ASD-STAN PREN 2002-5-1995 Aerospace Series Test Methods for Metallic Materials Part 5 Uninterrupted Creep and Stress-Rupture Testing Edition P2《航空航天系列 金属材料的试验方法 第5部分 不连续蠕变和应变-断裂试验 .pdf

1、AECMA PRENx2002 PARTx5 95 = 1012311 0009769 419 Edition approved for publication AECMA STANDARD prEN 2002 NORME AECMA Part 5 Edition P 2 October 1995 AECMA NORM PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Gulledelle 94 - B-1200 BRUXELLES - Tel. (32) 2 775 81 10 - Fax. (32)

2、2 775 81 11 C5 Chairman Comments should be sent within six months after the date of publication to ICs : Supersedes Issue P 1 December 1993 Descriptors : ENGLISH VERSION Aerospace series Test methods for metallic materials Part 5 : Uninterrupted creep and stress-rupture testing b Srie arospatiale Mt

3、hodes dessais applicables aux matriaux mtalliques Partie 5 : Essai non interrompu de fluage et essai de rupture par fluage Luft- und Raumfahrt Prfverfahren fr metallische Werkstoffe Teil 5 : Kriech- und Zeitstandversuch unter konstanter Zugbeanspruchung This “Aerospace Series“ Prestandard has been d

4、rawn up under the responsibility of AECMA (Th European Association of Aerospace Industries). It is published on green paper for the needs o AECMA-Members. It has been technically approved by the experts of the concerned Technica Committee following comment by the Member countries. an extent that int

5、erchangeability is affected, physically or functionally, without re-identifica tio of the standard. After examination and signature of the AECMA Standard Checking Centre (NPS) and forma agreement of the Official Services of the Member countries it will be submitted as a draf European Standard to CEN

6、 (European Committee for Standardization) for formal vote. Subsequent to the publication of this Prestandard, the technical content shall not be changed t J 1995-10-31 AECMA Gulledelle 94 8-1 200 BRUXELLES M. Odorico I I aecma 199E AECMA PREN*ZOOZ PART*5 95 I 1012311 O009770 130 Page 2 prEN 2002-5 :

7、 1995 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Contents list Scope References Principle Symbols Definitions Specification of test requirements Testing equipment Proportional test pieces Non-proportional test pieces Preparation of test piece from sample Measurement of cross-sectional area Marking

8、 the original gauge length Heating of test piece Temperature control and observations Loading of the test piece Stress rupture test Creep strain test Test report I 1 i ! AECMA PREN*2002 PARTr5 95 H 10123Ll 0009771 077 Page 3 prEN 2002-5 : 1995 I Scope This standard applies to uninterrupted constant-

9、load tensile creep strain and stress-rupture testing of metallic materials governed by aerospace standards. It defines the properties that may need to be determined and the terms used in describing tests and test pieces. It specifies the dimensions of test pieces and the method of testing. The durat

10、ion of the creep strain and stress-rupture tests complying with this standard shall be less than 1 O O00 h and at temperatures not exceeding 1 1 OOOC. This standard may also apply to metallic materials for test durations exceeding 10 O00 h and/or for test temperatures exceeding 1 1 OOOC providing th

11、at previous agreement has been reached between the manufacturer and the purchaser. 2 Normative references This Standard incorporates by dated or undated reference provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are l

12、isted hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 10002-2 Metallic materials - Te

13、nsile testing - Part 2 : Verification of the force measuring system of the tensile testing machines EN 10002-4 Metallic materials - Tensile test - Part 4 : Verification of extensometers used in uniaxial testing ASTM E 1 O1 2 Verification of specimen alignment under tensile loading ) 1 ) Published by

14、 American Society for Testing and Materials (ASTM), 191 6 Race Street, Philadelphia, PA 19103. AECMA PRENm2002 PART*5 95 LOL231L 0009772 TO3 W Thickness of test section of test piece of rectangular cross-section Percentage elongation after rupture Percentage strain during testing Percentage total pl

15、astic strain Notch angle Width of test section of test piece of rectangular cross-section Diameter of test section of test piece of circular cross-section Diameter of test piece at root of notch Diameter of the parallel portion of a notched test piece of circular cross- section Theoretical stress co

16、ncentration factor of a notched test piece Parallel length Extensometer gauge length (Leo = initial ; Leu = final) Basis gauge length for elongation calculations Extension of extensometer gauge length Measurement gauge length Parallel length of the test piece containing the notch Shoulder gauge leng

