JIS-Z-2273-1978-R2005-ENG.pdf
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1、UDC 620.178.3:669.017 7 J I S Z*Z273 78 W 4933b08 0075459 8 JIS . 4 % a e I i JAPANESE I NDUSTRIAL STANDARD General Rules for Fatigue Testing of Metals Translated and Published by Japanese Standards Association Printed in Japan J I S Z*2273 78 4933608 00754b0 4 , Translation without guarantee standa
2、rd in Japanese is to be evidence i n the event of aqy doubt arising, the original -,-,- UDC 620.178.3 :669. O 17 J I S Z*2273 78 4933b08 0075463 b W a JAPANESE INDUSTRIAL STANDARD J I S General Rules for Fatigue Testing of Metals Z 2273-1978 1. .Scope This Japanese Industrial Standard specifies the
3、general rules for fatigue testing of metals by the use of standard test pieces in the atmospheric air at room temperature, covering fatigue life under the number of stress cycles not less than lo4 times. 2, Definitions 2.1 Terms Concerning Stress and Number of Stress Cycles 2.1.1 Nominal Stress Stre
4、ss calculated elastically without taking into con- The normal stress sideration the stress concentration due to notches or others. is expressed by U and the shearing stress by T . Applicable Standard: J E 3 Z 8401-Rules for Rounding Off of Numerical Values -,-,- 2 J I S Z*2273 78 4933608 00754b2 8 W
5、 Z 2273-1978 2.1.2 Varying Stress Stress the magnitude of which changes with time (Fig. 1). 2.1.3 Repeated Stress Stress varying simply and periodically between the constant maximum and minimum values (Fig, 2). Fig. 1. Varying Stress Rig. 2. Repeated Stress + - Time - Time 2.1.4 Maximum Stress urnox
6、, Tmax The highest algebraic value of repeated stress (Fig. 2). 2.1.5 Minimum Stress umins rmln The lowest algebraic value of repeated In the case of tensile and compressive stresses, the maximum and minimum stresses take, considering sign, positive sign for tensile stress and negative sign for comp
7、ressivestress. In the case of shearing stress, if one direction takes positive sign, so the opposite direction negative sign, stress (Fig. 2). Remark: 2.1.6 Mean Stress um, rm One-half of the algebraic sum of the maximum and minimum stresses of the repeated stresses (Fig. 2). 2.1.7 Stress Amplitude
8、ou, ru One-half of the algebraic difference between the maximum and minimum stresses of the repeated stresses (Fig. 2). 2.1.8 Range of Stress UR, r The algebraic difference between the maximum and minimum stresses of the repeated stresses (Fig. 2). 2.1.9 Stress Amplitude-Mean Stress Ratio A The stre
9、ss amplitude to the mean stress. U Ta U m A = L or A=- T m 2.1.10 Minimum-Maximum Stress Ratio R The a minimum stress to the maximum stress. algebraic ratio of the gebraic ratio of the -,-,- J I S Z*Z273 78 4933b08 0075463 T 3 Z 2273-1978 2.1.11 Symmetrical Reversed Stress Stress alternating repeate
10、dly between two values opposite in sign but equal in magnitude (where uin=O or ra=O,Fig, 3). 2.1.12 Asymmetrical Reversed Stress Stress alternating repeatedly between the positive maximum value and the negative minimum value, the abso- lute values of which are different (where O or rmra, Fig. 6). Fi
11、g. 5. Completely Fluctuating Fig. 6. Partially Fluctuating 2.1.15 Number of Stress Cycles n The number of stress during the fatigue test. - Time cycles applied 2.1.16 Endurance N The number of stress cycles to fatigue failure. 2.1.17 Cycle Ratio 72/N The ratio of the applied stress cycles, 72 to cyc
12、les to failure, N. -,-,- 4 JIS Z*Z273 78 9 4933b08 00754b4 I M I Z 2273-1978 2.1.18 Shape Coefficient a The quotient obtained by dividing the elastically calculated maximum stress concerning a stress concentrated part by the nominal stress of the same part, when a load is applied on a notched test p
13、iece. 2.2 Terms Concerning the Fatigue Strength 2.2.1 S-N Curve (Stress-number of stress cycles curve) The curve drawn by plotting the stress as ordinate and the number of stress cycles to failure (including the number of stress cycles where the test is completed without failure) as abscissa. 2.2.2
14、Fatigue Limit The upper limit value of the stress up to which the test piece can endure an infinite number of stress cycles. shall be made as shown in 2.2.3 to 2.2.10 according to the type of test. The expression Remark: The above term means an ideal case without dispersion of test values. Usually,
15、the test values obtained in the vicinity of the fatigue limit show dispersion, so that the fatigue limit shall be obtained statistically. 2.2.3 Reversed Tension and Compression Fatigue Limit u# The fatigue To be limit when the reversed tensile and compressive stresses are applied. expressed by the s
16、tress amplitude. 2.2.4 Fluctuating Tension Fatigue Limit GU The fatigue limit when the fluctuating tensile stress is applied To be expressed by twice the stress am- pi itude . 2.2.5 Fluctuating Compression Fatigue Limit u-U The fatigue limit when the fluctuating compressive stress is applied. stress
17、 amplitude. To be expressed by twice the 2.2.6 Rotating Bending Fatigue Limit U W The fatigue limit when the rotating bending stress is applied. To be expressed by the stress amplitude. 2.2.7 Reversed Plane Bending Fatigue Limit WP The fatigue limit when the reversed plane bending stress in applied.
18、 amplitude. To be expressed by the stress 2.2.8 Fluctuating Plane Bending Fatigue Limit UUP The fatigue limit when the fluctuating plane bending stress is applied. stress amplitude. To be expressed by twice the 2.2.9 Reversed Twisting Fatigue Limit Tio The fatigue limit when the reversed twisting st
19、ress is applied. To be expressed by the stress amplitude. 2.2.10 Fluctuating Twisting Fatigue Limit TU The fatigue limit when the fluctuating twisting stress is applied. amplitude. To be expressed by twice the stress 2.2.11 Fatigue Limit Diagram The diagram showing the status of change in the fatigu
20、e limit due to the influence of the mean stress or the stress ratio. 2.2.12 Fatigue Limit Ratio The quotient obtained by dividing the fatigue limit by the tensile strength. 2.2.13 Endurance Limit The upper limit value of the stress up to which the test pieces can endure the designated number of stre
21、ss cycles. endurance limit, the specifications of 2 . 2 . 3 to 2.2.12 apply as appropriate. In this case, the number of stress cycles shall be shown in parentheses at the end. For the 2.2.14 Fatigue Strength A general nomination for the fatigue limit and the endurance limit, 2.2.15 Fatigue Strength
22、of a Notched Test Rece The fatigue strength of a notched test piece expressed by the nominal stress. a 2.2.16 Notch Coefficient (Fatigue Strength Reduction Factor) , The quotient obtained by dividing the fatigue strength of the plain polished test piece by the fatigue strength of a notched test piec
23、e. 2.2.17 Notch Sensitivity Coefficient i7 A coefficient to express the degree of coincidence of the notch coefficient based on the shape, dimensions, and the material quality of a notched test piece with the shape coefficient (the sensitivity against the notch). 3. Test Pieces 3 . 1 The test pieces
24、 shall, as a rule; be of circular cross section or of 0 plate type. 3.2 In preparing test pieces by machining through cutting or grinding, pre- cautions should be taken to ensure that the process does not cause on the test piece tearings and appreciable work strains, and also that the test pieces ar
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