1、 KSKSKSKS KSKSKSK KSKSKS KSKSK KSKS KSK KS KS B ISO 18431 2 2： KS B ISO 18431 2:2013 2013 5 13 http:/www.kats.go.krKS B ISO 18431 2:2013 : ( ) ( ) () () () ( ) : (http:/www.standard.go.kr) ： ：2008 10 17 ：2013 5 13 2013-0168 ： ： ( 02-509-7274) (http:/www.kats.go.kr). 10 5 , . KS B ISO 18431 2:2013 i
2、ii 1 1 2 1 3 .1 4 2 5 .2 5.1 .2 5.2 3 5.3 3 5.4 5 6 6 6.1 .6 6.2 .8 10 KS B ISO 18431 2:2013 ii 2004 1 ISO 18431 2, Mechanical vibration and shock Signal processing Part 2 ： Time domain windows for Fourier Transform analysis 2008 AMENDMENT 1： Statistical analysis method , . KS B ISO 18431 2:2013 2：
3、Mechanical vibration and shock Signal processing Part 2： Time domain windows for Fourier Transform analysis 1 . (Fourier) . (Hanning), (flat-top) (rectangular) . , - . 2 . . ( ) . KS B ISO 2041, , 3 . 3.1 (Discrete Fourier Transform) DFT - N =10/2se)(1)(NnNmninxfmX 4. . KS B ISO 18431 2:2013 2 3.2 (
4、Fast Fourier Transform) FFT (DFT) - (Cooley-Tukey, 1 ) - (Sande-Tukey) . 3.3 (time windows) ( ) (ensemble) 4 a(i) (flat-top) Be (equivalent noise bandwidth) fs (sampling) i m n N , w(n) W(m) x(n) X(n) x(nt) 5 5.1 : (hanning), (flat top) (rectangular). , . 1 (Highest sidelobe) dB (Sidelobe rolloff)dB
5、/decade (Noise bandwidth)No. of linesa (Maximum amplitude error) dB (Hanning) 31.5 60 1.50 1.4 (Flat-top) 93.0 0 3.77 0.01 (Rectangular) 13.3 20 1.00 3.9 a . KS B ISO 18431 2:2013 3 ( , ) , ( , ) . NfnwNnwNBNnNn s210102e)(1)(1=(1) 2 4 . 5.2 , . w(v) 1 cos(2n/N)(2) n 0, 1, N 1 N . 1 1 024 (fs) 1 024-
6、 . 5.3 , . w(n) 1 a1cos(2n/N) a2cos(4n/N) a3cos(6n/N) a4cos(8n/N) (3) n 0, 1, N 1 a1 1.932 617 19 a2 1.286 132 81 a3 0.387 695 31 a4 0.032 226 56 N . 2 1 024 (fs) 1 024- . KS B ISO 18431 2:2013 4 a) X Y , w(n) b) X (Hz) Y , W(m) 1 1 024 KS B ISO 18431 2:2013 5 a) X Y , w(n) b) X (Hz) Y , W(m) 2 1 02
7、4 5.4 . w(n) 1 (4) n 0, 1, N 1 N . 3 1 024 (fs) 1 024- . KS B ISO 18431 2:2013 6 a) X Y , w(n) b) X (Hz) Y , W(m) 3 1 024 6 6.1 4 2 1 024 (fs) 214 . , . KS B ISO 18431 2:2013 7 a) X Y , x(n) b) c) d) X (Hz) Y X(m) 4 214 KS B ISO 18431 2:2013 8 2 0 0.007 3 0.003 3 0.141 5 1 0.010 1 0.069 4 0.148 8 2
8、0.025 4 0.398 8 0.176 3 3 0.170 5 0.850 7 0.254 6 4 0.848 3 0.998 9 0.674 1 5 0.849 2 0.999 0 0.603 1 6 0.169 5 0.850 6 0.181 9 7 0.024 0 0.398 9 0.099 7 8 0.007 9 0.069 3 0.065 5 9 0.003 5 0.001 7 0.047 2 10 0.001 9 0.000 0 0.035 9 6.2 5 3 1 024 (fs) 4 . , 0 . 3 0 0.000 0 0.000 0 0.000 0 1 0.000 0
9、0.194 0 0.000 0 2 0.000 0 0.643 0 0.000 0 3 0.500 0 0.966 5 0.000 0 4 1.000 0 1.000 0 1.000 0 5 0.500 0 0.966 5 0.000 0 6 0.000 0 0.643 0 0.000 0 7 0.000 0 0.194 0 0.000 0 8 0.000 0 0.016 0 0.000 0 9 0.000 0 0.000 0 0.000 0 10 0.000 0 0.000 0 0.000 0 KS B ISO 18431 2:2013 9 a) X Y , x(n) b) c) d) X
10、(Hz) Y X(m) 5 4 KS B ISO 18431 2:2013 10 1 COOLEY, J.W. and TUKEY, J.W. An Algorithm for the Machine Computation of the Complex Fourier Series. Mathematics of Computation, 19, April 1965, pp. 297 301 2 HARRIS, F.J. On the Use of Windows for Harmonic Analysis with the Discrete Fourier Transform. Proc
11、eedings of the IEEE, 66, January 1978, pp. 51 83 3 RANDALL, R.B. Frequency Analysis. 3rd Ed., Bruel & Kjaer, Glostrup, Denmark, 1987 (ISBN 87 87355 07 8) 4 GADE, S. and HERLUFSEN, H. Use of Weighting Functions in DFT/FFT Analysis： Part I. Bruel and Kjaer, Technical Review, No. 3, 1987 (ISSN 007-2621
12、) 5 GADE, S. and HERLUFSEN, H. Use of Weighting Functions in DFT/FFT Analysis： Part II. Bruel and Kjaer, Technical Review, No. 4, 1987 (ISSN 007-2621) 2： 153787 1 145 3(16) (02)26240114 (02)26240148 http:/ Korean Agency for Technology and Standards http:/www.kats.go.kr KS B ISO 18431 2:2013KSKSKS SKSKS KSKS SKS KS SKS KSKS SKSKS KSKSKS Mechanical vibration and shock Signal processing Part 2： Time domain windows for Fourier Transform analysis ICS 17.160
