{"id":2789,"date":"2025-10-03T14:16:35","date_gmt":"2025-10-03T14:16:35","guid":{"rendered":"https:\/\/productionscrews.com\/"},"modified":"2025-10-03T14:16:35","modified_gmt":"2025-10-03T14:16:35","slug":"ultimate-guide-to-fatigue-testing-why-materials-fail-under-repeated-stress","status":"publish","type":"post","link":"https:\/\/productionscrews.com\/vi\/ultimate-guide-to-fatigue-testing-why-materials-fail-under-repeated-stress\/","title":{"rendered":"H\u01b0\u1edbng D\u1eabn To\u00e0n Di\u1ec7n v\u1ec1 Ki\u1ec3m Tra M\u1ec7t M\u1ecfi: T\u1ea1i Sao V\u1eadt Li\u1ec7u Th\u1ea5t B\u1ea1i D\u01b0\u1edbi \u00c1p L\u1ef1c L\u1eb7p L\u1ea1i"},"content":{"rendered":"

Hi\u1ec3u R\u00f5 Ki\u1ec3m Tra M\u1ec7t M\u1ecfi: C\u00e1ch Ch\u00fang Ta Ki\u1ec3m Tra \u0110\u1ed9 B\u1ec1n V\u1eadt Li\u1ec7u Theo Th\u1eddi Gian<\/h2>\n

V\u01b0\u1ee3t Ra Ngo\u00e0i \u0110\u1ed9 B\u1ec1n C\u01a1 B\u1ea3n<\/h2>\n

Trong k\u1ef9 thu\u1eadt v\u00e0 khoa h\u1ecdc v\u1eadt li\u1ec7u, vi\u1ec7c bi\u1ebft m\u1ed9t v\u1eadt li\u1ec7u c\u00f3 th\u1ec3 ch\u1ecbu l\u1ef1c bao nhi\u00eau trong m\u1ed9t l\u1ea7n k\u00e9o kh\u00f4ng ph\u1ea3n \u00e1nh to\u00e0n b\u1ed9 c\u00e2u chuy\u1ec7n. Trong khi \u201c\u0111\u1ed9 b\u1ec1n k\u00e9o t\u1ed1i \u0111a\u201d cho th\u1ea5y t\u1ea3i tr\u1ecdng t\u1ed1i \u0111a v\u1eadt li\u1ec7u c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u1ef1ng m\u1ed9t l\u1ea7n, n\u00f3 kh\u00f4ng d\u1ef1 \u0111o\u00e1n \u0111\u01b0\u1ee3c c\u00e1ch v\u1eadt li\u1ec7u \u0111\u00f3 s\u1ebd ph\u1ea3n \u1ee9ng d\u01b0\u1edbi c\u00e1c t\u1ea3i l\u1eb7p l\u1ea1i l\u00ean xu\u1ed1ng theo th\u1eddi gian. \u0110\u00e2y l\u00e0 n\u01a1i s\u1ee9c b\u1ec1n c\u1ee7a v\u1eadt li\u1ec7u tr\u1edf n\u00ean quan tr\u1ecdng \u2013 m\u1ed9t l\u0129nh v\u1ef1c then ch\u1ed1t \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o c\u00e1c c\u1ea5u tr\u00fac gi\u1eef an to\u00e0n v\u00e0 m\u1ea1nh m\u1ebd trong nhi\u1ec1u n\u0103m.<\/p>\n

V\u1ea5n \u0110\u1ec1 Ch\u00ednh V\u1edbi C\u00e1c S\u1ef1 C\u1ed1<\/h3>\n

H\u1ea7u h\u1ebft c\u00e1c s\u1ef1 c\u1ed1 c\u01a1 kh\u00ed x\u1ea3y ra trong th\u1ef1c t\u1ebf \u2013 h\u01a1n 80% \u2013 kh\u00f4ng do m\u1ed9t qu\u00e1 t\u1ea3i l\u1edbn g\u00e2y ra. Thay v\u00e0o \u0111\u00f3, ch\u00fang x\u1ea3y ra do m\u1ec7t m\u1ecfi. \u0110i\u1ec1u n\u00e0y x\u1ea3y ra khi m\u1ed9t v\u1eadt li\u1ec7u b\u1ecb t\u1ea3i v\u00e0 th\u00e1o t\u1ea3i \u0111i \u0111i l\u1ea1i l\u1ea1i nhi\u1ec1u l\u1ea7n. Sau h\u00e0ng ngh\u00ecn ho\u1eb7c h\u00e0ng tri\u1ec7u chu k\u1ef3 nh\u01b0 v\u1eady, \u00e1p l\u1ef1c l\u1eb7p l\u1ea1i g\u00e2y ra s\u1ef1 c\u1ed1 \u1edf m\u1ee9c th\u1ea5p h\u01a1n nhi\u1ec1u so v\u1edbi \u0111\u1ed9 b\u1ec1n t\u1ed1i \u0111a c\u1ee7a v\u1eadt li\u1ec7u<\/a>. H\u00e3y ngh\u0129 v\u1ec1 vi\u1ec7c u\u1ed1n cong k\u1eb9p gi\u1ea5y qua l\u1ea1i cho \u0111\u1ebfn khi n\u00f3 g\u00e3y \u2013 l\u1ea7n u\u1ed1n \u0111\u1ea7u ti\u00ean kh\u00f4ng l\u00e0m g\u00e3y, nh\u01b0ng l\u00e0m \u0111i l\u00e0m l\u1ea1i nhi\u1ec1u l\u1ea7n th\u00ec c\u00f3.<\/p>\n

