Rubber- or plastics-coated fabrics - Mechanical test methods under biaxial stress states - Part 2: Determination of the pattern compensation values

This document describes methods for the determination of compensation values for orthotropic coated fabrics (different properties along ideally perpendicular directions, such as the weft and warp yarns for woven based coated fabrics, or along the courses and wales of knitted based coated fabrics) for determining cutting patterns.
NOTE The final interpretation and the determination of the compensation values remains the responsibility of the project engineer.
Annex C describes a method to determine comparable measures of extensibility along ideally perpendicular directions of coated fabrics. The comparable measures of extensibility can be used by design engineers to assess the extensibility of a coated fabric by comparison with other coated fabrics. In this way, they can help to interpret results of compensation tests. Moreover, they can be used by material suppliers to measure the consistency of extensibility along perpendicular directions of a coated fabric from batch to batch.

Mit Kautschuk oder Kunststoff beschichtete Textilien — Mechanische Prüfverfahren unter biaxialen Spannungszuständen — Teil 2: Bestimmung der Kompensationswerte

Dieses Dokument beschreibt Verfahren zur Bestimmung der Kompensationswerte für orthotrope beschich-tete Textilien (unterschiedliche Eigenschaften in Bezug auf idealerweise senkrechte Richtungen wie Schuss und Kette bei gewebten beschichteten Textilien oder entlang der Produktionsrichtung und senkrecht dazu bei beschichteten Maschenwaren) zwecks Bestimmung der Schnittmuster.
ANMERKUNG Die endgültige Interpretation und die Bestimmung der Kompensationswerte verbleibt in der Verant-wortung des Projektingenieurs.
Anhang C beschreibt ein Verfahren zur Bestimmung von Vergleichsmaßen der Dehnfähigkeit in Bezug auf idealerweise senkrechte Richtungen bei beschichteten Textilien. Die Vergleichsmaße der Dehnfähigkeit können von Tragwerksplanern zur Bewertung der Dehnfähigkeit eines beschichteten Textils durch Vergleich mit anderen beschichteten Textilien verwendet werden. Auf diese Weise können sie bei der Interpretation der Ergebnisse der Kompensationsversuche helfen. Darüber hinaus können sie von Werkstofflieferanten zur chargenübergreifenden Messung der Konsistenz der Dehnfähigkeit in Bezug auf senkrechte Richtungen eines beschichteten Textils verwendet werden.

Supports textiles revêtus de caoutchouc ou de plastique - Méthodes d’essais mécaniques sous contraintes biaxiales - Partie 2: Détermination des valeurs de compensation du patronnage

Le présent document décrit les méthodes de détermination des valeurs de compensation pour les supports textiles revêtus orthotropes (différentes propriétés suivant des directions idéalement perpendiculaires, comme les fils de trame et de chaîne pour les supports textiles revêtus tissés, ou suivant les rangées et colonnes de mailles des supports textiles revêtus tricotés) afin de déterminer les patrons de coupe.
NOTE L’interprétation finale et la détermination des valeurs de compensation restent de la responsabilité de l’ingénieur du projet.
L’Annexe C décrit une méthode permettant de déterminer des mesures d’extensibilité comparables suivant des directions idéalement perpendiculaires des supports textiles revêtus. Les mesures d’extensibilité comparables peuvent être utilisées par les ingénieurs de conception pour évaluer l’extensibilité d’un support textile revêtu par comparaison avec d’autres supports textiles revêtus. Elles peuvent ainsi faciliter l’interprétation des résultats des essais de compensation. En outre, elles peuvent être utilisées par les fournisseurs de matériaux pour mesurer la constance de l’extensibilité dans les directions perpendiculaires d’un support textile revêtu entre les lots.

