{"id":15972,"date":"2026-09-04T08:51:36","date_gmt":"2026-09-04T08:51:36","guid":{"rendered":"https:\/\/www.hndfcrane.com\/?post_type=posts&#038;p=15972"},"modified":"2026-09-04T08:51:39","modified_gmt":"2026-09-04T08:51:39","slug":"overhead-crane-reducer-noise-gear-eccentricity-analysis-and-solutions","status":"publish","type":"posts","link":"https:\/\/www.hndfcrane.com\/vi\/posts\/overhead-crane-reducer-noise-gear-eccentricity-analysis-and-solutions\/","title":{"rendered":"Ti\u1ebfng \u1ed3n t\u1eeb h\u1ed9p gi\u1ea3m t\u1ed1c c\u1ea7n c\u1ea9u tr\u00ean cao: Ph\u00e2n t\u00edch \u0111\u1ed9 l\u1ec7ch t\u00e2m b\u00e1nh r\u0103ng v\u00e0 c\u00e1c gi\u1ea3i ph\u00e1p"},"content":{"rendered":"<div class=\"wp-block-rank-math-toc-block\" id=\"rank-math-toc\"><p>M\u1ee5c l\u1ee5c<\/p><nav><ul><li><a href=\"#1-gear-excitation-analysis-under-eccentricity-error\">1. Ph\u00e2n t\u00edch k\u00edch th\u00edch b\u00e1nh r\u0103ng d\u01b0\u1edbi t\u00e1c \u0111\u1ed9ng c\u1ee7a sai s\u1ed1 l\u1ec7ch t\u00e2m<\/a><ul><li><a href=\"#1-1-gear-pair-model\">1.1 M\u00f4 h\u00ecnh c\u1eb7p b\u00e1nh r\u0103ng<\/a><\/li><\/ul><\/li><li><a href=\"#2-numerical-calculation-of-gear-excitation-in-overhead-crane-reducer-noise\">2. T\u00ednh to\u00e1n s\u1ed1 h\u1ecdc v\u1ec1 s\u1ef1 k\u00edch th\u00edch b\u00e1nh r\u0103ng trong ti\u1ebfng \u1ed3n c\u1ee7a b\u1ed9 gi\u1ea3m t\u1ed1c c\u1ea7n c\u1ea9u tr\u00ean cao<\/a><ul><li><a href=\"#2-1-vibration-differential-equation\">2.1 Ph\u01b0\u01a1ng tr\u00ecnh vi ph\u00e2n dao \u0111\u1ed9ng<\/a><\/li><li><a href=\"#2-2-vibration-analysis-results\">2.2 K\u1ebft qu\u1ea3 ph\u00e2n t\u00edch rung \u0111\u1ed9ng<\/a><\/li><\/ul><\/li><li><a href=\"#3-radiated-noise-prediction-for-bogie-axle-bridge\">3. D\u1ef1 \u0111o\u00e1n ti\u1ebfng \u1ed3n b\u1ee9c x\u1ea1 cho c\u1ea7u tr\u1ee5c b\u00e1nh xe<\/a><ul><li><a href=\"#3-1-acoustic-model\">3.1 M\u00f4 h\u00ecnh \u00e2m thanh<\/a><\/li><li><a href=\"#3-2-measures-to-reduce-abnormal-noise\">3.2 C\u00e1c bi\u1ec7n ph\u00e1p gi\u1ea3m ti\u1ebfng \u1ed3n b\u1ea5t th\u01b0\u1eddng<\/a><\/li><\/ul><\/li><li><a href=\"#4-conclusion\">4. K\u1ebft lu\u1eadn<\/a><\/li><\/ul><\/nav><\/div>\n\n\n\n<p>Ti\u1ebfng \u1ed3n t\u1eeb b\u1ed9 gi\u1ea3m t\u1ed1c c\u1ea7n c\u1ea9u tr\u00ean cao c\u00f3 th\u1ec3 x\u1ea3y ra trong qu\u00e1 tr\u00ecnh n\u00e2ng h\u1ea1 v\u00e0 v\u1eadn chuy\u1ec3n v\u1eadt li\u1ec7u trong x\u01b0\u1edfng, \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn ho\u1ea1t \u0111\u1ed9ng b\u00ecnh th\u01b0\u1eddng c\u1ee7a c\u1ea7n c\u1ea9u. B\u00e0i vi\u1ebft n\u00e0y ph\u00e2n t\u00edch ti\u1ebfng \u1ed3n b\u1ea5t th\u01b0\u1eddng t\u1eeb g\u00f3c \u0111\u1ed9 sai s\u1ed1 l\u1ec7ch t\u00e2m c\u1ee7a c\u1eb7p b\u00e1nh r\u0103ng. D\u1ef1a tr\u00ean k\u1ebft qu\u1ea3 t\u00ednh to\u00e1n ti\u1ebfng \u1ed3n c\u1ea5u tr\u00fac t\u1eeb ph\u00e2n t\u00edch m\u00f4 ph\u1ecfng, b\u00e0i vi\u1ebft c\u0169ng \u0111\u01b0a ra c\u00e1c gi\u1ea3i ph\u00e1p t\u01b0\u01a1ng \u1ee9ng l\u00e0m t\u00e0i li\u1ec7u tham kh\u1ea3o \u0111\u1ec3 c\u1ea3i thi\u1ec7n. <a href=\"https:\/\/www.hndfcrane.com\/vi\/overhead-cranes\/\">c\u1ea7n c\u1ea9u tr\u00ean cao<\/a> hi\u1ec7u su\u1ea5t ho\u1ea1t \u0111\u1ed9ng.