Bsi bs en 02377 1989 (2000)

www bzfxw com BRITISH STANDARD AEROSPACE SERIES BS EN 2377 1989 Glass fibre reinforced plastics — Test method — Determination of apparent interlaminar shear strength This European Standard EN 2377 has[.]

BRITISH STANDARD AEROSPACE SERIES BS EN

2377:1989

Glass fibre reinforced

plastics — Test

method —

Determination of

apparent interlaminar

shear strength

This European Standard EN 2377 has the status of a

British Standard

UDC 678.067.5-41:620.176:629.7

This British Standard, having

been prepared under the

direction of the Aerospace

Standards Policy Committee,

was published under the

authority of the Board of

BSI and comes into effect on

30 November 1989

© BSI 01-2000

The following BSI references

relate to the work on this

standard:

Committee reference ACE/64

Draft for comment 88/70403 DC

ISBN 0 580 17743 2

Cooperating organizations

The European Committee for Standardization, under whose supervision this European Standard was prepared, comprises the national standards

organizations of the following Western European countries

Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y

France Association française de normalisation Germany Deutsches Institut für Normung e.V

Greece Hellenic Organization for Standardization Iceland Icelandic Council for Standardization Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxemburg Inspection des travails et des mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Português da Qualidade Spain Instituto Español de Normalización Sweden Standardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom British Standards Institution

Amendments issued since publication

Amd No Date of issue Comments

BS EN 2377:1989

Contents

Page

ii © BSI 01-2000

National foreword

This British Standard has been prepared under the direction of the Aerospace Standards Policy Committee and is the English language version of EN 2377

“Aerospace series Glass fibre reinforced plastics Test method Determination of

apparent interlaminar shear strength”, published by the European Committee for

Standardization (CEN) EN 2377 was produced as a result of international discussion in which the UK took an active part

A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application

Compliance with a British Standard does not of itself confer immunity from legal obligations.

Summary of pages

This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 6, an inside back cover and a back cover

This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover

EUROPEAN STANDARD

NORME EUROPÉENNE

EUROPÄISCHE NORM

EN 2377

January 1989

UDC: 678.067.5-41:620.176:629.7

Key words: Aircraft industry, glass reinforced plastics, plates, test method, shear stress

English version Aerospace series Glass fibre reinforced plastics

Test method Determination of apparent interlaminar shear strength

Série aérospatiale

Plastiques renforcés de fibres de verre

Méthode d’essai

Détermination des propriétés

en cisaillement apparent interlaminaire

Luft- und Raumfahrt Glasfaserverstärkte Kunststoffe Prüfverfahren zur

Bestimmung der scheinbaren interlaminaren Scherfestigkeit

This European Standard was accepted by CEN on 1988-03-17 CEN members

are bound to comply with the requirements of CEN Internal Regulations which

stipulate the conditions for giving this European Standard the status of a

national standard without any alteration

Up-to-date lists and bibliographical references concerning such national

standards may be obtained on application to the Central Secretariat or to any

CEN member

This European Standard exists 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 CEN

Central Secretariat has the same status as the official versions

CEN members are the national standards organizations of Austria, Belgium,

Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,

Luxemburg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and

United Kingdom

CEN

European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung

Central Secretariat: rue de Stassart 36, B-1050 Brussels

© CEN 1989 Copyright reserved to all CEN members

Ref No EN 2377:1989 E

© BSI 01-2000 2

Brief history

This draft European Standard has been prepared by

the European Association of Aerospace

Manufacturers (AECMA)

After enquiries and votes carried out in accordance

with the rules of this Association, this draft has

successively received the approval of the National

Associations and the Official Services of the member

countries of AECMA, prior to its presentation to

CEN

In accordance with the Common CEN/CENELEC

Rules, the following countries are bound to

implement this European Standard: Austria,

Belgium, Denmark, Finland, France, Germany,

Greece, Iceland, Ireland, Italy, Luxemburg,

Netherlands, Norway, Portugal, Spain, Sweden,

Switzerland and United Kingdom

Contents

Page

1 Scope and field of application 3

10 Calculation and expression of results 5

Annex A Determination of the estimated

Figure 3.a — Shear modes of failure 4 Figure 3.b — Non-shear modes of failure 5

EN 2377:1989

1 Scope and field of application

This standard defines a method for the

determination of the apparent interlaminar shear

strength by delamination of textile glass fibre

reinforced plastics produced in sheet form for

aerospace use

2 References

EN 62, Glass reinforced plastics — Standard

atmospheres for conditioning and testing

EN 2374, Aerospace series — Glass fibre reinforced

mouldings and sandwich composites — Production

of test panels

3 Definition

The apparent interlaminar shear strength is the

maximum interlaminar shear stress at the moment

of first failure It is expressed in MPa

4 Principle of the method

For the determination of the resistance in

interlaminar shear parallel to the layers of

reinforcement, a specimen of rectangular cross

section is tested in flexion The specimen resting on

two supports and the force applied by means of a

loading nose midway between the supports

5 Test specimens

The test specimens are prepared according

to EN 2374

5.1 Dimensions 5.1.1 Standard specimens

5.1.2 Alternative specimens

When it is not possible or desirable to use the standard specimens, the following rules shall be observed:

a) The length and the thickness of the test specimen shall be in the same ratio as in the standard specimen:

1 = 6,7 h ± 0,5 mm b) The width and the thickness of the test specimen shall be in the same ratio as in the standard specimen:

b = 3,3 h ± 0,2 mm

WARNING: If the thickness of the test specimen is greater than 3 mm excessive compressive stresses may occur under the loading nose

5.2 Position of specimens

See Figure 1

5.3 Number of test specimens 5.3.1 The number of test specimens shall be a minimum of 5 from each direction

5.3.2 When the material shows a significant difference in shear properties in two principal directions, it is to be tested in these two directions (see Figure 1, specimen A and B)

When the fibres are oriented unidirectionally, the test shall be carried out in that direction only

Length 1 : (20 ± 0,5) mm Width b : (10 ± 0,2) mm Thickness h : (3 ± 0,2) mm

Figure 1

4 © BSI 01-2000

6 Apparatus

Calibrated standard testing machine, which can be

operated at a constant rate of the loading nose and

in which the accuracy of measurement shall be

within ± 1 %

The loading nose and supports shall be made from

steel having a tensile strength U 1 000 MPa

The span shall be adjustable

7 Conditioning

The standard atmosphere shall be in accordance

with EN 62

The test specimens shall be conditioned

at (23 ± 2) °C and (50 ± 5) % relative humidity

during at least 16 h

8 Procedure

Unless otherwise specified, carry out the test

at (23 ± 2) °C and (50 ± 5) % relative humidity

Measure the dimensions of b and h to the nearest 0,05 mm, respectively and adjust the span

to lV= 5 h ± 0,1 mm

Load the specimen without bumping with a rate of the loading nose of V = (1 ± 0,1) mm/min

(see Figure 2)

The load shall be taken as a function of time or displacement of the loading nose

9 Test results

9.1 If the specimens fail in horizontal shear approximately at the neutral fibre axis (see Figure 3.a), the true interlaminar shear stress shall be calculated in accordance with the formula

in clause 10.

9.2 If test specimens fail in flexural i.e tension

or compression failure of the outer surface (see Figure 3.b), the results calculated by the

formula in clause 10 are not true shear stresses.

These results shall only be used for a comparison of test series of a same material (i.e batch control)

Figure 2 — Testing device

NOTE In the case of translucent materials an off-white colour becomes evident.

Figure 3.a — Shear modes of failure

EN 2377:1989

10 Calculation and expression of

results

The apparent shear stress shall be calculated as

follows:

where:

11 Test report

The test report shall include the following

informations:

11.1 Number of this standard, brand, identification

mark, origin, date of receipt and further data of the

tested material

11.2 Data about the preparation of the test

specimens

11.3 Measured dimensions of the test specimens and of the span

11.4 Actual radii of the loading nose and supports

11.5 A graph representing the load measured as a function of time or displacement

11.6 When test specimens have been broken in shear the single values, the arithmetic mean and the standard deviation (see Annex A) shall be recorded

11.7 When test specimens have not been broken in shear a full description of type of failure shall be given with the note, that the calculated stresses are not true shear stresses

The single values, the arithmetic mean and the standard deviation (see Annex A) shall be recorded

11.8 Test conditions i.e temperature and relative humidity if deviating from this standard

11.9 Observations on any circumstances liable to influence the results

Figure 3.b — Non-shear modes of failure

E = The apparent shear stress in MPa

F = Maximum force at the moment of the

first failure, in N

b = Width of specimen in mm

h = Thickness of specimen in mm

Ùô 3

4

- F

b h

-=

6 © BSI 01-2000

Annex A Determination of the

estimated value of standard deviation

The estimated value of standard deviation S is

calculated from the formula:

where:

NOTE With sufficient exactness for most purposes the value of

the standard deviation of a series of 5 results can be calculated as

follows:

Standard deviation S = 0,430 R

where:

xi observations

arithmetical mean of the values xi

n number of observations

R The difference in value between the highest and lowest

result in the series of 5 tests.

x

BS EN 2377:1989

© BSI 01-2000

National appendix A

The United Kingdom participation in the preparation of this European Standard was entrusted by the Aerospace Standards Policy Committee (ACE/-) to Technical Committee ACE/64, upon which the following bodies were represented:

British Plastics Federation

Ministry of Defence

Society of British Aerospace Companies Limited

National appendix B

The British Standards corresponding to the European Standards referred to in the text are identical in

number and title with those given in clause 2 with the exception of EN 62, for which the corresponding

British Standard is BS 2782 “Methods of testing plastics” Part 10: Method 1004 “Standard atmospheres for

conditioning and testing” (content identical).

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