Gumirane ali plastificirane tekstilije - Mehanske preskusne metode v dvoosnih napetostnih stanjih - 2. del: Določanje vrednosti kompenzacije vzorca

General Information

Status
Published
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
28-Jul-2021
Completion Date
28-Jul-2021

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SLOVENSKI STANDARD
oSIST prEN 17117-2:2021
01-januar-2021
Gumirane ali plastificirane tekstilije - Mehanske preskusne metode v dvoosnih
napetostnih stanjih - 2. del: Določanje vrednosti kompenzacije vzorca

Rubber- or plastics-coated fabrics - Mechanical test methods under biaxial stress states -

Part 2: Determination of the pattern compensation values

Mit Kautschuk oder Kunststoff beschichtete Textilien - Mechanische Prüfverfahren unter

biaxialer Spannung - Teil 2: Bestimmung der Kompensationswerte
Supports textiles revêtus de caoutchouc - Méthodes d'essais mécaniques sous
contraintes biaxiales - Partie 2 : Détermination des valeurs de compensation des
modèles
Ta slovenski standard je istoveten z: prEN 17117-2
ICS:
59.080.40 Površinsko prevlečene Coated fabrics
tekstilije
oSIST prEN 17117-2:2021 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 17117-2:2021
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oSIST prEN 17117-2:2021
DRAFT
EUROPEAN STANDARD
prEN 17117-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2021
ICS 59.080.40
English Version
Rubber- or plastics-coated fabrics - Mechanical test
methods under biaxial stress states - Part 2: Determination
of the pattern compensation values

Supports textiles revêtus de caoutchouc - Méthodes Mit Kautschuk oder Kunststoff beschichtete Textilien -

d'essais mécaniques sous contraintes biaxiales - Partie Mechanische Prüfverfahren unter biaxialer Spannung -

2 : Détermination des valeurs de compensation des Teil 2: Bestimmung der Kompensationswerte

modèles

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 248.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations

which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC

Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17117-2:2021 E

worldwide for CEN national Members.
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oSIST prEN 17117-2:2021
prEN 17117-2:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

Introduction .................................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 5

2 Normative references .................................................................................................................................... 5

3 Terms and definitions ................................................................................................................................... 5

4 Principle ............................................................................................................................................................. 8

5 Apparatus ........................................................................................................................................................... 8

5.1 Biaxial test equipment .................................................................................................................................. 8

5.2 Measurement of load ..................................................................................................................................... 8

5.3 Measurement of strain .................................................................................................................................. 8

6 Atmosphere for conditioning and testing .............................................................................................. 8

7 Sampling and preparation of test specimens ........................................................................................ 8

7.1 Bulk sample (number of pieces from a shipment or lot) .................................................................. 8

7.2 Number of laboratory samples .................................................................................................................. 8

7.3 Specimen geometry and preparation ...................................................................................................... 8

8 Test procedure ................................................................................................................................................. 8

8.1 Mounting of the specimen ............................................................................................................................ 9

8.2 Loading and selection of strain values .................................................................................................... 9

8.3 Testing .............................................................................................................................................................. 12

8.4 Recording ........................................................................................................................................................ 12

9 Representation of test results and calculation of compensation values .................................. 12

9.1 Representation.............................................................................................................................................. 12

9.2 Determination of compensation values ............................................................................................... 13

9.3 Decompensation ........................................................................................................................................... 13

9.4 Comparable measures of extensibility ................................................................................................. 13

10 Test report ...................................................................................................................................................... 13

Annex A (informative) Load profiles and selected strain values (examples) ....................................... 14

A.1 Generality ........................................................................................................................................................ 14

A.2 Load profiles – example I ........................................................................................................................... 14

A.3 Load profiles – example II ......................................................................................................................... 15

A.4 Load profiles – example III........................................................................................................................ 18

Annex B (informative) Example evaluation of project specific compensation values ....................... 19

Annex C (normative) Load profile for comparative extensibility measures of coated fabrics ....... 22

Bibliography ................................................................................................................................................................. 23

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prEN 17117-2:2020 (E)
European foreword

This document (prEN 17117-2:2020) has been prepared by Technical Committee CEN/TC 248 “Textiles

and textile products”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.

