SIST EN 1999-1-3:2007/A1:2012
(Amendment)Eurocode 9: Design of aluminium structures - Part 1-3: Structures susceptible to fatigue
Eurocode 9: Design of aluminium structures - Part 1-3: Structures susceptible to fatigue
(1) EN 1999-1-3 gives the basis for the design of aluminium alloy structures with respect to the limit state of fracture induced by fatigue.
(2) EN 1999-1-3 gives rules for:
- Safe life design;
- damage tolerant design;
- design assisted by testing.
(3) EN 1999-1-3 is intended to be used in conjunction with EN 1090-3 "Technical requirements for the execution of aluminium structures" which contains the requirements necessary for the design assumptions to be met during execution of components and structures.
(4) EN 1999-1-3 does not cover pressurised containment vessels or pipe-work.
Eurocode 9: Bemessung und Konstruktion von Aluminiumtragwerken - Teil 1-3: Ermüdungsbeanspruchte Tragwerke
Eurocode 9: Calcul des structures en aluminium - Partie 1-3: Structures sensibles à la fatigue
Evrokod 9: Projektiranje konstrukcij iz aluminijevih zlitin - 1-3. del: Konstrukcije, občutljive na utrujanje
1.1.1 Področje uporabe standarda EN 1999
(1) P EN 1999 se uporablja za projektiranje stavb ter gradbenih inženirskih in kostrukcijskih objektov iz aluminija. Upošteva načela in zahteve glede varnosti in uporabnosti konstrukcij ter podlago za njihovo projektiranje in preverjanje, ki so podane v standardu EN 1990 – Osnove projektiranja konstrukcij.
(2) EN 1999 se nanaša le na zahteve za odpornost, uporabnost, trajnost in požarno odpornost aluminijastih konstrukcij. Ostale zahteve, na primer glede toplotne in zvočne izolativnosti, niso obravnavane.
(3) EN 1999 je namenjen za uporabo v povezavi z naslednjimi standardi:
– EN 1990 Osnove projektiranja konstrukcij
– EN 1991 Vplivi na konstrukcije
– Evropski standardi za gradbene izdelke, ki se nanašajo na aluminijaste konstrukcije
– EN 1090-1: Izvedba jeklenih konstrukcij in aluminijastih konstrukcij - 1. del: Zahteve za ugotavljanje skladnosti sestavnih delov konstrukcij
– EN 1090-3: Izvedba jeklenih in aluminijastih konstrukcij - 3. del: Tehnične zahteve za aluminijaste konstrukcije
(4) EN 1999 je razdeljen na pet delov:
EN 1999-1-1 Projektiranje konstrukcij iz aluminijevih zlitin: Splošna pravila za konstrukcije
EN 1999-1-2 Projektiranje konstrukcij iz aluminijevih zlitin: Projektiranje požarnovarnih konstrukcij
EN 1999-1-3 Projektiranje konstrukcij iz aluminijevih zlitin: Konstrukcije, občutljive na utrujanje
EN 1999-1-4 Projektiranje konstrukcij iz aluminijevih zlitin: Hladno oblikovane konstrukcijske pločevine
EN 1999-1-5 Projektiranje konstrukcij iz aluminijevih zlitin: Lupinaste konstrukcije
1.1.2 Področje uporabe standarda EN 1999-1-3
(1) EN 1999-1-3 podaja podlago za projektiranje konstrukcij iz aluminijevih zlitin v zvezi z mejnim stanjem preloma zaradi utrujanja.
(2) EN 1999-1-3 podaja pravila za:
– projektiranje po kriteriju varne življenjske dobe ;
– projektiranje po kriteriju tolerance škode;
– projektiranje s pomočjo preskušanja.
(3) EN 1999-1-3 je namenjen za uporabo v povezavi s standardom EN 1090-3 – Tehnične zahteve za aluminijaste konstrukcije – ki vsebuje zahteve, potrebne za izpolnjevanje projektnih predpostavk med izvedbo sestavnih delov in konstrukcij.
(4) EN 1999-1-3 ne obravnava tlačnih posod ali cevi.