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1536\" height=\"1024\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Overhead-Crane-Reducer-Noise.png\" alt=\"\" class=\"wp-image-15994\"\/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"1-gear-excitation-analysis-under-eccentricity-error\">1. Ph\u00e2n t\u00edch k\u00edch th\u00edch b\u00e1nh r\u0103ng d\u01b0\u1edbi t\u00e1c \u0111\u1ed9ng c\u1ee7a sai s\u1ed1 l\u1ec7ch t\u00e2m<\/h2>\n\n\n\n<p>C\u1ea7n c\u1ea9u tr\u00ean cao \u0111\u01b0\u1ee3c ph\u00e2n t\u00edch trong b\u00e0i vi\u1ebft n\u00e0y l\u00e0 model LD10 t-28,5 m, \u0111\u01b0\u1ee3c trang b\u1ecb \u0111\u1ed9ng c\u01a1 kh\u00f4ng \u0111\u1ed3ng b\u1ed9 ba pha 13 kW. B\u1ed9 gi\u1ea3m t\u1ed1c s\u1eed d\u1ee5ng h\u1ec7 truy\u1ec1n \u0111\u1ed9ng b\u00e1nh r\u0103ng xo\u1eafn tr\u1ee5c song song b\u1ed1n c\u1ea5p. Khi x\u00e9t \u0111\u1ebfn sai s\u1ed1 l\u1ec7ch t\u00e2m, ph\u00e2n t\u00edch b\u1eaft \u0111\u1ea7u t\u1eeb m\u1ed9t c\u1eb7p b\u00e1nh r\u0103ng \u0111\u01a1n v\u00e0 chi\u1ec1u d\u00e0i \u0111\u01b0\u1eddng \u0103n kh\u1edbp c\u1ee7a n\u00f3.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"1-1-gear-pair-model\">1.1 M\u00f4 h\u00ecnh c\u1eb7p b\u00e1nh r\u0103ng<\/h3>\n\n\n\n<p>Khi x\u00e9t \u0111\u1ebfn \u0111\u1ed9 l\u1ec7ch t\u00e2m c\u1ee7a b\u00e1nh r\u0103ng, \u0111\u1ed9 l\u1ec7ch t\u00e2m c\u1ee7a b\u00e1nh r\u0103ng d\u1eabn \u0111\u1ed9ng v\u00e0 b\u00e1nh r\u0103ng b\u1ecb d\u1eabn \u0111\u1ed9ng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng l\u00e0m \u0111i\u1ec3m xu\u1ea5t ph\u00e1t. D\u1ef1a tr\u00ean s\u1ed1 r\u0103ng v\u00e0 t\u1ed1c \u0111\u1ed9 quay c\u1ee7a b\u00e1nh r\u0103ng d\u1eabn \u0111\u1ed9ng \u0111\u00e3 bi\u1ebft, c\u00f3 th\u1ec3 thu \u0111\u01b0\u1ee3c \u0111\u01b0\u1eddng cong \u0111\u1eb7c t\u00ednh th\u1eddi gian-t\u1ea7n s\u1ed1 c\u1ee7a t\u1ed1c \u0111\u1ed9 quay b\u00e1nh r\u0103ng b\u1ecb d\u1eabn \u0111\u1ed9ng v\u00e0 so s\u00e1nh v\u1edbi k\u1ebft qu\u1ea3 khi gi\u1ea3 \u0111\u1ecbnh kh\u00f4ng c\u00f3 \u0111\u1ed9 l\u1ec7ch t\u00e2m. M\u00f4 h\u00ecnh c\u1eb7p b\u00e1nh r\u0103ng l\u1ec7ch t\u00e2m \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n trong H\u00ecnh 1.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1385\" height=\"1136\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Eccentric-gear-pair-model.png\" alt=\"\" class=\"wp-image-15991\"\/><figcaption class=\"wp-element-caption\">H\u00ecnh 1. M\u00f4 h\u00ecnh c\u1eb7p b\u00e1nh r\u0103ng l\u1ec7ch t\u00e2m.<\/figcaption><\/figure>\n\n\n\n<p><code>O1<\/code> V\u00e0 <code>O2<\/code> l\u00e0 c\u00e1c t\u00e2m h\u00ecnh h\u1ecdc c\u1ee7a c\u1eb7p b\u00e1nh r\u0103ng trong \u0111i\u1ec1u ki\u1ec7n kh\u00f4ng c\u00f3 \u0111\u1ed9 l\u1ec7ch t\u00e2m. Sau khi t\u00ednh \u0111\u1ebfn \u0111\u1ed9 l\u1ec7ch t\u00e2m. <code>E1<\/code> V\u00e0 <code>E2<\/code> x\u1ea3y ra, t\u00e2m h\u00ecnh h\u1ecdc c\u1ee7a b\u00e1nh r\u0103ng tr\u1edf th\u00e0nh <code>O11<\/code> V\u00e0 <code>O22<\/code>C\u00f3 th\u1ec3 th\u1ea5y r\u1eb1ng, b\u1ea5t k\u1ec3 gi\u00e1 tr\u1ecb \u0111\u1ed9 l\u1ec7ch t\u00e2m l\u00e0 bao nhi\u00eau, \u0111\u01b0\u1eddng l\u01b0\u1edbi \u0111\u01b0\u1ee3c t\u1ea1o th\u00e0nh b\u1eb1ng c\u00e1ch n\u1ed1i c\u00e1c \u0111i\u1ec3m ti\u1ebfp tuy\u1ebfn. <code>T1(xT1, yT1)<\/code> V\u00e0 <code>T2(xT2, yT2)<\/code> lu\u00f4n c\u00f3 m\u1ed9t \u0111i\u1ec3m giao nhau n\u0103ng \u0111\u1ed9ng <code>M(xM, yM)<\/code> v\u1edbi \u0111\u01b0\u1eddng th\u1eb3ng n\u1ed1i c\u00e1c t\u00e2m h\u00ecnh h\u1ecdc c\u1ee7a b\u00e1nh r\u0103ng.<\/p>\n\n\n\n<p>X\u00e9t \u0111\u1ebfn \u0111\u1ed9 l\u1ec7ch, \u0111\u01b0\u1eddng \u0103n kh\u1edbp c\u1ee7a c\u1eb7p b\u00e1nh r\u0103ng c\u00f3 \u0111\u1eb7c t\u00ednh thay \u0111\u1ed5i theo th\u1eddi gian. Ph\u01b0\u01a1ng tr\u00ecnh c\u1ee7a n\u00f3 c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n nh\u01b0 sau:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1005\" height=\"192\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Gear-Pair-Meshing-Line-Equation-watermarked.png\" alt=\"\" class=\"wp-image-16002\"\/><\/figure>\n\n\n\n<p>Khi g\u1ed1c t\u1ecda \u0111\u1ed9 \u0111\u01b0\u1ee3c \u0111\u1eb7t t\u1ea1i \u0111i\u1ec3m <code>O11<\/code>, t\u1ecda \u0111\u1ed9 ngang \u0111\u1ed9ng c\u1ee7a \u0111i\u1ec3m <code>M<\/code> c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c di\u1ec5n \u0111\u1ea1t nh\u01b0 sau:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"977\" height=\"198\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Dynamic-Intersection-Point-Coordinate-Equation-watermarked.png\" alt=\"\" class=\"wp-image-16003\"\/><\/figure>\n\n\n\n<p>T\u1ef7 s\u1ed1 truy\u1ec1n t\u1ee9c th\u1eddi c\u1ee7a c\u1eb7p b\u00e1nh r\u0103ng l\u00e0:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"924\" height=\"204\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Instantaneous-Gear-Transmission-Ratio-Equation-watermarked.png\" alt=\"\" class=\"wp-image-16004\"\/><\/figure>\n\n\n\n<p>Trong t\u00ednh to\u00e1n th\u1ef1c t\u1ebf, \u0111i\u1ec3m giao nhau \u0111\u1ed9ng <code>M<\/code> c\u00f3 m\u1ed1i quan h\u1ec7 nh\u1ea5t \u0111\u1ecbnh v\u1edbi \u0111\u01b0\u1eddng \u0103n kh\u1edbp, g\u00f3c gi\u1eefa h\u01b0\u1edbng chuy\u1ec3n \u0111\u1ed9ng v\u00e0 t\u1ed1c \u0111\u1ed9 \u0111\u01b0\u1eddng \u0103n kh\u1edbp t\u1ee9c th\u1eddi c\u1ee7a b\u00e1nh r\u0103ng. Sau khi x\u00e1c \u0111\u1ecbnh ph\u1ea1m vi l\u1ec7ch t\u00e2m v\u00e0 v\u1eadn t\u1ed1c g\u00f3c \u0111\u1ea7u v\u00e0o, c\u00e1c c\u00f4ng th\u1ee9c (1) \u0111\u1ebfn (3) c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 thu \u0111\u01b0\u1ee3c v\u1eadn t\u1ed1c g\u00f3c c\u1ee7a b\u00e1nh r\u0103ng b\u1ecb d\u1eabn \u0111\u1ed9ng v\u00e0 t\u00ednh to\u00e1n th\u00eam k\u00edch th\u00edch \u0111\u1ed9ng c\u1ee7a c\u1eb7p b\u00e1nh r\u0103ng d\u01b0\u1edbi l\u1ed7i l\u1ec7ch t\u00e2m.<\/p>\n\n\n\n<p>Trong s\u1ea3n xu\u1ea5t th\u1ef1c t\u1ebf, s\u1ef1 kh\u00e1c th\u01b0\u1eddng <code>E1<\/code> V\u00e0 <code>E2<\/code> C\u00f3 th\u1ec3 coi ch\u00fang g\u1ea7n nh\u01b0 gi\u1ed1ng nhau. V\u1edbi \u0111\u1ed9 l\u1ec7ch t\u00e2m c\u1ee7a c\u1eb7p b\u00e1nh r\u0103ng xo\u1eafn l\u00e0 20 \u03bcm theo c\u1ea5p \u0111\u1ed9 ch\u00ednh x\u00e1c \u0111\u00e3 bi\u1ebft, \u0111\u01b0\u1eddng cong \u0111\u1eb7c t\u00ednh th\u1eddi gian-t\u1ea7n s\u1ed1 \u0111\u01b0\u1ee3c t\u00ednh to\u00e1n c\u1ee7a b\u00e1nh r\u0103ng b\u1ecb d\u1eabn \u0111\u1ed9ng \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n trong H\u00ecnh 2.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1033\" height=\"1523\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Time-frequency-curve-of-driven-gear-angular-velocity.png\" alt=\"\" class=\"wp-image-15989\"\/><figcaption class=\"wp-element-caption\">H\u00ecnh 2. \u0110\u01b0\u1eddng cong th\u1eddi gian-t\u1ea7n s\u1ed1 c\u1ee7a v\u1eadn t\u1ed1c g\u00f3c b\u00e1nh r\u0103ng d\u1eabn \u0111\u1ed9ng: (a) v\u1eadn t\u1ed1c g\u00f3c trong mi\u1ec1n th\u1eddi gian; (b) v\u1eadn t\u1ed1c g\u00f3c trong mi\u1ec1n t\u1ea7n s\u1ed1<\/figcaption><\/figure>\n\n\n\n<p>Khi gi\u1ea3 \u0111\u1ecbnh kh\u00f4ng c\u00f3 sai s\u1ed1 l\u1ec7ch t\u00e2m, v\u1eadn t\u1ed1c g\u00f3c c\u1ee7a b\u00e1nh r\u0103ng d\u1eabn \u0111\u1ed9ng \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng \u0111\u01b0\u1eddng th\u1eb3ng m\u00e0u h\u1ed3ng trong H\u00ecnh 2a. Khi c\u00f3 sai s\u1ed1 l\u1ec7ch t\u00e2m, v\u1eadn t\u1ed1c g\u00f3c c\u1ee7a b\u00e1nh r\u0103ng d\u1eabn \u0111\u1ed9ng th\u1ec3 hi\u1ec7n s\u1ef1 dao \u0111\u1ed9ng r\u00f5 r\u00e0ng v\u00e0 \u0111\u1ec1u \u0111\u1eb7n, t\u1eadp trung trong kho\u1ea3ng 40,5-41,5 rad\/s. K\u1ebft qu\u1ea3 trong mi\u1ec1n t\u1ea7n s\u1ed1 sau khi bi\u1ebfn \u0111\u1ed5i Fourier ph\u1ea3n \u00e1nh t\u1ea7n s\u1ed1 quay c\u1ee7a tr\u1ee5c \u0111\u1ea7u v\u00e0o l\u00e0 25 Hz v\u00e0 t\u1ea7n s\u1ed1 quay c\u1ee7a b\u00e1nh r\u0103ng d\u1eabn \u0111\u1ed9ng l\u00e0 6,5 Hz. \u0110i\u1ec1u n\u00e0y cho th\u1ea5y s\u1ef1 dao \u0111\u1ed9ng l\u1ec7ch t\u00e2m c\u1ee7a c\u1eb7p b\u00e1nh r\u0103ng \u0111\u1ea7u v\u00e0o c\u00f3 th\u1ec3 ti\u1ebfp t\u1ee5c truy\u1ec1n qua h\u1ec7 th\u1ed1ng b\u00e1nh r\u0103ng v\u00e0 b\u1ee9c x\u1ea1 ra b\u00ean ngo\u00e0i h\u1ed9p s\u1ed1.