Ki\u1ec3m Tra M\u1ec7t M\u1ecfi L\u00e0 G\u00ec<\/h3>\n

\u0110\u1ec3 ng\u0103n ch\u1eb7n nh\u1eefng v\u1ea5n \u0111\u1ec1 n\u00e0y, c\u00e1c k\u1ef9 s\u01b0 s\u1eed d\u1ee5ng m\u1ed9t quy tr\u00ecnh ki\u1ec3m tra \u0111\u1eb7c bi\u1ec7t<\/a>. Ki\u1ec3m tra m\u1ec7t m\u1ecfi l\u00e0 qu\u00e1 tr\u00ecnh th\u1eed nghi\u1ec7m nh\u1eb1m x\u00e1c \u0111\u1ecbnh kh\u1ea3 n\u0103ng ch\u1ed1ng l\u1ea1i h\u01b0 h\u1ecfng d\u1ea7n d\u1ea7n c\u1ee7a v\u1eadt li\u1ec7u ho\u1eb7c b\u1ed9 ph\u1eadn khi b\u1ecb t\u1ea3i l\u1eb7p l\u1ea1i. N\u00f3 kh\u00f4ng ch\u1ec9 l\u00e0 ki\u1ec3m tra ch\u1ea5t l\u01b0\u1ee3ng \u2013 m\u00e0 c\u00f2n l\u00e0 c\u00f4ng c\u1ee5 thi\u1ebft k\u1ebf c\u01a1 b\u1ea3n d\u00f9ng \u0111\u1ec3 t\u1ea1o d\u1eef li\u1ec7u d\u1ef1 \u0111o\u00e1n tu\u1ed5i th\u1ecd c\u1ee7a s\u1ea3n ph\u1ea9m, x\u00e1c nh\u1eadn c\u00e1c l\u1ef1a ch\u1ecdn thi\u1ebft k\u1ebf, v\u00e0 ng\u0103n ng\u1eeba c\u00e1c s\u1ef1 c\u1ed1 nguy hi\u1ec3m trong m\u1ecdi th\u1ee9 t\u1eeb \u0111\u1ed9ng c\u01a1 m\u00e1y bay \u0111\u1ebfn thi\u1ebft b\u1ecb y t\u1ebf.<\/p>\n

N\u1ed9i Dung B\u00e0i Vi\u1ebft N\u00e0y Bao G\u1ed3m<\/h3>\n

Ph\u00e2n t\u00edch n\u00e0y s\u1ebd cung c\u1ea5p cho b\u1ea1n c\u00e1i nh\u00ecn to\u00e0n di\u1ec7n v\u1ec1 c\u00e1c nguy\u00ean l\u00fd \u0111\u1eb1ng sau m\u1ec7t m\u1ecfi v\u1eadt li\u1ec7u. Ch\u00fang t\u00f4i b\u1eaft \u0111\u1ea7u v\u1edbi v\u1eadt l\u00fd c\u01a1 b\u1ea3n<\/a> c\u00e1c qu\u00e1 tr\u00ecnh h\u00ecnh th\u00e0nh v\u00e0 ph\u00e1t tri\u1ec3n c\u1ee7a v\u1ebft n\u1ee9t \u1edf c\u1ea5p \u0111\u1ed9 nh\u1ecf. Sau \u0111\u00f3, ch\u00fang t\u00f4i ph\u00e2n t\u00edch c\u00e1c c\u00f4ng c\u1ee5 thi\u1ebft y\u1ebfu c\u1ee7a ph\u00e2n t\u00edch m\u1ec7t m\u1ecfi, nh\u01b0 \u0111\u01b0\u1eddng cong S-N, v\u00e0 so s\u00e1nh c\u00e1c ph\u01b0\u01a1ng ph\u00e1p ki\u1ec3m tra kh\u00e1c nhau. Cu\u1ed1i c\u00f9ng, ch\u00fang t\u00f4i s\u1ebd h\u01b0\u1edbng d\u1eabn c\u00e1ch th\u1ef1c hi\u1ec7n m\u1ed9t b\u00e0i ki\u1ec3m tra m\u1ec7t m\u1ecfi, kh\u00e1m ph\u00e1 c\u00e1c y\u1ebfu t\u1ed1 n\u00e2ng cao \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn k\u1ebft qu\u1ea3, v\u00e0 th\u1ea3o lu\u1eadn v\u1ec1 c\u00e1c ti\u00eau chu\u1ea9n ng\u00e0nh \u0111\u1ea3m b\u1ea3o d\u1eef li\u1ec7u \u0111\u00e1ng tin c\u1eady.<\/p>\n