(5) EN 1999-1-3 obravnava:
Oddelek 1: Splošno
Oddelek 2: Osnove projektiranja
Oddelek 3: Materiali, sestavni izdelki in spojne naprave
Oddelek 4: Trajnost
Oddelek 5: Analiza konstrukcije
Oddelek 6: Končno mejno stanje utrujanja
Dodatek A: Podlaga za izračun odpornosti proti utrujanju [normativni]
Dodatek B: Smernice za ocenjevanje z mehaniko loma [informativni]
Dodatek C: Preskušanje glede projektiranja za utrujanje [informativni]
Dodatek D: Analiza obremenitve [informativni]
Dodatek E: Lepljeni spoji [informativni]
Dodatek F: Razpon malocikličnega utrujanja [informativni]
Dodatek G: Vpliv razmerja R [informativni]
Dodatek H: Izboljšanje trajne nihajne trdnosti zvarov [informativni]
Dodatek I: Ulitki [informativni]
Dodatek J: Preglednice s podrobnimi kategorijami [informativni]
Dodatek K: Podrobna metoda za ugotavljanje vročih točk [informativni]
Literatura
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 1999-1-3:2007/A1:2012
01-februar-2012
(YURNRG3URMHNWLUDQMHNRQVWUXNFLML]DOXPLQLMHYLK]OLWLQGHO.RQVWUXNFLMH
REþXWOMLYHQDXWUXMDQMH
Eurocode 9: Design of aluminium structures - Part 1-3: Structures susceptible to fatigue
Eurocode 9: Bemessung und Konstruktion von Aluminiumtragwerken - Teil 1-3:
Ermüdungsbeanspruchte Tragwerke
Eurocode 9: Calcul des structures en aluminium - Partie 1-3: Structures sensibles à la
fatigue
Ta slovenski standard je istoveten z: EN 1999-1-3:2007/A1:2011
ICS:
91.010.30 7HKQLþQLYLGLNL Technical aspects
91.080.10 Kovinske konstrukcije Metal structures
SIST EN 1999-1-3:2007/A1:2012 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 1999-1-3:2007/A1:2012
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SIST EN 1999-1-3:2007/A1:2012
EUROPEAN STANDARD
EN 1999-1-3:2007/A1
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2011
ICS 91.010.30; 91.080.10
English Version
Eurocode 9: Design of aluminium structures - Part 1-3:
Structures susceptible to fatigue
Eurocode 9: Calcul des structures en aluminium - Partie 1- Eurocode 9: Bemessung und Konstruktion von
3: Structures sensibles à la fatigue Aluminiumtragwerken - Teil 1-3: Ermüdungsbeanspruchte
Tragwerke
This amendment A1 modifies the European Standard EN 1999-1-3:2007; it was approved by CEN on 26 May 2011.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of this
amendment into the relevant national standard without any alteration. Up-to-date lists and bibliographical references concerning such
national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This amendment 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 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1999-1-3:2007/A1:2011: E
worldwide for CEN national Members.
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SIST EN 1999-1-3:2007/A1:2012
EN 1999-1-3:2007/A1:2011 (E)
Contents
Foreword . 3
1 Modification to Foreword . 4
2 Modification to 1.5.2.34 . 4
3 Modification to 1.6 . 4
4 Modification to Clause 2 . 6
5 Modification to 5.8.1 (2) . 10
6 Modification to 5.8.2 (1) . 10
7 Modifications to 6.2.1 (2) . 10
8 Modification to A.2.1 (5) . 11
9 Modification to A.3.1 . 12
10 Modifications to A.3.2 . 12
11 Addition of Annex L . 13
L.1 Safe life method . 13
L.2 Damage tolerant design method . 13
L.3 Start of inspection and inspection intervals . 15
L.4 Partial factors γγγγ and the values of D . 16
Mf Lim
L.5 Parameters for execution . 17
L.5.1 Service category . 17
L.5.2 Calculation of utilisation grade . 18
2
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SIST EN 1999-1-3:2007/A1:2012
EN 1999-1-3:2007/A1:2011 (E)
Foreword
This document (EN 1999-1-3:2007/A1:2011) has been prepared by Technical Committee CEN/TC 250
“Structural Eurocodes”, the secretariat of which is held by BSI.
This Amendment to the European Standard EN 1999-1-3:2007 shall be given the status of a national
standard, either by publication of an identical text or by endorsement, at the latest by August 2012,
and conflicting national standards shall be withdrawn at the latest by August 2012.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such
patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: 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,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.
3
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SIST EN 1999-1-3:2007/A1:2012
EN 1999-1-3:2007/A1:2011 (E)
1 Modification to Foreword
At the end of the Foreword, in the list of clauses where national choice is allowed,
replace “2.1(1)” with “2.1.1(1)”, “2.2.1(3)” with “2.2.1(4)” and “2.3.1(3)” with “2.3.1(2)” and
delete “6.2.4(1)” and “A.3.1(1)”
2 Modification to 1.5.2.34
Replace 1.5.2.34 with the following: "
1.5.2.34
safe life
period of time for which a structure is estimated to perform safely with an acceptable probability that
failure by fatigue cracking will not occur, when using the safe life design method".
