

8.5 Positioning of specimen and loading ring

The spe imen is p sitioned with the surfac t o be t est ed downwards The lo ding ring, from w hich

glas splnt ers an othe hard an sharp-edg ed particles ha e be n r mo ed, is plac d on the up e

side of the spe imen and c ntr d The rub e conne tion at ached t o the lo ding ring shal be che ked

for it sealng efe t an if ne es ary r plac d Damag e t o the lo ding ring shal be elminat ed