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"2-numerical-calculation-of-gear-excitation-in-overhead-crane-reducer-noise\">2. T\u00ednh to\u00e1n s\u1ed1 h\u1ecdc v\u1ec1 s\u1ef1 k\u00edch th\u00edch b\u00e1nh r\u0103ng trong ti\u1ebfng \u1ed3n c\u1ee7a b\u1ed9 gi\u1ea3m t\u1ed1c c\u1ea7n c\u1ea9u tr\u00ean cao<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"2-1-vibration-differential-equation\">2.1 Ph\u01b0\u01a1ng tr\u00ecnh vi ph\u00e2n dao \u0111\u1ed9ng<\/h3>\n\n\n\n<p>Ph\u01b0\u01a1ng tr\u00ecnh vi ph\u00e2n dao \u0111\u1ed9ng c\u1ee7a h\u1ec7 b\u00e1nh r\u0103ng trong h\u1ed9p gi\u1ea3m t\u1ed1c c\u1ea7n c\u1ea9u tr\u00ean cao l\u00e0 c\u01a1 s\u1edf quan tr\u1ecdng \u0111\u1ec3 nghi\u00ean c\u1ee9u c\u00e1c \u0111\u1eb7c t\u00ednh \u0111\u1ed9ng h\u1ecdc c\u1ee7a n\u00f3. B\u1eb1ng c\u00e1ch gi\u1ea3m b\u1eadc v\u00e0 t\u00ednh to\u00e1n l\u1ef1c \u0103n kh\u1edbp \u0111\u1ed9ng c\u1ee7a b\u00e1nh r\u0103ng, c\u00e1c \u0111\u1eb7c t\u00ednh dao \u0111\u1ed9ng nh\u01b0 c\u01b0\u1eddng \u0111\u1ed9 dao \u0111\u1ed9ng v\u00e0 ti\u1ebfng \u1ed3n k\u1ebft c\u1ea5u c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c m\u00f4 ph\u1ecfng b\u1eb1ng s\u1ed1. Ph\u01b0\u01a1ng tr\u00ecnh vi ph\u00e2n b\u1eadc hai c\u1ea7n thi\u1ebft l\u00e0:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"965\" height=\"135\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Gear-System-Vibration-Differential-Equation-watermarked.png\" alt=\"\" class=\"wp-image-16005\"\/><\/figure>\n\n\n\n<p>Ph\u01b0\u01a1ng tr\u00ecnh th\u1eddi gian c\u1ee7a t\u1ecda \u0111\u1ed9 \u0111\u1ed9ng <code>M<\/code> \u0111\u01b0\u1ee3c thay th\u1ebf v\u00e0o <code>\u03b8<\/code>Nguy\u00ean l\u00fd gi\u1ea3m b\u1eadc Runge-Kutta \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 gi\u1ea3i b\u00e0i to\u00e1n l\u1ef1c \u0103n kh\u1edbp \u0111\u1ed9ng c\u1ee7a c\u1eb7p b\u00e1nh r\u0103ng t\u1ed1c \u0111\u1ed9 cao. H\u00ecnh 3 th\u1ec3 hi\u1ec7n k\u1ebft qu\u1ea3 t\u00ednh to\u00e1n l\u1ef1c \u0103n kh\u1edbp \u1edf giai \u0111o\u1ea1n \u0111\u1ea7u v\u00e0o v\u00e0 giai \u0111o\u1ea1n \u0111\u1ea7u ra cu\u1ed1i c\u00f9ng.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1022\" height=\"1538\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Frequency-domain-of-dynamic-meshing-force.png\" alt=\"\" class=\"wp-image-15978\" srcset=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Frequency-domain-of-dynamic-meshing-force.png 1022w, https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Frequency-domain-of-dynamic-meshing-force-1021x1536.png 1021w\" sizes=\"(max-width: 1022px) 100vw, 1022px\" \/><figcaption class=\"wp-element-caption\">H\u00ecnh 3. Mi\u1ec1n t\u1ea7n s\u1ed1 c\u1ee7a l\u1ef1c \u0103n kh\u1edbp \u0111\u1ed9ng: (a) giai \u0111o\u1ea1n \u0111\u1ea7u v\u00e0o; (b) giai \u0111o\u1ea1n \u0111\u1ea7u ra<\/figcaption><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"2-2-vibration-analysis-results\">2.2 K\u1ebft qu\u1ea3 ph\u00e2n t\u00edch rung \u0111\u1ed9ng<\/h3>\n\n\n\n<p>H\u00ecnh 4 th\u1ec3 hi\u1ec7n c\u1ea5u tr\u00fac c\u1ee7a b\u1ed9 gi\u1ea3m t\u1ed1c. V\u1ecb tr\u00ed \u0111\u1eb7t \u1ed5 tr\u1ee5c \u1edf \u0111\u1ea7u v\u00e0o v\u00e0 \u0111\u1ea7u ra \u0111\u01b0\u1ee3c ch\u1ecdn \u0111\u1ec3 t\u00ednh to\u00e1n, v\u00e0 thu \u0111\u01b0\u1ee3c c\u00e1c \u0111\u01b0\u1eddng cong \u0111\u1eb7c t\u00ednh dao \u0111\u1ed9ng trong mi\u1ec1n t\u1ea7n s\u1ed1 v\u1edbi sai s\u1ed1 l\u1ec7ch t\u00e2m 20 \u03bcm.