3 Modification to 1.6
For the definition of symbol m, delete “constant”
Replace
“N endurance under stress range ∆σ”
i i
with
“N predicted number of cycles to failure of a stress range ∆σ”
i i
and replace
“T inspection interval”
i
with
“T inspection interval
i
T recommended time after completed erection for the start of fatigue inspection, where the
F
fatigue inspection comprises the inspection of areas with high probability for cracks
T recommended time after completed erection for start of general inspection, where the
G
general inspection comprises checking that the structure is as it was when it was completed
and approved, i.e. that no deterioration has taken place, such as deterioration caused by
adding detrimental holes or welds for additional elements, damage due to vandalism or
accidents, unexpected corrosion etc.”
and replace
"γ partial factor for fatigue load intensity
Ff
γ partial factor for fatigue strength
Mf
∆σ nominal stress range (normal stress)
∆τ effective shear stress range
6
∆σ reference fatigue strength at 2x10 cycles (normal stress)
C
4
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SIST EN 1999-1-3:2007/A1:2012
EN 1999-1-3:2007/A1:2011 (E)
∆σ constant amplitude fatigue limit
D
∆σ equivalent constant amplitude stress range related to N
E max
6
∆σ equivalent constant amplitude stress range related to 2x10 cycles
E,2
∆σ cut-off limit
L
∆σ fatigue strength (normal stress)
R
σ , σ maximum and minimum values of the fluctuating stresses in a stress cycle
max min
σ mean stress."
m
with
"λ damage equivalent factor depending on the load situation and the structural
i
characteristics as well as other factors
γ partial factor for fatigue load intensity
Ff
γ partial factor for fatigue strength
Mf
∆σ nominal stress range (normal stress)
NOTE ∆σ refers either to action effects or to fatigue strength depending on context.
∆τ effective shear stress range
∆σ constant stress range for the principal stresses in the construction detail for n cycles
i i
6
∆σ reference fatigue strength at 2 × 10 cycles (normal stress)
C
∆σ constant amplitude fatigue limit
D
∆σ nominal stress range from fatigue actions
E
∆σ equivalent constant amplitude stress range related to N
E,Ne max
6
∆σ equivalent constant amplitude stress range related to 2 × 10 cycles
E,2e
∆σ cut-off limit
L
∆σ fatigue strength (normal stress)
R
recommended maximum time interval for general inspection
∆T
F
∆T recommended maximum time interval for fatigue inspection
G
σ , σ maximum and minimum values of the fluctuating stresses in a stress cycle
max min
σ mean stress."
m
and add
"D design fatigue damage value calculated for the full design life".
L.d
5
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SIST EN 1999-1-3:2007/A1:2012
EN 1999-1-3:2007/A1:2011 (E)
4 Modification to Clause 2
Replace Clause 2 with the following: "
2 Basis of design
2.1 General
2.1.1 Basic requirements
(1) P The aim of designing a structure against the limit state of fatigue is to ensure, with an acceptable
level of probability, that its performance is satisfactory during its entire design life, such that the
structure shall not fail by fatigue nor shall it be likely to require undue repair of damage caused by
fatigue during the design life. The design of aluminium structures against the limit state of fatigue may
be based on one of following methods:
a) safe life design (SLD) (see 2.2.1);
b) damage tolerant design (DTD) (see 2.2.2).
Either of methods a) and b) may be supplemented or replaced by design assisted by testing (see
2.2.3).
NOTE The national annex may specify conditions for the application for the above methods of design.
(2) The method for design against fatigue should be selected taking the use of the structure into
account, considering the consequence class fixed for the components of the structure. In particular the
accessibility for inspection of components and details where fatigue cracks are likely to occur should
be considered.
(3) Fatigue assessment of components and structures should be considered in cases where the loads
are frequently changing, particularly if reversing. Common situations where this may occur are e.g.:
members supporting lifting appliances or rolling loads;
members subjected to repeated stress cycles from vibrating machinery;
members subjected to wind-induced oscillations;
members subject to crowd-induced oscillations;
moving structures (structures subject to inertia forces);
members subjected to fluid flow induced oscillations or wave action.
NOTE The rules for fatigue resistance given in this standard apply generally to high cycle fatigue. For low cycle fatigue,
guidelines are given in Annex F.
(4) The design rules in the other parts of EN 1999 apply.
2.2 Procedures for fatigue design
2.2.1 Safe life design (SLD)
(1) The safe life design method is based on the calculation of damage accumulation during the
structure's design life or comparing the maximum stress range with the constant amplitude limit, using
standard lower bound endurance data and an upper bound estimate of the fatigue loading, all based
on design values. The approach provides a conservative estimate of the fatigue strength and does not
normally depend on in-service inspection for fatigue damage.
6
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SIST EN 1999-1-3:2007/A1:2012
EN 1999-1-3:2007/A1:2011 (E)
NOTE Options considering in-service inspection are given in L1 for use when Annex J resistance data is adopted.
(2) The fatigue design involves prediction of the stress histories at potential crack initiation sites,
followed by counting of load cycles with the associated stress ranges and compilation of stress
spectra. From this information an estimate of the design life is made using the appropriate stress
range endurance data for the construction detail concerned. This method is given in A.2.