V\u1eadt L\u00fd C\u01a1 B\u1ea3n c\u1ee7a M\u1ec7t M\u1ecfi<\/h2>\n

\u0110\u1ec3 th\u1ef1c s\u1ef1 hi\u1ec3u v\u1ec1 m\u1ec7t m\u1ecfi, ch\u00fang ta c\u1ea7n nh\u00ecn xa h\u01a1n nh\u1eefng g\u00ec m\u1eaft th\u01b0\u1eddng th\u1ea5y v\u00e0 xem x\u00e9t nh\u1eefng g\u00ec x\u1ea3y ra b\u00ean trong c\u1ea5u tr\u00fac c\u1ee7a v\u1eadt li\u1ec7u. S\u1ef1 c\u1ed1 m\u1ec7t m\u1ecfi kh\u00f4ng x\u1ea3y ra ngay l\u1eadp t\u1ee9c \u2013 \u0111\u00f3 l\u00e0 qu\u00e1 tr\u00ecnh t\u00edch t\u1ee5 h\u01b0 h\u1ecfng d\u1ea7n d\u1ea7n. N\u00f3 di\u1ec5n ra theo m\u1ed9t chu\u1ed7i c\u00e1c giai \u0111o\u1ea1n r\u00f5 r\u00e0ng, m\u1ed7i giai \u0111o\u1ea1n \u0111\u1ec1u b\u1ecb th\u00fac \u0111\u1ea9y b\u1edfi c\u01a1 h\u1ecdc c\u1ee7a bi\u1ebfn d\u1ea1ng l\u1eb7p l\u1ea1i \u1edf c\u1ea5p \u0111\u1ed9 vi m\u00f4.<\/p>\n

Ba Giai \u0110o\u1ea1n c\u1ee7a S\u1ef1 C\u1ed1<\/h3>\n

Qu\u00e1 tr\u00ecnh t\u1eeb m\u1ed9t b\u1ed9 ph\u1eadn ho\u00e0n h\u1ea3o \u0111\u1ebfn khi b\u1ecb g\u00e3y lu\u00f4n c\u00f3 th\u1ec3 ph\u00e2n chia th\u00e0nh ba giai \u0111o\u1ea1n. Hi\u1ec3u r\u00f5 chu\u1ed7i n\u00e0y l\u00e0 ch\u00eca kh\u00f3a \u0111\u1ec3 ch\u1ea9n \u0111o\u00e1n c\u00e1c s\u1ef1 c\u1ed1 v\u00e0 thi\u1ebft k\u1ebf ch\u1ed1ng l\u1ea1i ch\u00fang.<\/p>\n