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"900\" height=\"600\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Structure-of-an-overhead-crane-reducer.jpg\" alt=\"\" class=\"wp-image-15976\"\/><figcaption class=\"wp-element-caption\">H\u00ecnh 4. C\u1ea5u tr\u00fac c\u1ee7a b\u1ed9 gi\u1ea3m t\u1ed1c c\u1ea7n c\u1ea9u tr\u00ean cao.<\/figcaption><\/figure>\n\n\n\n<p>Nh\u01b0 th\u1ec3 hi\u1ec7n trong H\u00ecnh 5, sau khi \u0111\u00e3 xem x\u00e9t sai s\u1ed1 l\u1ec7ch t\u00e2m, t\u1ea7n s\u1ed1 quay c\u1ee7a tr\u1ee5c \u0111\u1ea7u v\u00e0o l\u00e0 25 Hz \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn c\u00e1c c\u1eb7p b\u00e1nh r\u0103ng kh\u00e1c nhau \u1edf c\u00e1c giai \u0111o\u1ea1n kh\u00e1c nhau, \u0111\u1eb7c bi\u1ec7t l\u00e0 trong \u0111\u01b0\u1eddng cong d\u1ecbch chuy\u1ec3n. Vi\u1ec7c t\u00ednh to\u00e1n ti\u1ebfng \u1ed3n d\u1ef1a tr\u00ean k\u1ebft qu\u1ea3 rung \u0111\u1ed9ng sau \u0111\u00f3 c\u00f3 th\u1ec3 cho th\u1ea5y \u1ea3nh h\u01b0\u1edfng c\u1ee7a sai s\u1ed1 l\u1ec7ch t\u00e2m \u0111\u1ebfn ti\u1ebfng \u1ed3n b\u1ea5t th\u01b0\u1eddng c\u1ee7a h\u1ed9p gi\u1ea3m t\u1ed1c.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1006\" height=\"1564\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Vibration-response-analysis-results.png\" alt=\"\" class=\"wp-image-15979\" srcset=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Vibration-response-analysis-results.png 1006w, https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Vibration-response-analysis-results-988x1536.png 988w\" sizes=\"(max-width: 1006px) 100vw, 1006px\" \/><figcaption class=\"wp-element-caption\">H\u00ecnh 5 K\u1ebft qu\u1ea3 ph\u00e2n t\u00edch \u0111\u00e1p \u1ee9ng rung \u0111\u1ed9ng: (a) gia t\u1ed1c; (b) \u0111\u1ed9 d\u1ecbch chuy\u1ec3n rung \u0111\u1ed9ng<\/figcaption><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"3-radiated-noise-prediction-for-bogie-axle-bridge\">3. D\u1ef1 \u0111o\u00e1n ti\u1ebfng \u1ed3n b\u1ee9c x\u1ea1 cho c\u1ea7u tr\u1ee5c b\u00e1nh xe<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"3-1-acoustic-model\">3.1 M\u00f4 h\u00ecnh \u00e2m thanh<\/h3>\n\n\n\n<p>Theo c\u00e1c t\u00e0i li\u1ec7u tham kh\u1ea3o \u0111\u00e3 d\u1eabn, \u00e2m h\u1ecdc thu\u1ed9c l\u0129nh v\u1ef1c nghi\u00ean c\u1ee9u ch\u1ea5t l\u1ecfng. Do \u0111\u00f3, ph\u01b0\u01a1ng tr\u00ecnh s\u00f3ng \u00e2m c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c nghi\u00ean c\u1ee9u t\u1eeb ph\u01b0\u01a1ng tr\u00ecnh li\u00ean t\u1ee5c c\u1ee7a ch\u1ea5t l\u1ecfng. V\u1ec1 tr\u1ea1ng th\u00e1i m\u00f4i tr\u01b0\u1eddng, n\u00f3 c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n nh\u01b0 sau:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1224\" height=\"500\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Acoustic-Wave-Governing-Equations-watermarked.png\" alt=\"\" class=\"wp-image-16006\"\/><\/figure>\n\n\n\n<p>Trong c\u00f4ng th\u1ee9c, <code>\u03c1<\/code>, <code>v<\/code>, <code>P<\/code>, V\u00e0 <code>S<\/code> l\u00e0 m\u1eadt \u0111\u1ed9, v\u1eadn t\u1ed1c, \u00e1p su\u1ea5t \u00e2m thanh v\u00e0 entropy c\u1ee7a kh\u00f4ng kh\u00ed, trong khi <code>f<\/code> V\u00e0 <code>q<\/code> l\u00e0 c\u00e1c ngu\u1ed3n k\u00edch th\u00edch b\u00ean ngo\u00e0i c\u1ee7a m\u00f4i tr\u01b0\u1eddng kh\u00f4ng kh\u00ed.<\/p>\n\n\n\n<p>D\u1ef1a tr\u00ean ph\u1ea3n \u1ee9ng rung \u0111\u1ed9ng c\u1ee7a b\u1ed9 gi\u1ea3m t\u1ed1c c\u1ea7n c\u1ea9u tr\u00ean cao, k\u1ebft qu\u1ea3 t\u00ednh to\u00e1n gia t\u1ed1c \u0111\u01b0\u1ee3c x\u1eed l\u00fd b\u1eb1ng ph\u00e9p bi\u1ebfn \u0111\u1ed5i Fourier v\u00e0 x\u1eed l\u00fd m\u1ed9t ph\u1ea7n ba qu\u00e3ng t\u00e1m. K\u1ebft qu\u1ea3 t\u00ednh to\u00e1n ti\u1ebfng \u1ed3n k\u1ebft c\u1ea5u c\u1ee7a \u1ed5 \u0111\u1ee1 c\u1ea5p t\u1ed1c cao c\u1ee7a b\u1ed9 gi\u1ea3m t\u1ed1c \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n trong H\u00ecnh 6.