(3) The safe life design method may be based on one of two procedures to ensure sufficient
resistance of the component or structure. The procedures are respectively based on that
a) the linear damage accumulation calculation is used, see (4);
b) the equivalent stress range approach is used, see (5)
NOTE A third procedure, for the case where all design stress ranges are less than the design constant amplitude fatigue
limit, is given in L.1(4).
(4) For safe life design based on the assumption of linear damage accumulation (Palmgren-Miner's
summation) the damage value D for all cycles should fulfill the condition:
L
D ≤ 1 (2.1 a)
L,d
where
D = Σn /N is calculated in accordance with the procedure given in A.2.
L,d i i
or
D ≤ D (2.1 b)
L lim
where:
D = Σn /N is calculated in accordance with the procedure given in A.2 with γ = γ = 1,0.
L i i Mf Ff
NOTE The national annex may specify values for D , see L.4. Recommended values of D are given in L.4 for use
lim lim
when resistance data in Annex J is adopted.
(5) In case the design is based on the equivalent stress range approach (∆σ ) the following condition
E,2e
should be fulfilled:
γ ∆σ
Ff E,2e
≤ 1 (2.2)
∆σγ/
C Mf
NOTE Recommended values for γ are given in L.4. For γ , see 2.4.
Mf Ff
2.2.2 Damage tolerant design (DTD)
(1) P A damage tolerant design requires that a prescribed inspection and maintenance programme for
detecting and correcting any fatigue damage is prepared and followed throughout the design life of the
structure. It should provide an acceptable reliability that a structure will perform satisfactorily for its
design life. Prerequisites for use of this method and determination of an inspection strategy are given
in A.3.
NOTE 1 Damage tolerant design may be suitable for application where a safe life assessment shows that fatigue has a
significant effect on design economy and where a higher risk of fatigue cracking during the design life may be justified than is
permitted using safe life design principles. The approach is intended to result in the same reliability level as obtained by using
the approach of safe life design.
NOTE 2 Damage tolerant design may be applied in two different types of approach, DTD-I and DTD-II, see Annex L.
7
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SIST EN 1999-1-3:2007/A1:2012
EN 1999-1-3:2007/A1:2011 (E)
(2) The following guidelines should be considered for the structural layout and detailing:
select details, material and stress levels so that in the event of the formation of cracks a low rate
of crack propagation and a long critical crack length would result;
choose wherever possible a structural concept where in the event of fatigue damage a
redistribution of load effects within the structure or within the cross section of a member can occur
(principle of redundancy);
provide crack-arresting details;
assure that critical components and details are readily inspectable during regular inspection;
ensure that cracks can be kept under control by monitoring or, if needed, that components are
readily repairable or replaceable.
2.2.3 Design assisted by testing
(1) This approach should be used where the necessary loading data, response data, fatigue strength
data or crack growth data are not available from standards or other sources for a particular application,
and for optimisation of construction details. Test data should only be used in lieu of standard data on
condition that they are obtained and applied under controlled conditions.
NOTE Verification of design by testing should be carried out in accordance with Annex C.
2.3 Fatigue loading
2.3.1 Sources of fatigue loading
(1) P All sources of fluctuating stress in the structure should be identified. Common fatigue loading
situations are given in 2.1.1.
NOTE For limitation of fatigue induced by repeated local buckling, see D.3.
(2) The fatigue loading should be obtained from EN 1991 or other relevant European Standard.
NOTE The national annex may give rules for the determination of the fatigue loads for cases not covered by a European
Standard.
(3) Dynamic effects should be taken into account unless already allowed for in the fatigue load effects.
2.3.2 Derivation of fatigue loading
(1) In addition to the fatigue loading standards the following clauses should be considered:
(2) Loading for fatigue should normally be described in terms of a design load spectrum, which defines
a range of intensities of a specific live load event and the number of times that each intensity level is
applied during the structure's design life. If two or more independent live load events are likely to occur
then it will be necessary to specify the phasing between them.
(3) Realistic assessment of the fatigue loading is crucial to the calculation of the life of the structure.
Where no published data for live load exists, fatigue loading data from existing structures subjected to
similar load effects should be used.
(4) By recording continuous strain or deflection measurements over a suitable sampling period, fatigue
loading data should be inferred from subsequent analysis of the structural responses. Particular care
should be taken to assess dynamic magnification effects where load frequencies are close to one of
the natural frequencies of the structure.
NOTE Further guidance is given in Annex C.
8
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SIST EN 1999-1-3:2007/A1:2012
EN 1999-1-3:2007/A1:2011 (E)
(5) The design load spectrum should be selected on the basis that it is an upper bound estimate of the
accumulated service conditions over the full design life of the structure. Account should be taken of all
likely operational and exposure condition effects arising from the foreseeable usage of the structure
during that period.
