Belis, Jan

Callewaert, Dieter

Delincé, Didier

Depauw, Jeffrey

Van Impe, Rudy

English

Ghent University Academic Bibliography

Failure behaviour of glass laminates with a "stiff" interlayer at room temperature

Belis, JanTW140019933828378010012923790000-0001-9248-2171F590F15C-F0ED-11E1-A9DE-61C894A0A6B4

Depauw, JeffreyUGent6DF40CF2-B25E-11E6-B104-2D2FD0AF0289

Delincé, DidierUGent000060748874802000122294976281720909F8ACDDF6-F0ED-11E1-A9DE-61C894A0A6B4

Callewaert, DieterUGent002000355925802000037523F8571312-F0ED-11E1-A9DE-61C894A0A6B4

Van Impe, RudyUGent801000386643979193940185F3E7E130-F0ED-11E1-A9DE-61C894A0A6B4

Archivsystem Ask23

Laboratory for Research on Structural Models - Department of Structural Engineering - Ghent UniversityTechnologiepark-Zwijnaarde 904B-9052 Zwijnaarde (Gent)BelgiumT: +32 (0)9 264 54 70F: +32 (0)9 264 58 38E:http://www.lmo.UGent.beFAILURE BEHAVIOUR OF GLASS LAMINATES WITH A “STIFF” INTERLAYER AT ROOM TEMPERATUREJ. Belis, J. Depauw, D. Delincé, D. Callewaert, R. Van ImpeLMO – DD/JB – 07/08roblem statementPJan.Belis@UGent.beAcknowledgementsResearch Foundation – Flanders (FWO)for the financial supportDuPont de Nemours Belgium / Lerobelfor the test samples“It should not break, but what if it does ?”Consequence versus probability of glass breakagezzL QL F L L F LA Lt Q In construction industry, laminated glass is used more and more for transparent load-bearing building components such as glass floors, stair steps, beams, etc. The choice of the interlayer used to bond the different glass panes one to another is known to affect the post-breakage behaviour, namely the residual load bearing capacity after breakage of one or more glass sheets. However, no validated and generally accepted model currently exist to be used for practical purposes. In particular, for the design of non-standard structural applications, full-scale validation tests are often necessary, but shortages remain, among others due to the sensitivity of the post-breakage behaviour to the temperature and to the load duration. Besides the most often used interlayer polyvinyl butyral (PVB), other interlayer products are developed that could provide better post-breakage performances. One of those is the SentryGlas® Plus (SGP) of Dupont de Nemours, known to be stiffer than PVB. The current research aims to better characterize the interlayer and adhesion properties for modeling purposes of the post-breakage behaviour of laminated glass.reliminary test resultsPext steps...NFour-points bending testsThe tests focus on the post-breakage behaviour in bending around the weak axis of laminated glass plates made of 2 floatglass sheets of 8 mm, bonded by a single SGP-interlayer of 1.52 mm, with a length of 1100 mm and different widths.The main outcomes of those tests are the identification of important mechanisms ruling the failure behaviour, namely : Material propertiesMechanical behaviour of interlayersinvestigated with standard uniaxialtensile tests (ISO 527).Limitations : • occurence of necking neglected• sample geometry dependency• carried only at room temperatureeferencesRQualitative results for (nominal) stress-strain curves :• PVB (T≥Tg=15-18°C) : (viscoelastic) hyperelasticbehaviour typical of rubber state (almost fully reversibledeformations)• SGP (T<Tg=55-60°C) : elasto-visco-plastic behaviourtypical of glassy state (important plastic deformation).(Tg: glass-transition temperature, T: room temperature) C Stage IT Stage IIC T C T Stage IIICT 1. the stretching of the interlayer under tensile force, eventually up to rupture; 2. the delamination (debonding) be-tween the glass pieces and the interlayer mainly under shear stress; 3. the splitting up of the glass in the contact zones where the glass pieces scrape against each other. • Investigate - with aim to characterize - the material modellingof the interlayer at large strains, for quasi-static loadingconditions and on a temperature range from ~-15°C to ~+65°C • Investigate - with aim to characterize - the adhesion propertiesand behaviour, in particular in SGP-laminates, for similarconditions• Delincé D., et al. Proceedings of Challenging Glass Conference, Delft, 2008, pp. 459-467. • Depauw J., Master thesis, Ghent University, Ghent, 2006.• Sackmann V., Meissner M. Proc. International Symposium on the Application of Architectural Glass, Munich, 2006. • Kott A., Vogel T., Proc. Glass Processing Days, Tampere, Finland, 2003, pp. 403-407.Observations for the tested four-points configurations :• SGP-laminates show some residual resistance in post-breakage stage, contrary to PVB-laminates, which fail under the dead load of the plate• For SGP-laminates a “yield-section” (similar to a plastic hinge) often forms naturally round a cracked zone in the width of the plate• The failure of the SGP-laminates is often due to the tearing up (breakage) of the interlayer in the “yield-section”, but the splitting up of the glass at the upper face (in compression) alsoplays a significant rol in the failure processMain outcomes :• There is a fundamental difference in mechanical behaviour of SGP and PVB at room temperature, but considering the broader temperature range that can occur in practical cases (from below the glass transition temperature of PVB to above the glass transition temperature of SGP),  they show a similar behaviour typical for polymers.  Consequently, we expect to apply similar methodology for the material modelling of the interlayer.• There is a clear interaction and interdependencebetween the 3 identified mechanisms ruling the failure : the safety of the failure of laminated glass in static conditions is dependent of the stiffness of the interlayer AND of its adhesion level to glass, and also depends on the breakage pattern of the glass.• No general rules can yet be extrapolated to assess the safety (post-breakage behaviour) of laminated glass regarding to the choice of the interlayer material !

https://biblio.ugent.be/publication/441763/file/450002

Failure behaviour of glass laminates with a "stiff" interlayer at room temperature

Abstract

Similar works

Full text

Available Versions

Ghent University Academic Bibliography

Archivsystem Ask23

Ghent University Academic Bibliography