    \n
  1. Kh\u1edfi \u0110\u1ea7u V\u1ebft N\u1ee9t. Qu\u00e1 tr\u00ecnh b\u1eaft \u0111\u1ea7u t\u1ea1i c\u00e1c \u0111i\u1ec3m ch\u1ecbu l\u1ef1c nh\u1ecf. \u0110\u00e2y c\u00f3 th\u1ec3 l\u00e0 c\u00e1c l\u1ed7i t\u1ef1 nhi\u00ean c\u1ee7a v\u1eadt li\u1ec7u nh\u01b0 h\u1ea1t, l\u1ed7, ho\u1eb7c ranh gi\u1edbi h\u1ea1t. Ch\u00fang c\u0169ng c\u00f3 th\u1ec3 l\u00e0 c\u00e1c \u0111\u1eb7c \u0111i\u1ec3m h\u00ecnh d\u1ea1ng, nh\u01b0 g\u00f3c nh\u1ecdn, ho\u1eb7c th\u1eadm ch\u00ed c\u00e1c v\u1ea5n \u0111\u1ec1 b\u1ec1 m\u1eb7t nh\u01b0 v\u1ebft c\u1eaft d\u1ee5ng c\u1ee5 v\u00e0 v\u1ebft tr\u1ea7y x\u01b0\u1edbc. D\u01b0\u1edbi t\u00e1c \u0111\u1ed9ng c\u1ee7a t\u1ea3i l\u1eb7p l\u1ea1i, bi\u1ebfn d\u1ea1ng d\u1ebbo t\u1eadp trung t\u1ea1i c\u00e1c khu v\u1ef1c nh\u1ecf n\u00e0y. S\u1ef1 tr\u01b0\u1ee3t l\u1eb7p l\u1ea1i d\u1ecdc theo c\u00e1c m\u1eb7t ph\u1eb3ng tinh th\u1ec3 cu\u1ed1i c\u00f9ng d\u1eabn \u0111\u1ebfn s\u1ef1 h\u00ecnh th\u00e0nh c\u00e1c d\u1ea3i tr\u01b0\u1ee3t li\u00ean t\u1ee5c, sau \u0111\u00f3 ph\u00e1t tri\u1ec3n th\u00e0nh m\u1ed9t ho\u1eb7c nhi\u1ec1u v\u1ebft n\u1ee9t nh\u1ecf. Giai \u0111o\u1ea1n n\u00e0y c\u00f3 th\u1ec3 chi\u1ebfm ph\u1ea7n l\u1edbn tu\u1ed5i th\u1ecd m\u1ec7t m\u1ecfi t\u1ed5ng th\u1ec3 c\u1ee7a b\u1ed9 ph\u1eadn.<\/li>\n
  2. S\u1ef1 ph\u00e1t tri\u1ec3n v\u1ebft n\u1ee9t. Khi m\u1ed9t v\u1ebft n\u1ee9t nh\u1ecf h\u00ecnh th\u00e0nh, n\u00f3 b\u01b0\u1edbc v\u00e0o giai \u0111o\u1ea1n ph\u00e1t tri\u1ec3n. V\u1edbi m\u1ed7i chu k\u1ef3 t\u1ea3i m\u1edbi, v\u1ebft n\u1ee9t di chuy\u1ec3n m\u1ed9t l\u01b0\u1ee3ng nh\u1ecf qua v\u1eadt li\u1ec7u. \u1ee8ng su\u1ea5t t\u1ea1i \u0111\u1ea7u v\u1ebft n\u1ee9t t\u1eadp trung cao, g\u00e2y ra bi\u1ebfn d\u1ea1ng d\u1ebbo c\u1ee5c b\u1ed9 \u0111\u1ea9y v\u1ebft n\u1ee9t v\u1ec1 ph\u00eda tr\u01b0\u1edbc. Tr\u00ean b\u1ec1 m\u1eb7t g\u00e3y, s\u1ef1 ph\u00e1t tri\u1ec3n \u1ed5n \u0111\u1ecbnh, theo chu k\u1ef3 n\u00e0y th\u01b0\u1eddng \u0111\u1ec3 l\u1ea1i nh\u1eefng d\u1ea5u v\u1ebft nh\u1ecf g\u1ecdi l\u00e0 v\u00e2n. Nh\u1eefng d\u1ea5u v\u1ebft n\u00e0y l\u00e0 b\u1eb1ng ch\u1ee9ng cho c\u00e1c nh\u00e0 ph\u00e2n t\u00edch h\u01b0 h\u1ecfng, v\u00ec m\u1ed7i d\u1ea5u v\u1ebft t\u01b0\u01a1ng \u1ee9ng v\u1edbi m\u1ed9t chu k\u1ef3 t\u1ea3i duy nh\u1ea5t, cho ph\u00e9p t\u00e1i t\u1ea1o l\u1ecbch s\u1eed ph\u00e1t tri\u1ec3n c\u1ee7a v\u1ebft n\u1ee9t sau khi h\u1ecfng.<\/li>\n
  3. G\u00e3y cu\u1ed1i c\u00f9ng. V\u1ebft n\u1ee9t ti\u1ebfp t\u1ee5c ph\u00e1t tri\u1ec3n, l\u00e0m gi\u1ea3m di\u1ec7n t\u00edch ch\u1ecbu t\u1ea3i c\u1ee7a b\u1ed9 ph\u1eadn. \u0110i\u1ec1u n\u00e0y ti\u1ebfp t\u1ee5c cho \u0111\u1ebfn khi ph\u1ea7n v\u1eadt li\u1ec7u c\u00f2n l\u1ea1i, kh\u00f4ng b\u1ecb n\u1ee9t kh\u00f4ng c\u00f2n kh\u1ea3 n\u0103ng ch\u1ecbu t\u1ea3i tr\u1ecdng t\u00e1c d\u1ee5ng. T\u1ea1i th\u1eddi \u0111i\u1ec3m quan tr\u1ecdng n\u00e0y, s\u1ef1 g\u00e3y \u0111\u1ed9t ng\u1ed9t cu\u1ed1i c\u00f9ng x\u1ea3y ra. S\u1ef1 h\u1ecfng h\u00f3c cu\u1ed1i c\u00f9ng n\u00e0y th\u01b0\u1eddng nhanh ch\u00f3ng v\u00e0 th\u1ea3m kh\u1ed1c, v\u00ec m\u1eb7t c\u1eaft ngang c\u00f2n l\u1ea1i b\u1ecb h\u1ecfng trong m\u1ed9t s\u1ef1 ki\u1ec7n qu\u00e1 t\u1ea3i duy nh\u1ea5t.<\/li>\n<\/ol>\n

