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1、International Standard ) 458 I 1 0 0 4 eg!b ,NTERNAT,ONA ORCAN,ZAT,ON FOR STANDARDIZATIONW.4ElYHAPOHAfl OPrAHM3AUt4R fl0 CTAHAAPTH3AUHHRGANSATlON INTERNATIONALE DE NORMALlSATlON Plastics - Determination of stiffness in torsion of flexible materials - Part 1 : General method Plastiques - Dkterminatio
2、n de la rigiditk en torsion des plastiques souples - Partie I : Mt5thode g C W is the sum of the two weights, in newtons, used to apply the torque. A reading shall be taken by releasing the torque pulley and noting the angle of deflection, 19, after an interval of 5 s. The pulley shall then be retur
3、ned to the zero position and, if ap- plicable, the procedure shall be repeated at successively higher temperatures. The value of B and the temperature shall be recorded for each reading. The testing shall be done in such a way that the angular deflec- tion value falls within the range from IO to 100
4、” (method A), or from 50 to E-0 (method B). I) IkPa = 1 kN/m2 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 21:55:53 MDTNo reproduction or networking permitted without licens
5、e from IHS -,-,- IS0 4!58/1-1985 (E) If the value of the angle of deflection does not fall within the range given above, the applied torque shall be varied in such a way as to produce a suitable reading, If this is found to be in- sufficient, a specimen of another thickness shall be taken for testin
6、g. NOTE - Results obtained for a given material by methods A and B may differ from each other. 7 Expression of results 7.1 The stiffness in torsion, expressed as the apparent tor- sional modulus of elasticity T, for each temperature is given, in megapascals, by the equation 917 L M T=- bd3 ,u 8 or,
7、in a modified form T=kf 917 L kc- bd3 p where L is the span, in millimetres; M is the applied torque, in newton millimetres; b is the average width of the specimen (the larger cross- sectional dimension), in millimetres; d is the average thickness of the specimen (the smaller cross-sectional dimensi
8、on), in millimetres; ,U is a value depending on the ratio b/d; the table gives the values for p for various ratios of b/d (intermediate values may be found by interpolation); t9 is the angle of deflection, in degrees; 917 is a dimensional constant, in angular degrees; k is a factor depending on spec
9、imen dimensions, in angular degrees per cubic millimetre. The modified equation is recommended for use when repeated tests of the same specimen are being made. 7.2 If testing has been done over a wide range of tempera- tures, plot for each specimen tested the logarithm of stiffness in torsion versus
10、 temperature. Table - Values for ,Y as a function of bld Ratio bid P Ratio bld P I,20 z64 2,50 3,99 I,30 2,82 2,75 4,ll I,40 238 3m 4.21 130 3,13 3,50 4,37 1BJ 3,26 4.00 4.49 1,70 3,37 4,50 4.58 1,80 3148 5.00 4,66 19 3,57 5.50 4,72 zoo 3.66 6.00 4,77 2,25 3,84 GO 4,81 NOTE - The p values in the tab
11、le are given by the equation p = 533 -,.,+(I - b) full details necessary for identification of the material, including name, stock or code number, date made, form, etc.; c) nominal dimensions of test specimen (span, width, thickness); d1 details of conditioning of test specimen prior to test; e) hea
12、t-transfer medium used; f) table of data and results (temperature, angular deflec- tion, stiffness in torsion); g) plot of the logarithm of the mean value of stiffness in torsion for both test specimens versus temperature (if a wide range of temperatures is used). Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 21:55:53 MDTNo reproduction or networking permitted without license from IHS -,-,-