93 5 [19] 3 4 5.1 3 1/15 3 2kHz 1/2 85mm 500Hz 2/3
94 5 5.1: 1/3 3 3.5 20dB 1/3 0.315 500Hz 210mm 1/6 1/2 5.1 5.1.1 1 200Hz 1/3 500Hz 4 315Hz 500Hz?? 5.3 200Hz 170 250Hz 215 280Hz 315Hz 275 395Hz 500Hz 380 550Hz
5.1. 95 170 170 210 270 110 270 340 180 design frequency : 500Hz design frequency : 315Hz 5.2: -10-15 -20 normalized SPL [db] -25-30 -35-40 200Hz 250Hz 315Hz 500Hz Plane Barrier -45 125 250 500 1000 frequency [Hz] 5.3:
96 5 1/2 3 3.5 1/3 20dB 5.1 5m 250Hz 12.5dB 500Hz 16.2dB 2.37m 250Hz 8.4dB 500Hz 12.0dB 14dB 10dB 3.5 14dB 0.44 5.1.2 2 5.3 500Hz 315Hz 4.3 500Hz 315Hz 250Hz 200Hz 5.4 500Hz 315Hz 250Hz 1 200Hz 1/2 1 5.1.3 4.4 6 500Hz 6 1/5 250Hz
5.1. 97-10 -15 normalized SPL [db] -20-25 -30 315+500Hz 250+500Hz 200+500Hz plane barrier -35 125 250 500 1000 frequency [Hz] 5.4: 2 1/4 1/3 3/7 1/4 210Hz 1/3 160Hz 3/7 113Hz 5.5 5.6 1/5 1/4 1/3 500Hz 250Hz 1/3 3/2 3/7 4 0.315 1/6
98 5 1/3
5.1. 99 Design frequency change width 1/5 oct. Design frequency change width 1/4 oct. Design frequency change width 1/3 oct. Design frequency change width 3/7 oct. 5.5:
100 5-10 -15-20 normalized SPL [db] -25-30 -35 1/5 oct. 1/4 oct. 1/3 oct. 3/7 oct plane barrier -40 125 250 500 frequency [Hz] 5.6:
5.2. 101 5.2 [25] 1/3λ 1m 500mm[26] 500mm 5 5.7 200 500Hz 5.7:
102 5 5.2.1 5.8 1/1 L 1 (v) L 2 (v) L 3 (5.1) (5.3) [25] v (km/h) L n (200) (200km/h) 700 L 1 (200) = 108.5dB(A) L 2 (200) = 88dB(A) L 3 (200) = 97dB(A) 700 [27] [25] L 1 (v) = L 1 (200) + 30 log(v/200) (5.1) L 2 (v) = L 2 (200) + 60 log(v/200) (5.2) L 3 (v) = L 3 (200) + 60 log(v/200) (5.3) 5.9 5.11 2m 5m 5m 2.37m 210mm (Slit) 5.1 250Hz 500Hz 3.6dB 5.1: [db(a)] Barrier Shape Rolling Noise Aerodynamic Noise Bow Collector Noise Plane H=2m 73.8 82.3 88.1 Plane H=5m 64.1 62.1 74.6 with Slit 74.3 66.8 76.6 with 5Tubes 74.7 65.3 75.2
5.2. 103 2m 5m 250Hz 2000Hz
104 5 Bow Collector Noise Aerodynamic Noise 5,174 3,550 3,674 1,090 3,380 2,370 Rolling Noise 1,000 8,000 2,690 25,000 Receiver 5.8: A-Weighted Sound Pressure Level [db] 75 70 65 60 55 50 Plane Barrier H=2m Plane Barrier H=5m H=5m Slit barrier H=5m with 5 Tubes 45 63 125 250 500 1000 2000 4000 frequency [Hz] 5.9:
5.2. 105 80 75 A-Weighted Sound Pressure Level [db] 70 65 60 55 50 45 40 Plane Barrier H=2m Plane Barrier H=5m H=5m Slit barrier H=5m with 5 Tubes 63 125 250 500 1000 2000 4000 frequency [Hz] 5.10: 85 A-Weighted Sound Pressure Level [db] 80 75 70 65 60 Plane Barrier H=2m Plane Barrier H=5m H=5m Slit barrier H=5m with 5 Tubes 55 63 125 250 500 1000 2000 4000 frequency [Hz] 5.11:
106 5 5.2.2 2 1/10 2 27mm 32kg/m 3 48kg/m 3 2 6.3kHz 2 5.12 2-Dim Anechoic Chamber 1,340 1,000 500 1,200 Barrier Train 500 Source 269 500 Receiver 5.12: 48kHz 2 14 0.34 M 10 2 4 4.17 5.13 5.14
5.2. 107 200 500Hz 27.9dB 26.9dB 125Hz 3
108 5 40 35 Plane Barrier with 5Tubes 30 Insertion Loss [db] 25 20 15 10 5 0 125 250 500 frequency [Hz] 5.13: 50 45 Plane Barrier with 5Tubes 40 35 Insertion Loss [db] 30 25 20 15 10 5 0-5 125 250 500 frequency [Hz] 5.14:
5.3. 109 5.3 5.15 5.15 transformer Short circuit Barrier transformer 5.15: 2 5.16 60Hz 1.5m 1 L eq 1/3 5.16 FFT 1Hz
110 5 65 transformer noise 60 A-weighted sound pressure level [db] 55 50 45 40 35 30 63 125 250 500 1000 2000 4000 frequency [Hz] 5.16: 50 500Hz 5.17 5.16 FFT 60Hz 2 120Hz 240Hz 360Hz 5.17 1 FFT 120Hz 240Hz 360Hz 1 4.2.1 1/5 4.2.3 1/6
5.3. 111 60 55 transformer noise (FFT) 50 Relative SPL [db] 45 40 35 30 25 20 15 10 50 100 150 200 250 300 350 400 450 500 frequency [Hz] 5.17: FFT 1/4 1/6 CD-type 2 CD-type 120Hz CD-type 240 360Hz 1/4 90 1/4 [15] CD-type 1:3 120Hz (4.6) 1 1/54 500mm
112 5 905 472 189 157 236 236 157 189 231 236 334 935 708 236 500 283 567 354 1,587 283 567 708 2,003 Source 708 Source 500 Composition of straight sound tubes Composition of the tubes containing CD-type 5.18: 5.18 5.19 2.5m 15m 5m 5.20 CD-type 360Hz 5.17 5.20 50 500Hz 46.5dB 45.4dB CD-type 45.1dB
5.3. 113 Barrier Height = 5m GL Source Receiver 2.5m 15m 5.19: 30 25 Insertion Loss [db] 20 15 10 5 composition of straight sound tubes containing CD-type Plane Barrier 0 50 100 150 200 250 300 350 400 450 500 frequency [Hz] 5.20:
114 5