    G\u00e3y d\u1ebbo so v\u1edbi g\u00e3y gi\u00f2n<\/h3>\n

    H\u00ecnh d\u1ea1ng c\u1ee7a b\u1ec1 m\u1eb7t g\u00e3y cu\u1ed1i c\u00f9ng cung c\u1ea5p nh\u1eefng manh m\u1ed1i c\u00f3 gi\u00e1 tr\u1ecb v\u1ec1 h\u00e0nh vi c\u1ee7a v\u1eadt li\u1ec7u. M\u1ed9t v\u1ebft g\u00e3y m\u1ecfi d\u1ebbo \u0111\u01b0\u1ee3c \u0111\u1eb7c tr\u01b0ng b\u1edfi h\u00ecnh d\u1ea1ng \u201cch\u00e9n v\u00e0 n\u00f3n\u201d v\u00e0 v\u1ebb ngo\u00e0i x\u1ec9n m\u00e0u, d\u1ea1ng s\u1ee3i, cho th\u1ea5y s\u1ef1 bi\u1ebfn d\u1ea1ng d\u1ebbo \u0111\u00e1ng k\u1ec3 tr\u01b0\u1edbc khi h\u1ecfng. Ng\u01b0\u1ee3c l\u1ea1i, m\u1ed9t v\u1ebft g\u00e3y m\u1ecfi gi\u00f2n th\u01b0\u1eddng ph\u1eb3ng, s\u00e1ng v\u00e0 c\u00f3 c\u1ea5u tr\u00fac tinh th\u1ec3, v\u1edbi c\u00e1c d\u1ea5u chevron h\u01b0\u1edbng ng\u01b0\u1ee3c l\u1ea1i n\u01a1i v\u1ebft n\u1ee9t b\u1eaft \u0111\u1ea7u. \u0110i\u1ec1u n\u00e0y cho th\u1ea5y m\u1ed9t v\u1ebft g\u00e3y nhanh v\u1edbi \u00edt ho\u1eb7c kh\u00f4ng c\u00f3 bi\u1ebfn d\u1ea1ng d\u1ebbo. Quan s\u00e1t nh\u1eefng \u0111\u1eb7c \u0111i\u1ec3m n\u00e0y gi\u00fap k\u1ef9 s\u01b0 hi\u1ec3u \u0111\u01b0\u1ee3c ch\u1ebf \u0111\u1ed9 h\u1ecfng h\u00f3c v\u00e0 ph\u1ea3n \u1ee9ng c\u1ee7a v\u1eadt li\u1ec7u d\u01b0\u1edbi \u1ee9ng su\u1ea5t l\u1eb7p \u0111i l\u1eb7p l\u1ea1i.<\/p>\n

    \"Bu <\/a><\/p>\n

    \u0110\u01b0\u1eddng cong S-N<\/h2>\n

    C\u00f4ng c\u1ee5 c\u01a1 b\u1ea3n nh\u1ea5t trong ph\u00e2n t\u00edch m\u1ecfi l\u00e0 \u0111\u01b0\u1eddng cong \u1ee8ng su\u1ea5t-Tu\u1ed5i th\u1ecd, th\u01b0\u1eddng \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 \u0111\u01b0\u1eddng cong S-N. \u0110\u1ed3 th\u1ecb n\u00e0y l\u00e0 n\u1ec1n t\u1ea3ng c\u1ee7a thi\u1ebft k\u1ebf m\u1ecfi cho c\u00e1c b\u1ed9 ph\u1eadn \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf cho tu\u1ed5i th\u1ecd s\u1eed d\u1ee5ng l\u00e2u d\u00e0i. N\u00f3 cung c\u1ea5p m\u1ed9t m\u1ed1i quan h\u1ec7 tr\u1ef1c ti\u1ebfp, th\u1ef1c nghi\u1ec7m gi\u1eefa k\u00edch th\u01b0\u1edbc c\u1ee7a \u1ee9ng su\u1ea5t l\u1eb7p \u0111i l\u1eb7p l\u1ea1i v\u00e0 s\u1ed1 chu k\u1ef3 m\u00e0 v\u1eadt li\u1ec7u c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c tr\u01b0\u1edbc khi h\u1ecfng.<\/p>\n