17、th for test without extensometer on the parallel length (Lso = initial ; Lsu = final) Total length of the test piece Final measurement length after rupture Transition radius Notch root radius Stress, based on room temperature cross-sectional area Original room temperature cross-sectional area of tes

18、t section Minimum cross-sectional area of test section after rupture Time of the test under specified conditions for temperature and stress Continued Page 4 DrEN 2002-5 : 1995 3 Principle The test consists in maintaining a test piece at a uniform temperature and subjecting it to a constant tensile f

19、orce at that temperature in order to determine specified properties. 4 Symbols See table 1 and figures 1 to 5. Table 1 Symbol a A A f AP a. b d dn Dn rn 6 SO SU Unit I Designation mm % % % O mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm M Pa mm2 mm2 h AECMA PRENU2002 PARTUS 95 LOI12311 0009773 94T H

20、Symbol tP tr QT Z Unit h h OC 96 5 Definitions 5.1 Test piece Page 5 prEN 2002-5 : 1995 3 Table 1 (concluded) Designation Time to specified total plastic strain Time to rupture Test temperature Percentage reduction of area after rupture Portion of the test sample on which the creep strain or stress-

21、rupture test is carried out (see figures 1 to 5). 5.2 Proportional test piece A test piece having an original basis gauge length (Lo = Leos or L,.) which bears a specified relationship to the cross-sectional area. This ensures that comparable values for percentage elongation after rupture (A) are ob

22、tained from test pieces of different size but having the same relationship. The relationship Lo = 5,65 6o which for test pieces of circular cross section gives a value of Lo = 5 do has been accepted by international agreement and is preferred in the use of this standard. The relationship is indicate

23、d in the symbol for percentage elongation after rupture (A) as a subscript, e.g. A, representing the ratio Lo/d. 5.3 Non-proportional test piece In cases where the original basis gauge length has not the defined relationship to the cross-sectional area, a subscript shall be used with the symbol for

24、elongation A to indicate the gauge length, .e. A40mm. 5.4 Gauge length A length of the test piece on which elongation is measured at any moment during the test. 5.4.1 Measurement gauge length (L,) e The measurement gauge length shall be defined as either the extensometer gauge length Leo for test pi

25、eces measured with extensometers gripping the parallel portion of the specimen or small annular ridges, when these are used, or the shoulder gauge length Ls for test pieces where extension is measured between points including the transition radii and/or gripping portions of the test piece. The measu

26、rement gauge length (Lm) is to be used only for the numerator in elongation calculations; that is, the change in length of that part of the test piece defined as Lm, whereas the basis gauge length, .e. Leo# or L,., is to be used for the denominator. 5.4.2 Extensometer gauge length (Leo) Where an ext

27、ensometer is attached directly to the parallel portion of the unloaded test piece, the extensometer gauge length Leo is equal to the distance between the points of contact of the extensometer measured at room temperature, and shall also be used as the corresponding basis gauge length. Alternatively,

28、 the extensometer may be attached to annular ridges on the parallel portion. In these cases, the basis gauge length to be used as the denominator in the elongation calculations shall be the equivalent gauge length, calculated as shown (see 5.4.3). AECMA PREN*Z002 PART*S 95 LOL23LL 0009774 BBb = Page

29、 6 prEN 2002-5 : 1995 5.4.3 Basis gauge length for elongation calculations (Leo.or Ls a) The equivalent gauge length, .e. the parallel length which would give the same extension, including all loaded portions of the test piece between the measuring points, except the gripped ends. It shall be used a

30、s the denominator in all elongation calculations. For stress-rupture test pieces it is recommended that Leo -, or Ls be calculated from the following equation: Leo-or Ls- = Lc + 2 (do/di)2n x Li = 5,65 6o i= 1 Where : Lc is the parallel length between the annular ridges or test piece ends, with a di

31、ameter do, k is the number of sections of length Li with increasing diameter of di at the two transition radii. The correct Lc shall be selected, so that the effective gauge length equals 5,65 .JS0. It is recommended to use n = 6 as a basis for comparison, although the actual n for many aerospace ma

32、terials is 6. This is based on the “power law“ creep relationship : 5.4.4 Shoulder gauge length Ls) Where the extension is measured at the test piece ends, or between reference marks on the enlarged ends of the test piece, the shoulder gauge length (L,) shall be denoted. The basis gauge length shall

33、 be calculated as in 5.4.3 and based on room temperature measurements, including all loaded portions of the test piece between the measuring points, except the gripped ends. 5.5 Parallel length (L,) The length of the parallel portion of the test piece. For some test pieces, Lc will be less than Lm,