<\/p>\n\n\n\n<p>Khi x\u00e9t \u0111\u1ebfn sai s\u1ed1 l\u1ec7ch t\u00e2m, ti\u1ebfng \u1ed3n c\u1ea5u tr\u00fac c\u1ee7a b\u1ed9 gi\u1ea3m t\u1ed1c t\u0103ng r\u00f5 r\u1ec7t h\u01a1n \u1edf d\u1ea3i t\u1ea7n s\u1ed1 th\u1ea5p t\u1eeb 0-100 Hz. Theo l\u00fd thuy\u1ebft \u00e2m h\u1ecdc, ch\u00eanh l\u1ec7ch 6 dB t\u01b0\u01a1ng \u1ee9ng v\u1edbi m\u1ee9c n\u0103ng l\u01b0\u1ee3ng g\u1ea5p m\u1ed9t l\u1ea7n. Trong H\u00ecnh 6, s\u1ef1 kh\u00e1c bi\u1ec7t v\u1ec1 ti\u1ebfng \u1ed3n \u1edf m\u1ed9t s\u1ed1 d\u1ea3i t\u1ea7n s\u1ed1 \u0111\u1ea1t kho\u1ea3ng ba l\u1ea7n, cho th\u1ea5y sai s\u1ed1 l\u1ec7ch t\u00e2m c\u00f3 \u1ea3nh h\u01b0\u1edfng l\u1edbn \u0111\u1ebfn dao \u0111\u1ed9ng t\u1ea7n s\u1ed1 th\u1ea5p c\u1ee7a b\u1ed9 gi\u1ea3m t\u1ed1c. C\u00e1c \u0111\u1ec9nh r\u00f5 r\u00e0ng c\u0169ng xu\u1ea5t hi\u1ec7n \u1edf 500 Hz v\u00e0 1.000 Hz, do t\u1ea7n s\u1ed1 \u0103n kh\u1edbp b\u00e1nh r\u0103ng c\u1ee7a t\u1ea7ng \u0111\u1ea7u v\u00e0o g\u00e2y ra.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1588\" height=\"990\" src=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Structural-noise-of-the-reducer.png\" alt=\"\" class=\"wp-image-15980\" srcset=\"https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Structural-noise-of-the-reducer.png 1588w, https:\/\/www.hndfcrane.com\/wp-content\/uploads\/2026\/09\/Structural-noise-of-the-reducer-1536x958.png 1536w\" sizes=\"(max-width: 1588px) 100vw, 1588px\" \/><figcaption class=\"wp-element-caption\">H\u00ecnh 6. Ti\u1ebfng \u1ed3n c\u1ea5u tr\u00fac c\u1ee7a b\u1ed9 gi\u1ea3m t\u1ed1c.<\/figcaption><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"3-2-measures-to-reduce-abnormal-noise\">3.2 C\u00e1c bi\u1ec7n ph\u00e1p gi\u1ea3m ti\u1ebfng \u1ed3n b\u1ea5t th\u01b0\u1eddng<\/h3>\n\n\n\n<p>\u0110\u1ed9 l\u1ec7ch t\u00e2m 20 \u03bcm \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong t\u00ednh to\u00e1n \u0111\u01b0\u1ee3c l\u1ef1a ch\u1ecdn d\u1ef1a tr\u00ean c\u1ea5p \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ee7a b\u1ed9 truy\u1ec1n \u0111\u1ed9ng b\u00e1nh r\u0103ng. Trong ho\u1ea1t \u0111\u1ed9ng th\u1ef1c t\u1ebf, sai s\u1ed1 l\u1ec7ch t\u00e2m l\u1edbn h\u01a1n c\u00f3 th\u1ec3 t\u1ed3n t\u1ea1i v\u00e0 c\u00f3 th\u1ec3 \u1ea3nh h\u01b0\u1edfng \u0111\u00e1ng k\u1ec3 \u0111\u1ebfn vi\u1ec7c gi\u1ea3m rung v\u00e0 ti\u1ebfng \u1ed3n c\u1ee7a h\u1ed9p gi\u1ea3m t\u1ed1c. D\u1ef1a tr\u00ean ph\u00e2n t\u00edch v\u00e0 k\u1ebft lu\u1eadn trong b\u00e0i vi\u1ebft n\u00e0y, ti\u1ebfng \u1ed3n b\u1ea5t th\u01b0\u1eddng c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c gi\u1ea3m thi\u1ec3u t\u1eeb c\u00e1c kh\u00eda c\u1ea1nh sau:<\/p>\n\n\n\n<p>1. C\u1ea3i thi\u1ec7n vi\u1ec7c l\u1ef1a ch\u1ecdn c\u1ea5p \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ee7a b\u1ed9 truy\u1ec1n \u0111\u1ed9ng b\u00e1nh r\u0103ng. Nhi\u1ec1u c\u1ea7n c\u1ea9u tr\u00ean cao s\u1eed d\u1ee5ng b\u00e1nh r\u0103ng xo\u1eafn c\u1ea5p 8. C\u00e1c b\u1ed9 gi\u1ea3m t\u1ed1c c\u1ea7n c\u1ea9u th\u00f4ng th\u01b0\u1eddng kh\u00f4ng t\u00ednh \u0111\u1ebfn vi\u1ec7c gia c\u00f4ng ch\u00ednh x\u00e1c ti\u1ebfp theo, do \u0111\u00f3 sai s\u1ed1 l\u1ec7ch t\u00e2m c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn ti\u1ebfng \u1ed3n ph\u00e1t ra l\u1edbn h\u01a1n. N\u1ebfu xem x\u00e9t vi\u1ec7c t\u00f4i luy\u1ec7n v\u00e0 m\u00e0i b\u00e1nh r\u0103ng, \u0111\u00e1nh b\u00f3ng b\u1ec1 m\u1eb7t r\u0103ng ho\u1eb7c c\u00e1c ph\u01b0\u01a1ng ph\u00e1p x\u1eed l\u00fd t\u01b0\u01a1ng t\u1ef1 \u1edf giai \u0111o\u1ea1n ho\u00e0n thi\u1ec7n cu\u1ed1i c\u00f9ng, \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ea5p 7 ho\u1eb7c c\u1ea5p 6 c\u00f3 th\u1ec3 \u0111\u1ea1t \u0111\u01b0\u1ee3c. \u0110\u00e2y c\u00f3 th\u1ec3 l\u00e0 l\u1ef1a ch\u1ecdn t\u1ed1t h\u01a1n cho c\u00e1c x\u01b0\u1edfng c\u00f3 y\u00eau c\u1ea7u ki\u1ec3m so\u00e1t ti\u1ebfng \u1ed3n nghi\u00eam ng\u1eb7t h\u01a1n.