(6) The confidence limit to be used for the intensity of the design load spectrum should be based on
the mean predicted value plus k standard deviations. The confidence limit to be used for the number
F
of cycles in the design load spectrum should be based on the mean predicted value plus k standard
N
deviations.
NOTE Values of k and k may be defined in the national annex. The numerical values k = 2, and k = 2 are
F N F N
recommended. See also NOTE 2 under 2.4 (1).
2.3.3 Equivalent fatigue loading
(1) A simplified equivalent fatigue loading may be used if the following conditions are satisfied:
a) the structure falls within the range of basic structural forms and size for which the equivalent
fatigue loading was originally derived;
b) the real fatigue loading is of similar intensity and frequency and is applied in a similar way to that
assumed in the derivation of the equivalent fatigue loading;
c) the values of m , m , N and N , see Figure 6.1, assumed in the derivation of equivalent fatigue
1 2 D L
loading are the same as those appropriate to the construction detail being assessed;
NOTE Some equivalent fatigue loads may have been derived assuming a simple continuous slope where m = m and
2 1
∆σ = 0. For many applications involving numerous low amplitude cycles this will result in a very conservative estimate of life.
L
d) the dynamic response of the structure is sufficiently low that the resonant effects, which will be
affected by differences in mass, stiffness and damping coefficient, will have little effect on the
overall Palmgren-Miner summation.
(2) In the event that an equivalent fatigue loading is derived specifically for an aluminium alloy
structural application, all the matters addressed in (1) above should be taken into account.
2.4 Partial factors for fatigue loads
(1) Where the fatigue loads F have been derived in accordance with the requirements of 2.3.1 (2)
Ek
and 2.3.2 a partial factor should be applied to the loads to obtain the design load F .
Ed
F = γ F (2.4)
Ed Ff Ek
where
γ is the partial factor for fatigue loads.
Ff
NOTE 1 The partial factors may be defined in the national annex. A value of γ = 1,0 is recommended.
Ff
NOTE 2 Where fatigue loads have been based on confidence limits other than those in 2.3.2 (6), recommended values for
partial factors on loads are given in Table 2.1. Alternative values may be specified in the national annex.
9
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SIST EN 1999-1-3:2007/A1:2012
EN 1999-1-3:2007/A1:2011 (E)
Table 2.1 — Recommended partial factors γγγγ for intensity and number of cycles in the fatigue
Ff
load spectrum
γ
Ff
k
...
SLOVENSKI STANDARD
SIST EN 1999-1-3:2007/kFprA1:2011
01-februar-2011
(YURNRG3URMHNWLUDQMHNRQVWUXNFLML]DOXPLQLMHYLK]OLWLQGHO.RQVWUXNFLMH
REþXWOMLYHQDXWUXMDQMH
Eurocode 9: Design of aluminium structures - Part 1-3: Structures susceptible to fatigue
Eurocode 9: Bemessung und Konstruktion von Aluminiumtragwerken - Teil 1-3:
Ermüdungsbeanspruchte Tragwerke
Eurocode 9: Calcul des structures en aluminium - Partie 1-3: Structures sensibles à la
fatigue
Ta slovenski standard je istoveten z: EN 1999-1-3:2007/FprA1
ICS:
91.010.30 7HKQLþQLYLGLNL Technical aspects
91.080.10 Kovinske konstrukcije Metal structures
SIST EN 1999-1-3:2007/kFprA1:2011 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 1999-1-3:2007/kFprA1:2011
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SIST EN 1999-1-3:2007/kFprA1:2011
EUROPEAN STANDARD
FINAL DRAFT
EN 1999-1-3:2007
NORME EUROPÉENNE
EUROPÄISCHE NORM
FprA1
November 2010
ICS 91.010.30; 91.080.10
English Version
Eurocode 9: Design of aluminium structures - Part 1-3:
Structures susceptible to fatigue
Eurocode 9: Calcul des structures en aluminium - Partie 1- Eurocode 9: Bemessung und Konstruktion von
3: Structures sensibles à la fatigue Aluminiumtragwerken - Teil 1-3: Ermüdungsbeanspruchte
Tragwerke
This draft amendment is submitted to CEN members for unique acceptance procedure. It has been drawn up by the Technical Committee
CEN/TC 250.
This draft amendment A1, if approved, will modify the European Standard EN 1999-1-3:2007. If this draft becomes an amendment, CEN
members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of this amendment
into the relevant national standard without any alteration.
This draft amendment 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 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland 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
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1999-1-3:2007/FprA1:2010: E
worldwide for CEN national Members.