EN 17117 consists of the following parts, under the general title Rubber- or plastics-coated fabrics —

Mechanical test methods under biaxial stress states:
— Part 1: Tensile stiffness properties
— Part 2: Determination of the pattern compensation values

An additional part related to shear stiffness properties will be proposed after the publication of the

previous parts.
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Introduction

Compensation is the process of reducing the size of cutting patterns with the objective to introduce and

maintain the desired range of prestress specified in the structural design using coated fabrics such as

architectural tensioned envelopes. Elastic strain correspondent to the prestress and irreversible strain

of the coated fabrics induced by tensioning during installation and potential load incidents over the

lifetime of an architectural tensioned envelope, should be compensated to achieve the objective. Different

compensation values may be applied to different parts of the same architectural tensioned envelope.

Decompensation may also be applied if required.
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1 Scope

This document describes methods for the determination of compensation values for orthotropic coated

fabrics (different properties along ideally perpendicular directions, such as the weft and warp yarns for

woven based coated fabrics, or along the courses and wales of knitted based coated fabrics) for

determining cutting patterns.

NOTE The final interpretation and the determination of the compensation values remains the responsibility of

the project engineer.

Annex C describes a method to determine comparable measures of extensibility along ideally

perpendicular directions of coated fabrics. The comparable measures of extensibility can be used by

design engineers to assess the extensibility of a coated fabric by comparison with other coated fabrics. In

this way, they can help to interpret results of compensation tests. Moreover, they can be used by material

suppliers to measure the consistency of extensibility along perpendicular directions of a coated fabric

from batch to batch.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

EN 17117-1, Rubber or plastics-coated fabrics - Mechanical test methods under biaxial stress states - Part

1: Tensile stiffness properties
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
biaxial
measurement or application along two axes simultaneously
[SOURCE: EN 17117-1:2018, 3.1]
3.2
compensation

reduction in size of a cutting pattern, so that during installation the panel elongates to achieve an initial

nominal prestress
3.3
compensation value

amount by which the dimensions of the pattern geometry is reduced by compensation

Note 1 to entry: The compensation value is expressed as a percentage of length in the direction to be

compensated.
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3.4
cutting pattern

two-dimensional geometry developed from a pattern to be cut out of the individual piece of a coated

fabric
3.5
decompensation
partial or complete reduction of compensation

Note 1 to entry: Decompensation may be applied to ease the installation process, typically in the vicinity of

boundaries.

Note 2 to entry: Typical application of compensation and decompensation to a piece of a coated fabric is depicted

in Figure 1.
Key
1 final geometry when stressed with nominal prestress
2 geometry compensated, unstressed
3 geometry decompensated, unstressed
4 half of the pattern compensation measure in warp (wale, respectively)
5 half of the pattern compensation measure in fill (course, respectively)

Figure 1 — Typical application of compensation and decompensation to a piece of a coated

fabric
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3.7
overstressing
stressing beyond the nominal prestress level during the installation of a panel
3.8
panel

final three-dimensional assembly of pieces of a coated fabric, cut according to the cutting pattern, ready

to be installed on site

Note 1 to entry: An architectural tensioned envelope may be made of more than one panel.

3.9
piece of a coated fabric
two-dimensional piece cut from a roll of coated fabric
3.10
nominal prestress

input data of prestress, prescribed during the form finding and structural analysis, and part of the

structural design
3.11
pattern

seam layout based subdivision of a three-dimensional surface into a piece of a coated fabric

3.12
seam layout

definition of location and direction of seams over the surface of an architectural tensioned envelope

3.13
W1,5

load applied in the warp (respectively wale) direction with a magnitude of 1,5 % of the ultimate tensile

strength (UTS) in the warp (respectively wale) direction
3.14
F1,5

load applied in the fill (respectively course) direction with a magnitude of 1,5 % of the ultimate tensile

strength (UTS) in the fill (respectively course) direction
3.15
W10

load applied in the warp (respectively wale) direction with a magnitude of 10 % of the ultimate tensile

strength (UTS) in the warp (respectively wale) direction
3.16
F10

load applied in the fill (respectively course) direction with a magnitude of 10 % of the ultimate tensile

strength (UTS) in the fill (respectively course) direction
3.17
MIN1,5
minimum of W1,5 and F1,5
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3.18
MIN10
minimum of W10 and F10
4 Principle