<\/p>\n\n\n\n<p>2. T\u1ed1i \u01b0u h\u00f3a h\u1ec7 th\u1ed1ng truy\u1ec1n \u0111\u1ed9ng b\u00e1nh r\u0103ng. T\u1eeb g\u00f3c \u0111\u1ed9 h\u1ec7 th\u1ed1ng truy\u1ec1n \u0111\u1ed9ng, c\u1ea7n xem x\u00e9t c\u00e1c r\u00e0ng bu\u1ed9c nh\u01b0 \u0111\u1ed9 b\u1ec1n m\u1ecfi ti\u1ebfp x\u00fac b\u00e1nh r\u0103ng k\u00edn, t\u1ef7 s\u1ed1 truy\u1ec1n v\u00e0 h\u1ec7 s\u1ed1 chi\u1ec1u r\u1ed9ng m\u1eb7t b\u00edch. C\u00f3 th\u1ec3 s\u1eed d\u1ee5ng thu\u1eadt to\u00e1n di truy\u1ec1n \u0111\u1ec3 \u0111i\u1ec1u ch\u1ec9nh nh\u1eb9 m\u00f4-\u0111un b\u00e1nh r\u0103ng, chi\u1ec1u r\u1ed9ng r\u0103ng v\u00e0 s\u1ed1 r\u0103ng b\u00e1nh r\u0103ng d\u1eabn \u0111\u1ed9ng m\u00e0 kh\u00f4ng l\u00e0m thay \u0111\u1ed5i \u0111\u00e1ng k\u1ec3 c\u00e1c r\u00e0ng bu\u1ed9c n\u00e0y, sao cho t\u1ea7n s\u1ed1 truy\u1ec1n ti\u1ebfng \u1ed3n c\u1ee7a h\u1ed9p gi\u1ea3m t\u1ed1c n\u1eb1m ngo\u00e0i ph\u1ea1m vi nh\u1ea1y c\u1ea3m v\u1edbi th\u00ednh gi\u00e1c c\u1ee7a con ng\u01b0\u1eddi. Ph\u01b0\u01a1ng ph\u00e1p c\u1ee5 th\u1ec3 c\u1ea7n c\u00f3 c\u00e1c ch\u01b0\u01a1ng tr\u00ecnh v\u00e0 th\u1eed nghi\u1ec7m t\u01b0\u01a1ng \u1ee9ng \u0111\u1ec3 x\u00e1c minh c\u00e1c th\u00f4ng s\u1ed1 b\u00e1nh r\u0103ng t\u1ed1i \u01b0u.<\/p>\n\n\n\n<p>3. T\u1ed1i \u01b0u h\u00f3a c\u1ea5u tr\u00fac v\u1ecf h\u1ed9p gi\u1ea3m t\u1ed1c. M\u1ee5c \u0111\u00edch ch\u00ednh c\u1ee7a vi\u1ec7c t\u1ed1i \u01b0u h\u00f3a v\u1ecf h\u1ed9p l\u00e0 \u0111\u1ec3 c\u1ea3i thi\u1ec7n t\u1ea7n s\u1ed1 t\u1ef1 nhi\u00ean c\u1ee7a n\u00f3. M\u01b0\u1eddi t\u1ea7n s\u1ed1 t\u1ef1 nhi\u00ean \u0111\u1ea7u ti\u00ean c\u1ee7a h\u1ec7 th\u1ed1ng truy\u1ec1n \u0111\u1ed9ng tr\u1ee5c song song nhi\u1ec1u c\u1ea5p th\u01b0\u1eddng th\u1ea5p, th\u01b0\u1eddng n\u1eb1m trong kho\u1ea3ng 50-500 Hz, v\u00e0 d\u1ec5 tr\u00f9ng v\u1edbi t\u1ea7n s\u1ed1 quay c\u1ee7a b\u00e1nh r\u0103ng d\u1eabn \u0111\u1ed9ng v\u00e0 c\u00e1c h\u00e0i c\u1ee7a n\u00f3, g\u00e2y ra hi\u1ec7n t\u01b0\u1ee3ng c\u1ed9ng h\u01b0\u1edfng. D\u1ef1a tr\u00ean c\u1ea5u tr\u00fac h\u1ed9p gi\u1ea3m t\u1ed1c, v\u1eadt li\u1ec7u c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c lo\u1ea1i b\u1ecf \u1edf m\u1ed9t s\u1ed1 v\u1ecb tr\u00ed nh\u1ea5t \u0111\u1ecbnh. \u0110i\u1ec1u n\u00e0y kh\u00f4ng ch\u1ec9 ti\u1ebft ki\u1ec7m chi ph\u00ed v\u1eadt li\u1ec7u m\u00e0 c\u00f2n c\u00f3 th\u1ec3 l\u00e0m t\u0103ng t\u1ea7n s\u1ed1 t\u1ef1 nhi\u00ean c\u1ee7a h\u1ed9p gi\u1ea3m t\u1ed1c v\u00e0 gi\u1ea3m thi\u1ec3u hi\u1ec7u qu\u1ea3 ti\u1ebfng \u1ed3n b\u1ea5t th\u01b0\u1eddng do sai s\u1ed1 l\u1ec7ch t\u00e2m g\u00e2y ra.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"4-conclusion\">4. K\u1ebft lu\u1eadn<\/h2>\n\n\n\n<p>B\u00e0i vi\u1ebft n\u00e0y l\u1ea5y c\u1ea7n c\u1ea9u tr\u00ean cao v\u00e0 h\u1ed9p gi\u1ea3m t\u1ed1c c\u1ee7a n\u00f3 l\u00e0m \u0111\u1ed1i t\u01b0\u1ee3ng nghi\u00ean c\u1ee9u v\u00e0 ph\u00e2n t\u00edch \u1ea3nh h\u01b0\u1edfng c\u1ee7a sai s\u1ed1 l\u1ec7ch t\u00e2m c\u1eb7p b\u00e1nh r\u0103ng \u0111\u1ebfn ti\u1ebfng \u1ed3n b\u1ea5t th\u01b0\u1eddng c\u1ee7a h\u1ed9p gi\u1ea3m t\u1ed1c. C\u00e1c k\u1ebft lu\u1eadn nh\u01b0 sau:<\/p>\n\n\n\n<p>1. Khi x\u00e9t \u0111\u1ebfn sai s\u1ed1 l\u1ec7ch t\u00e2m, v\u1eadn t\u1ed1c g\u00f3c c\u1ee7a