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SIST EN 1999-1-3:2007/kFprA1:2011
EN 1999-1-3:2007/FprA1 (E)
Foreword
This document (EN 1999-1-3:2007/FprA1:2010) has been prepared by Technical Committee
CEN/TC 250 “Structural Eurocodes”, the secretariat of which is held by BSI.
This document is currently submitted to the Unique Acceptance Procedure.
2
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SIST EN 1999-1-3:2007/kFprA1:2011
EN 1999-1-3:2007/FprA1 (E)
1 Modification to 1.5.2.34
Replace 1.5.2.34 with the following: "
1.5.2.34
safe life
period of time for which a structure is estimated to perform safely with an acceptable probability that
failure by fatigue cracking will not occur, when using the safe life design method".
2 Modification to 1.6
In 1.6 replace
"∆σ nominal stress range (normal stress)
∆τ effective shear stress range
6
∆σ reference fatigue strength at 2x10 cycles (normal stress)
C
∆σ constant amplitude fatigue limit
D
∆σ equivalent constant amplitude stress range related to N
E max
6
∆σ equivalent constant amplitude stress range related to 2x10 cycles
E,2
∆σ cut-off limit
L
∆σ fatigue strength (normal stress)
R
σ , σ maximum and minimum values of the fluctuating stresses in a stress cycle
max min
σ mean stress."
m
with
"∆σ nominal stress range (normal stress)
NOTE ∆σ refers either to action effects or to fatigue strength depending on context.
∆τ effective shear stress range
6
∆σ reference fatigue strength at 2 × 10 cycles (normal stress)
C
∆σ constant amplitude fatigue limit
D
∆σ nominal stress range from fatigue actions
E
∆σ equivalent constant amplitude stress range related to N
E,Ne max
6
∆σ equivalent constant amplitude stress range related to 2 × 10 cycles
E,2e
cut-off limit
∆σ
L
∆σ fatigue strength (normal stress)
R
σ , σ maximum and minimum values of the fluctuating stresses in a stress cycle
max min
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SIST EN 1999-1-3:2007/kFprA1:2011
EN 1999-1-3:2007/FprA1 (E)
σ mean stress."
m
and add
"D design fatigue damage value calculated for the full design life".
L.d
3 Modification to Clause 2
Replace Clause 2 with the following: "
2 Basis of design
2.1 General
2.1.1 Basic requirements
(1) P The aim of designing a structure against the limit state of fatigue is to ensure, with an acceptable
level of probability, that its performance is satisfactory during its entire design life, such that the
structure shall not fail by fatigue nor shall it be likely to require undue repair of damage caused by
fatigue during the design life. The design of aluminium structures against the limit state of fatigue may
be based on one of following methods:
a) safe life design (SLD) (see 2.2.1);
b) damage tolerant design (DTD) (see 2.2.2).
Either of methods a) and b) may be supplemented or replaced by design assisted by testing (see
2.2.3).
NOTE The national annex may specify conditions for the application for the above methods of design.
(2) The method for design against fatigue should be selected taking the use of the structure into
account, considering the consequence class fixed for the components of the structure. In particular the
accessibility for inspection of components and details where fatigue cracks are likely to occur should
be considered.
(3) Fatigue assessment of components and structures should be considered in cases where the loads
are frequently changing, particularly if reversing. Common situations where this may occur are e.g.:
members supporting lifting appliances or rolling loads;
members subjected to repeated stress cycles from vibrating machinery;
members subjected to wind-induced oscillations;
members subject to crowd-induced oscillations;
moving structures (structures subject to inertia forces);
members subjected to fluid flow induced oscillations or wave action.
NOTE The rules for fatigue resistance given in this standard apply generally to high cycle fatigue. For low cycle fatigue,
guidelines are given in Annex F.
(4) The design rules in the other parts of EN 1999 apply.
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SIST EN 1999-1-3:2007/kFprA1:2011
EN 1999-1-3:2007/FprA1 (E)
2.2 Procedures for fatigue design
2.2.1 Safe life design (SLD)
(1) The safe life design method is based on the calculation of damage accumulation during the
structure's design life or comparing the maximum stress range with the constant amplitude limit, using
standard lower bound endurance data and an upper bound estimate of the fatigue loading, all based
on design values. The approach provides a conservative estimate of the fatigue strength and does not
normally depend on in-service inspection for fatigue damage.
NOTE Options considering in-service inspection are given in L1.
(2) The fatigue design involves prediction of the stress histories at potential crack initiation sites,
followed by counting of load cycles with the associated stress ranges and compilation of stress
spectra. From this information an estimate of the design life is made using the appropriate stress
range endurance data for the constructional detail concerned. This method is given in A.2.
(3) The safe life design method may be based on one of two procedures to ensure sufficient
resistance of the component or structure. The procedures are respectively based on that
a) the linear damage accumulation calculation is used, see (4);
b) the equivalent stress range approach is used, see (5)
NOTE A third procedure, for the case where all design stress ranges are less than the design constant amplitude fatigue
limit, is given in L.1(4).