Strains measured during the biaxial loading in warp and fill (respectively wale and course) directions of

the coated fabric are used to derive the compensation values.
5 Apparatus
5.1 Biaxial test equipment
Shall be according to EN 17117-1:2018, 5.1.
5.2 Measurement of load
Shall be according to EN 17117-1:2018, 5.2.
5.3 Measurement of strain
Shall be according to EN 17117-1:2018, 5.3.
6 Sampling and preparation of test specimens
6.1 Bulk sample (number of pieces from a shipment or lot)
Shall be according to EN 17117-1:2018, 6.1.
6.2 Number of laboratory samples
Shall be according to EN 17117-1:2018, 6.2.
6.3 Specimen geometry and preparation
6.3.1 General
Shall be according to EN 17117-1:2018, 6.3.1.
6.3.2 Contact strain measurement
Shall be according to EN 17117-1:2018, 6.3.2.
6.3.3 Non-contact strain measurement
Shall be according to EN 17117-1:2018, 6.3.3.
7 Atmosphere for conditioning and testing
Shall be according to EN 17117-1:2018, Clause 7.
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8 Test procedure
8.1 Mounting of the specimen
Shall be according to EN 17117-1:2018, 8.1.
8.2 Loading and selection of strain values

In order to derive project specific compensation values from selected strain values, project specific load

profiles should be individually specified. The specimen is loaded by forces in the warp and fill

(respectively wale and course) directions with prescribed magnitudes and ratios.
Example of project specific load profiles are illustrated in Annex B.
Load ratios are used to define a load cycle with start, middle and end values.
The specification of the load profile should include consideration of:
— design nominal prestress;

— design biaxial stresses arising from characteristic external loads, e.g. wind, snow. Design biaxial

stresses should be representative (e.g. an average value) for the area over which the compensation

value is to be applied;
— type of external loads, e.g. wind, snow;
— design biaxial stress ratios;
— duration of design biaxial stresses;
— probability of design biaxial stresses;
— spatial representation of design biaxial stresses;
— area over which the compensation value is to be applied;
— overstressing anticipated during installation;

— installation process, e.g. order of prestressing of the yarn directions during installation.

Typically, two dominant load cases can be derived from the structural analysis: one with predominant

warp stress and one with predominant fill stress. The respective stresses in warp and fill direction

together with the corresponding stresses in the perpendicular direction should be used to specify the

load profile. The load profile should consist of the steps given in Table 1. In some cases, e.g. pneumatic

structures or plane frames, only one load case may exist. In these cases, steps 4 and 5 can be neglected.

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Table 1 — Steps for the individual specification of the load profile
Step Simulation of Remarks
Prestress/installation Nominal prestress held constant over a
specified period of time. Overstressing may be
considered. Prestress may be applied in
several cycles prior to holding it constant.
Load case with predominant warp stress Long-term nature of a load case may be
2 together with corresponding fill stress, considered by holding maximum stress
repeated several times constant over a specified period of time
3 Period of nominal prestress held constant -
Load case with predominant fill stress Long-term nature of a load case may be
4 together with corresponding warp stress, considered by holding maximum stress
repeated several times constant over a specified period of time
5 Period of nominal prestress held constant -
6 Repetition of steps 1 to 5 may be considered -

Example loading options in step 1 “Prestress/installation” are illustrated in Figure 2: Loading and

nominal prestress held constant (a), simulation of overstressing prior to prestress held constant (b),

prestress cycling prior to prestress held constant (c).

Example loading options in step 2 “predominant warp loading” are illustrated in Figure 3: short-term

load cycle (a), long-term load cycle (b). For step 4 “predominant fill loading” the options for step 2

“predominant warp loading” can be applied analogous.
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a b c
Key
1 time axis
2 stress axis
3 warp
4 fill
5 time at the end of step 1
Figure 2 — Example loading options for step 1 of the loa
...

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