    V\u1ebd \u0111\u1ed3 th\u1ecb \u1ee8ng su\u1ea5t so v\u1edbi Tu\u1ed5i th\u1ecd<\/h3>\n

    \u0110\u01b0\u1eddng cong S-N l\u00e0 m\u1ed9t \u0111\u1ed3 th\u1ecb hi\u1ec3n th\u1ecb d\u1eef li\u1ec7u m\u1ecfi m\u1ed9t c\u00e1ch tr\u1ef1c quan. Tr\u1ee5c tung bi\u1ec3u th\u1ecb bi\u00ean \u0111\u1ed9 \u1ee9ng su\u1ea5t (S), \u0111o k\u00edch th\u01b0\u1edbc c\u1ee7a \u1ee9ng su\u1ea5t l\u1eb7p \u0111i l\u1eb7p l\u1ea1i. Tr\u1ee5c ho\u00e0nh bi\u1ec3u th\u1ecb s\u1ed1 chu k\u1ef3 \u0111\u1ebfn khi h\u1ecfng (N), h\u1ea7u nh\u01b0 lu\u00f4n \u0111\u01b0\u1ee3c v\u1ebd tr\u00ean thang logarit \u0111\u1ec3 x\u1eed l\u00fd m\u1ed9t ph\u1ea1m vi gi\u00e1 tr\u1ecb r\u1ea5t r\u1ed9ng, t\u1eeb h\u00e0ng ngh\u00ecn \u0111\u1ebfn h\u00e0ng t\u1ef7 chu k\u1ef3.<\/p>\n

    Qu\u00e1 tr\u00ecnh t\u1ea1o \u0111\u01b0\u1eddng cong S-N bao g\u1ed3m th\u1eed nghi\u1ec7m m\u1ed9t lo\u1ea1t c\u00e1c m\u1eabu v\u1eadt gi\u1ed1ng h\u1ec7t nhau. M\u1ed7i m\u1eabu v\u1eadt nh\u1eadn \u0111\u01b0\u1ee3c t\u1ea3i tr\u1ecdng l\u1eb7p \u0111i l\u1eb7p l\u1ea1i bi\u00ean \u0111\u1ed9 kh\u00f4ng \u0111\u1ed5i \u1edf m\u1ed9t m\u1ee9c \u1ee9ng su\u1ea5t c\u1ee5 th\u1ec3 cho \u0111\u1ebfn khi n\u00f3 b\u1ecb h\u1ecfng. S\u1ed1 chu k\u1ef3 \u0111\u1ebfn khi h\u1ecfng \u0111\u01b0\u1ee3c ghi l\u1ea1i. Qu\u00e1 tr\u00ecnh n\u00e0y \u0111\u01b0\u1ee3c l\u1eb7p l\u1ea1i cho nhi\u1ec1u m\u1eabu v\u1eadt \u1edf c\u00e1c m\u1ee9c \u1ee9ng su\u1ea5t kh\u00e1c nhau, th\u1ea5p h\u01a1n d\u1ea7n. C\u00e1c \u0111i\u1ec3m d\u1eef li\u1ec7u k\u1ebft qu\u1ea3 (S, N) sau \u0111\u00f3 \u0111\u01b0\u1ee3c v\u1ebd v\u00e0 m\u1ed9t \u0111\u01b0\u1eddng cong \u0111\u01b0\u1ee3c kh\u1edbp qua ch\u00fang \u0111\u1ec3 bi\u1ec3u th\u1ecb h\u00e0nh vi m\u1ecfi trung b\u00ecnh c\u1ee7a v\u1eadt li\u1ec7u.<\/p>\n

    C\u00e1c \u0111\u1eb7c \u0111i\u1ec3m ch\u00ednh c\u1ee7a \u0111\u01b0\u1eddng cong<\/h3>\n

    H\u00ecnh d\u1ea1ng c\u1ee7a \u0111\u01b0\u1eddng cong S-N ti\u1ebft l\u1ed9 m\u1ed9t s\u1ed1 thu\u1ed9c t\u00ednh quan tr\u1ecdng v\u1ec1 hi\u1ec7u su\u1ea5t m\u1ecfi c\u1ee7a v\u1eadt li\u1ec7u. C\u00e1c k\u1ef9 s\u01b0 ph\u1ea3i c\u00f3 kh\u1ea3 n\u0103ng x\u00e1c \u0111\u1ecbnh v\u00e0 gi\u1ea3i th\u00edch c\u00e1c \u0111\u1eb7c \u0111i\u1ec3m n\u00e0y \u0111\u1ec3 \u0111\u01b0a ra c\u00e1c quy\u1ebft \u0111\u1ecbnh thi\u1ebft k\u1ebf t\u1ed1t.<\/p>\n