(4) For safe life design based on the assumption of linear damage accumulation (Palmgren-Miner's
summation) the damage value D for all cycles should fulfill the condition:
L
D ≤ 1 (2.1 a)
L,d
where
D = Σn /N is calculated in accordance with the procedure given in A.2.
L,d i i
or
D ≤ D (2.1 b)
L lim
where:
D = Σn /N is calculated in accordance with the procedure given in A.2 with γ = γ = 1,0.
L i i Mf Ff
NOTE The national annex may specify values for D , see L.4. Recommended values of D are given in L.4 for use
lim lim
when resistance data in Annex J is adopted.
(5) In case the design is based on the equivalent stress range approach (∆σ ) the following condition
E,2e
should be fulfilled:
γ ∆σ
Ff E,2e
≤ 1 (2.2)
∆σγ/
C Mf
NOTE Recommended values for γ are given in L.4. For γ , see 2.4.
Mf Ff
2.2.2 Damage tolerant design (DTD)
(1) P A damage tolerant design requires that a prescribed inspection and maintenance programme for
detecting and correcting any fatigue damage is prepared and followed throughout the design life of the
5
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EN 1999-1-3:2007/FprA1 (E)
structure. It should provide an acceptable reliability that a structure will perform satisfactorily for its
design life. Prerequisites for use of this method and determination of an inspection strategy are given
in A.3.
NOTE 1 Damage tolerant design may be suitable for application where a safe life assessment shows that fatigue has a
significant effect on design economy and where a higher risk of fatigue cracking during the design life may be justified than is
permitted using safe life design principles. The approach is intended to result in the same reliability level as obtained by using
the approach of safe life design.
NOTE 2 Damage tolerant design may be applied in two different types of approach, DTD-I and DTD-II, see Annex L.
(2) The following guidelines should be considered for the structural layout and detailing:
select details, material and stress levels so that in the event of the formation of cracks a low rate
of crack propagation and a long critical crack length would result;
choose wherever possible a structural concept where in the event of fatigue damage a
redistribution of load effects within the structure or within the cross section of a member can occur
(principle of redundancy);
provide crack-arresting details;
assure that critical components and details are readily inspectable during regular inspection;
ensure that cracks can be kept under control by monitoring or, if needed, that components are
readily repairable or replaceable.
2.2.3 Design assisted by testing
(1) This approach should be used where the necessary loading data, response data, fatigue strength
data or crack growth data are not available from standards or other sources for a particular application,
and for optimisation of constructional details. Test data should only be used in lieu of standard data on
condition that they are obtained and applied under controlled conditions.
NOTE Verification of design by testing should be carried out in accordance with Annex C.
2.3 Fatigue loading
2.3.1 Sources of fatigue loading
(1) P All sources of fluctuating stress in the structure should be identified. Common fatigue loading
situations are given in 2.1.1.
NOTE For limitation of fatigue induced by repeated local buckling, see D.3.
(2) The fatigue load should be obtained from EN 1991 or other relevant European Standard.
NOTE The national annex may give rules for the determination of the fatigue loads for cases not covered by a European
Standard.
(3) Dynamic effects should be taken into account unless already allowed for in the fatigue load effects.
2.3.2 Derivation of fatigue loading
(1) In addition to the fatigue load standards the following clauses should be considered:
(2) Load for fatigue should normally be described in terms of a design load spectrum, which defines a
range of intensities of a specific live load event and the number of times that each intensity level is
applied during the structure's design life. If two or more independent live load events are likely to occur
then it will be necessary to specify the phasing between them.
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EN 1999-1-3:2007/FprA1 (E)
(3) Realistic assessment of the fatigue load is crucial to the calculation of the life of the structure.
Where no published data for live load exist, resort should be made to obtaining data from existing
structures subjected to similar effects.
(4) By recording continuous strain or deflection measurements over a suitable sampling period, load
data should be inferred by subsequent analysis of the response. Particular care should be taken to
assess dynamic magnification effects where load frequencies are close to one of the natural
frequencies of the structure.
NOTE Further guidance is given in Annex C.
(5) The design load spectrum should be selected on the basis that it is an upper bound estimate of the
accumulated service conditions over the full design life of the structure. Account should be taken of all
likely operational and exposure condition effects arising from the foreseeable usage of the structure
during that period.
(6) The confidence limit to be used for the intensity of the design load spectrum should be based on
the mean predicted value plus k standard deviations. The confidence limit to be used for the number
F
of cycles in the design load spectrum should be based on the mean predicted value plus k standard
N
deviations.
NOTE Values of k and k may be defined in the national annex. The numerical values k = 2, and k = 2 are
F N F N
recommended. See also NOTE 2 under 2.4 (1).