b\u00e1nh r\u0103ng b\u1ecb d\u1eabn \u0111\u1ed9ng th\u1ec3 hi\u1ec7n s\u1ef1 dao \u0111\u1ed9ng \u0111\u1ec1u \u0111\u1eb7n. Ph\u1ea1m vi dao \u0111\u1ed9ng t\u1eadp trung trong kho\u1ea3ng 40,5-41,5 rad\/s. \u0110i\u1ec1u n\u00e0y ph\u1ea3n \u00e1nh t\u1ea7n s\u1ed1 quay c\u1ee7a tr\u1ee5c \u0111\u1ea7u v\u00e0o l\u00e0 25 Hz v\u00e0 t\u1ea7n s\u1ed1 quay c\u1ee7a tr\u1ee5c \u0111\u1ea7u ra b\u00e1nh r\u0103ng b\u1ecb d\u1eabn \u0111\u1ed9ng l\u00e0 6,5 Hz, v\u00e0 n\u00f3 ti\u1ebfp t\u1ee5c \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn s\u1ef1 truy\u1ec1n \u0111\u1ed9ng c\u1ee7a c\u1eb7p b\u00e1nh r\u0103ng ti\u1ebfp theo.<\/p>\n\n\n\n<p>2. Khi c\u00f3 sai s\u1ed1 l\u1ec7ch t\u00e2m, ti\u1ebfng \u1ed3n c\u1ea5u tr\u00fac c\u1ee7a b\u1ed9 gi\u1ea3m t\u1ed1c t\u0103ng r\u00f5 r\u1ec7t h\u01a1n \u1edf d\u1ea3i t\u1ea7n s\u1ed1 th\u1ea5p 0-100 Hz. S\u1ef1 kh\u00e1c bi\u1ec7t t\u1ed1i \u0111a \u0111\u1ea1t 15 dB, v\u00e0 m\u1ee9c \u0111\u1ed9 ti\u1ebfng \u1ed3n t\u0103ng l\u00ean 2,5 l\u1ea7n, l\u00e0m t\u0103ng r\u00f5 r\u1ec7t ti\u1ebfng \u1ed3n b\u1ea5t th\u01b0\u1eddng c\u1ee7a h\u1ed9p s\u1ed1.<\/p>\n\n\n\n<p>3. M\u1ed9t s\u1ed1 gi\u1ea3i ph\u00e1p \u0111\u01b0\u1ee3c \u0111\u1ec1 xu\u1ea5t, bao g\u1ed3m c\u1ea3i thi\u1ec7n \u0111\u1ed9 ch\u00ednh x\u00e1c truy\u1ec1n \u0111\u1ed9ng, t\u1ed1i \u01b0u h\u00f3a c\u00e1c th\u00f4ng s\u1ed1 b\u00e1nh r\u0103ng v\u00e0 t\u0103ng t\u1ea7n s\u1ed1 dao \u0111\u1ed9ng ri\u00eang c\u1ee7a c\u1ea5u tr\u00fac.<\/p>","protected":false},"excerpt":{"rendered":"Ti\u1ebfng \u1ed3n t\u1eeb b\u1ed9 gi\u1ea3m t\u1ed1c c\u1ea7n c\u1ea9u tr\u00ean cao c\u00f3 th\u1ec3 x\u1ea3y ra trong qu\u00e1 tr\u00ecnh n\u00e2ng h\u1ea1 v\u00e0 x\u1eed l\u00fd v\u1eadt li\u1ec7u trong x\u01b0\u1edfng, \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn ho\u1ea1t \u0111\u1ed9ng b\u00ecnh th\u01b0\u1eddng c\u1ee7a c\u1ea7n c\u1ea9u. B\u00e0i vi\u1ebft n\u00e0y ph\u00e2n t\u00edch ti\u1ebfng \u1ed3n b\u1ea5t th\u01b0\u1eddng t\u1eeb g\u00f3c \u0111\u1ed9 sai s\u1ed1 l\u1ec7ch t\u00e2m c\u1ee7a c\u1eb7p b\u00e1nh r\u0103ng. D\u1ef1a tr\u00ean k\u1ebft qu\u1ea3 t\u00ednh to\u00e1n ti\u1ebfng \u1ed3n c\u1ea5u tr\u00fac t\u1eeb ph\u00e2n t\u00edch m\u00f4 ph\u1ecfng, b\u00e0i vi\u1ebft c\u0169ng \u0111\u01b0a ra c\u00e1c gi\u1ea3i ph\u00e1p t\u01b0\u01a1ng \u1ee9ng l\u00e0m t\u00e0i li\u1ec7u tham kh\u1ea3o \u0111\u1ec3 c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t ho\u1ea1t \u0111\u1ed9ng c\u1ee7a c\u1ea7n c\u1ea9u tr\u00ean cao. 1 B\u00e1nh r\u0103ng [\u2026]","protected":false},"featured_media":15994,"parent":0,"menu_order":0,"template":"single-SEO-Table.php","posts_category":[197],"posts_tag":[],"acf":[],"_links":{"self":[{"href":"https:\/\/www.hndfcrane.com\/vi\/wp-json\/wp\/v2\/xmxposts\/15972"}],"collection":[{"href":"https:\/\/www.hndfcrane.com\/vi\/wp-json\/wp\/v2\/xmxposts"}],"about":[{"href":"https:\/\/www.hndfcrane.com\/vi\/wp-json\/wp\/v2\/types\/posts"}],"version-history":[{"count":23,"href":"https:\/\/www.hndfcrane.com\/vi\/wp-json\/wp\/v2\/xmxposts\/15972\/revisions"}],"predecessor-version":[{"id":16007,"href":"https:\/\/www.hndfcrane.com\/vi\/wp-json\/wp\/v2\/xmxposts\/15972\/revisions\/16007"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hndfcrane.com\/vi\/wp-json\/wp\/v2\/media\/15994"}],"wp:attachment":[{"href":"https:\/\/www.hndfcrane.com\/vi\/wp-json\/wp\/v2\/media?parent=15972"}],"wp:term":[{"taxonomy":"posts_category","embeddable":true,"href":"https:\/\/www.hndfcrane.com\/vi\/wp-json\/wp\/v2\/posts_category?post=15972"},{"taxonomy":"posts_tag","embeddable":true,"href":"https:\/\/www.hndfcrane.com\/vi\/wp-json\/wp\/v2\/posts_tag?post=15972"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}