    M\u1ed9t s\u1ef1 ph\u00e2n bi\u1ec7t ch\u00ednh \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n tr\u00ean \u0111\u01b0\u1eddng cong l\u00e0 gi\u1eefa M\u1ecfi chu k\u1ef3 cao (HCF) v\u00e0 M\u1ecfi chu k\u1ef3 th\u1ea5p (LCF). M\u1ecfi chu k\u1ef3 th\u1ea5p th\u01b0\u1eddng x\u1ea3y ra \u1edf m\u1ee9c \u1ee9ng su\u1ea5t cao g\u00e2y ra bi\u1ebfn d\u1ea1ng d\u1ebbo v\u00e0 d\u1eabn \u0111\u1ebfn h\u1ecfng h\u00f3c trong m\u1ed9t s\u1ed1 l\u01b0\u1ee3ng chu k\u1ef3 t\u01b0\u01a1ng \u0111\u1ed1i nh\u1ecf (v\u00ed d\u1ee5: \u00edt h\u01a1n 10^4 ho\u1eb7c 10^5 chu k\u1ef3). M\u1ecfi chu k\u1ef3 cao x\u1ea3y ra \u1edf m\u1ee9c \u1ee9ng su\u1ea5t th\u1ea5p h\u01a1n, n\u01a1i bi\u1ebfn d\u1ea1ng ch\u1ee7 y\u1ebfu l\u00e0 \u0111\u00e0n h\u1ed3i v\u00e0 h\u1ecfng h\u00f3c \u0111\u00f2i h\u1ecfi m\u1ed9t s\u1ed1 l\u01b0\u1ee3ng chu k\u1ef3 r\u1ea5t l\u1edbn.<\/p>\n

    \u0110\u1ed1i v\u1edbi m\u1ed9t s\u1ed1 v\u1eadt li\u1ec7u nh\u1ea5t \u0111\u1ecbnh, \u0111\u1eb7c bi\u1ec7t l\u00e0 g\u1ed1c s\u1eaft h\u1ee3p kim nh\u01b0 th\u00e9p<\/a> v\u00e0 titan, \u0111\u01b0\u1eddng cong S-N tr\u1edf n\u00ean n\u1eb1m ngang \u1edf m\u1ed9t s\u1ed1 l\u01b0\u1ee3ng chu k\u1ef3 cao. M\u1ee9c \u1ee9ng su\u1ea5t n\u00e0y \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 Gi\u1edbi h\u1ea1n b\u1ec1n ho\u1eb7c Gi\u1edbi h\u1ea1n m\u1ecfi. D\u01b0\u1edbi gi\u1edbi h\u1ea1n n\u00e0y, v\u1eadt li\u1ec7u v\u1ec1 m\u1eb7t l\u00fd thuy\u1ebft c\u00f3 th\u1ec3 x\u1eed l\u00fd v\u00f4 s\u1ed1 chu k\u1ef3 t\u1ea3i m\u00e0 kh\u00f4ng b\u1ecb h\u1ecfng. Kh\u00e1i ni\u1ec7m n\u00e0y r\u1ea5t quan tr\u1ecdng \u0111\u1ec3 thi\u1ebft k\u1ebf c\u00e1c b\u1ed9 ph\u1eadn ph\u1ea3i ho\u1ea1t \u0111\u1ed9ng trong th\u1eddi gian r\u1ea5t d\u00e0i, ch\u1eb3ng h\u1ea1n nh\u01b0 tr\u1ee5c khu\u1ef7u \u0111\u1ed9ng c\u01a1 ho\u1eb7c l\u00f2 xo van.<\/p>\n

    Nhi\u1ec1u v\u1eadt li\u1ec7u kh\u00f4ng ph\u1ea3i g\u1ed1c s\u1eaft, ch\u1eb3ng h\u1ea1n nh\u01b0 h\u1ee3p kim nh\u00f4m v\u00e0 \u0111\u1ed3ng, kh\u00f4ng hi\u1ec3n th\u1ecb gi\u1edbi h\u1ea1n b\u1ec1n th\u1ef1c s\u1ef1. \u0110\u01b0\u1eddng cong S-N c\u1ee7a ch\u00fang ti\u1ebfp t\u1ee5c d\u1ed1c xu\u1ed1ng, ngay c\u1ea3 \u1edf s\u1ed1 l\u01b0\u1ee3ng chu k\u1ef3 r\u1ea5t cao. \u0110\u1ed1i v\u1edbi nh\u1eefng v\u1eadt li\u1ec7u n\u00e0y, c\u00e1c k\u1ef9 s\u01b0 x\u00e1c \u0111\u1ecbnh \u0110\u1ed9 b\u1ec1n m\u1ecfi. \u0110\u00e2y l\u00e0 m\u1ee9c \u1ee9ng su\u1ea5t m\u00e0 v\u1eadt li\u1ec7u c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c trong m\u1ed9t s\u1ed1 chu k\u1ef3 c\u1ee5 th\u1ec3, v\u00ed d\u1ee5: 500 tri\u1ec7u chu k\u1ef3 (5\u00d710^8). Khi thi\u1ebft k\u1ebf v\u1edbi nh\u1eefng v\u1eadt li\u1ec7u n\u00e0y, ng\u01b0\u1eddi ta ph\u1ea3i lu\u00f4n ch\u1ec9 \u0111\u1ecbnh tu\u1ed5i th\u1ecd m\u1ecfi li\u00ean quan \u0111\u1ebfn m\u1ed9t \u0111\u1ed9 b\u1ec1n m\u1ecfi nh\u1ea5t \u0111\u1ecbnh.<\/p>\n