2.3.3 Equivalent fatigue loading
(1) A simplified equivalent fatigue load may be used if the following conditions are satisfied:
a) the structure falls within the range of basic structural forms and size for which the equivalent
fatigue load was originally derived;
b) the real fatigue load is of similar intensity and frequency and is applied in a similar way to that
assumed in the derivation of the equivalent fatigue load;
c) the values of m , m , N and N , see Figure 6.1, assumed in the derivation of equivalent fatigue
1 2 D L
load are the same as those appropriate to the constructional detail being assessed;
NOTE Some equivalent fatigue loads may have been derived assuming a simple continuous slope where m = m and
2 1
∆σ = 0. For many applications involving numerous low amplitude cycles this will result in a very conservative estimate of life.
L
d) the dynamic response of the structure is sufficiently low that the resonant effects, which will be
affected by differences in mass, stiffness and damping coefficient, will have little effect on the
overall Miner summation.
(2) In the event that an equivalent fatigue load is derived specifically for an aluminium alloy structural
application, all the matters addressed in (1) above should be taken into account.
2.4 Partial factors for fatigue loads
(1) Where the fatigue loads F have been derived in accordance with the requirements of 2.3.1 (2)
Ek
and 2.3.2 a partial factor should be applied to the loads to obtain the design load F .
Ed
F = γ F (2.4)
Ed Ff Ek
where
γ is the partial factor for fatigue loads.
Ff
NOTE 1 The partial factors may be defined in the national annex. A value of γ = 1,0 is recommended.
Ff
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EN 1999-1-3:2007/FprA1 (E)
NOTE 2 Where fatigue loads have been based on other confidence limits than those in 2.3.2 (6), recommended values for
partial factors on loads are given in Table 2.1. Alternative values may be specified in the national annex.
Table 2.1 — Recommended partial factors γγγγ for intensity and number of cycles in the fatigue
Ff
load spectrum
γ
Ff
k
F
k = 0 k = 2
N N
0 1,5 1,4
1 1,3 1,2
2 1,1 1,0
2.5 Execution requirements
(1) EN 1090-3 requires execution classes to be selected. These may be related to service category.
NOTE Guidance on selection of execution class and service category is given in EN 1999-1-1. Guidance on utilization
grade is given in L.5.".
4 Modification to 5.8.1 (2)
Replace 5.8.1 (2) with the following: "
(2) The design value of stress range to be used for the fatigue assessment should be the stress
6
ranges γ ∆σ corresponding to N = 2 × 10 cycles.".
Ff E,2e C
5 Modification to 5.8.2 (1)
Replace 5.8.2 (1) with the following: "
(1) The design value of nominal stress ranges γ ⋅∆σ should be determined as follows:
Ff E,2e
γ ∆σ =λ ×λ ×Kλ ×Kλ ×∆σ (γ Q ) for nominal stress (5.1)
Ff E,2e 1 2 i n Ff k
*
γ ∆σ =K γ ∆σ for modified nominal stress (5.2)
Ff E,2e gt Ff
E,2e
where
∆σ(γ Q ) is the stress range caused by the fatigue loads specified in EN 1991;
Ff k
λ are damage equivalent factors depending on the load situation and the structural
i
characteristics as well as other factors;
K is the stress concentration factor to take account of the local stress magnification in relation
gt
to detail geometry not included in the reference ∆σ -N-curve, see 5.3.2.1.
C
NOTE 1 The values of λ may be given in the national annex.
i
NOTE 2 λ –values for steel components may not be applicable for aluminium components.".
i
6 Modifications to 6.2.1 (2)
In 6.2.1 (2), replace
"∆σ is the stress range for the principal stresses at the constructional detail and is constant for all
i
cycles"
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SIST EN 1999-1-3:2007/kFprA1:2011
EN 1999-1-3:2007/FprA1 (E)
with
"∆σ is the constant stress range for the principal stresses in the constructional detail for n cycles".
i i
and replace NOTE 2 with the following: "
NOTE 2 The value of the partial factor γ for a specific constructural detail type may be defined in the national annex.
Mf
Recommended values are given in L.4."
to read as follows
5 6
"(2) The fatigue design relationship for endurances in the range between 10 to 5 × 10 cycles is defined
by the equation:
m
1
∆σ 1
6 c
N = 2×10 (6.1)
i
∆σ γ γ
i Ff Mf
where
N is the predicted number of cycles to failure of a stress range ∆σ
i i
6
∆σ is the reference value of fatigue strength at 2 × 10 cycles, depending on the detail category,
c
where standardized values are given in Table 6.1
∆σ is the constant stress range for the principal stresses in the constructional detail for n cycles
i i
m is the inverse slope of the ∆σ-N curve, depending on the detail category
1
γ is the partial factor allowing for uncertainties in the loading spectrum an
...
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