34、the applicable original gauge length. 5.6 Extension (ALe) The increase of the extensometer gauge length from the initial length, Leo or Leo#, indicated at the test temperature before loading, to a value Le at a given moment during the test. 5.7 Final measurement length after rupture (Lu) The measure

35、 of the applicable gauge length (Leu or Lsu) after the test piece has ruptured, measured at room temperature. This may include the unstressed test piece ends, if the total length is used as the gauge length. 5.8 Percentage elongation after rupture (A) The permanent increase in length (Lu - Lm) of th

36、e applicable measurement gauge length, expressed as a percentage of the original applicable basis gauge length (Leo or Ls e), for example: A= Lu-Leo x 100, all measurements being made at room temperature. Leo 5.9 Percentage extension during testing (Af) The increase of the applicable gauge length, a

37、t a given time under full load, expressed as a percentage of the original applicable gauge length. The initial plastic strain during loading shall not be included in Af, just the elongation after attainment of full load (see figure 61. - AECMA PRENx2002 PARTxS 95 10123LL 0009775 i12 I 1 Page 7 prEN

38、2002-5 : 1995 5.1 O The total plastic extension of the original applicable measurement gauge length (Leo or Ls) inclusive of any plastic extensions during loading (.e. the total extension excluding elastic extensions, expressed as a percentage of the original applicable basis gauge length (see figur

39、es 6 and 7). Percentage total plastic strain (Ap) 5.1 l Original section (So) The cross-sectional area of the gauge length of the test piece, determined before testing. 5.12 Final section (Su) The minimum cross-sectional area of the test piece, after rupture. 5.13 Percentage reduction of area after

40、rupture (2) The maximum decrease of the cross-sectional area (So - Su) expressed as a percentage of the original cross-sectional area (So), .e. Z = so - su x 100 SO 5.14 Stress (a) The force on the test piece divided by the original cross-sectional area of the parallel portion. It should be noted th

41、at the thermal expansion of the test piece during heating increases the effective cross- sectional area. The effective stress is therefore slightly less than 0, which is based on room temperature. 5.15 Rupture Complete fracture of the test piece within the original gauge length under constant force

42、and at constant temperature. 5.16 Time to rupture (t,) The total time, at the test temperature and the test force, to the rupture of the test piece (see figure 7) 5.17 Time to specified total plastic strain (t,) The total time, at the test temperature and including the portion of the loading time af

43、ter the loading curve deviates from an extension of the linear-elastic modulus line, until the specified total plastic strain (Ap) is reached (see figure 6). 5.1 8 Theoretical stress concentration factor (KJ The ratio of the greatest stress in the region of a notch as determined by the theory of ela

44、sticity to the corresponding nominal stress. In formula : Kt=- Opeak Onom. Where : Kt speak is the peak stress by notch Onom. is the nominal stress is the theoretical stress concentration factor AECMA PREN*2002 PART*5 75 LOL231L 0007776 659 Page 8 prEN 2002-5 : 1995 6 Specification of test requireme

45、nts The material standard shall state the following : - type of test piece see 8 and 9) ; - specified test temperature (0,) ; - specified test stress (o) ; - time the test piece shall be simultaneously under the specified conditions of temperature and stress it) ; - maximum soaking time where applic

46、able see 13) ; - criterion of acceptance which may be one of the following : a) a statement of the percentage total plastic strain Ap or percentage total strain Af that shall not be exceeded ; b) a requirement that the test piece shall not rupture before the end of the test time specified above ; c)

47、 any other requirement specified, such as minimum percent elongation at fracture. 7 Testing equipment 7.1 Load calibration The testing machine shall be calibrated at intervals not exceeding one year in accordance with EN 10002-2 and shall be at grade 1 ,O or better. The machine should be equipped wi

48、th a device which minimizes shock when the test piece ruptures (only with more than 1 test device). 7.2 Strain calibration The instruments used for the measurements of creep strain shall have an accuracy within 0,006 % of the gauge length or 1 % of the total creep strain to be measured, whichever is

49、 the greater. They shall be calibrated at intervals not exceeding one year in accordance with EN 10002-4. class 0.5. Calibration should be checked at more frequent. More frequent spot checks are recommended. 7.3 Calibration for long-term tests Where long term tests are carried out in excess of one year the testing machine and extensometer shall be calibrated immediately before and on the completion of such tests. 7.4 Extensometer requirements If an extensometer is used it shall be capable of measuring the extension on opposite sides of the test piece, and the readin