    So s\u00e1nh c\u00e1c ph\u01b0\u01a1ng ph\u00e1p th\u1eed nghi\u1ec7m<\/h2>\n

    M\u1eb7c d\u00f9 \u0111\u01b0\u1eddng cong S-N l\u00e0 m\u1ed9t c\u00f4ng c\u1ee5 n\u1ec1n t\u1ea3ng, nh\u01b0ng n\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 ph\u01b0\u01a1ng ph\u00e1p duy nh\u1ea5t \u0111\u1ec3 ph\u00e2n t\u00edch m\u1ecfi. K\u1ef9 thu\u1eadt hi\u1ec7n \u0111\u1ea1i<\/a> s\u1eed d\u1ee5ng m\u1ed9t s\u1ed1 ph\u01b0\u01a1ng ph\u00e1p ri\u00eang bi\u1ec7t, m\u1ed7i ph\u01b0\u01a1ng ph\u00e1p c\u00f3 c\u00e1c nguy\u00ean t\u1eafc v\u00e0 \u1ee9ng d\u1ee5ng l\u00fd t\u01b0\u1edfng ri\u00eang. Vi\u1ec7c l\u1ef1a ch\u1ecdn ph\u01b0\u01a1ng ph\u00e1p ch\u00ednh x\u00e1c ph\u1ee5 thu\u1ed9c v\u00e0o ch\u1ebf \u0111\u1ed9 h\u1ecfng h\u00f3c d\u1ef1 ki\u1ebfn, h\u00ecnh d\u1ea1ng c\u1ee7a b\u1ed9 ph\u1eadn v\u00e0 tri\u1ebft l\u00fd thi\u1ebft k\u1ebf. Ba khu\u00f4n kh\u1ed5 ch\u00ednh l\u00e0 c\u00e1c ph\u01b0\u01a1ng ph\u00e1p \u1ee8ng su\u1ea5t-Tu\u1ed5i th\u1ecd (S-N), Bi\u1ebfn d\u1ea1ng-Tu\u1ed5i th\u1ecd (E-N) v\u00e0 C\u01a1 h\u1ecdc ph\u00e1 h\u1ee7y \u0111\u00e0n h\u1ed3i tuy\u1ebfn t\u00ednh (LEFM).<\/p>\n

    Ph\u01b0\u01a1ng ph\u00e1p Stress-Life (S-N)<\/h3>\n

    Ph\u01b0\u01a1ng ph\u00e1p Stress-Life l\u00e0 ph\u01b0\u01a1ng ph\u00e1p c\u1ed5 nh\u1ea5t v\u00e0 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i nh\u1ea5t. Nh\u01b0 \u0111\u00e3 th\u1ea3o lu\u1eadn tr\u01b0\u1edbc \u0111\u00f3, n\u00f3 li\u00ean quan \u0111\u1ebfn bi\u00ean \u0111\u1ed9 \u1ee9ng su\u1ea5t danh ngh\u0129a trong m\u1ed9t b\u1ed9 ph\u1eadn v\u1edbi tu\u1ed5i th\u1ecd t\u1ed5ng th\u1ec3 c\u1ee7a n\u00f3. \u1ee8ng d\u1ee5ng ch\u00ednh c\u1ee7a n\u00f3 l\u00e0 trong c\u00e1c t\u00ecnh hu\u1ed1ng M\u1ec7t m\u1ecfi chu k\u1ef3 cao (HCF), n\u01a1i ph\u1ea7n l\u1edbn ph\u1ea3n \u1ee9ng c\u1ee7a v\u1eadt li\u1ec7u l\u00e0 \u0111\u00e0n h\u1ed3i v\u00e0 bi\u1ebfn d\u1ea1ng d\u1ebbo t\u1eadp trung cao. Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y gi\u1ea3 \u0111\u1ecbnh b\u1ed9 ph\u1eadn ban \u0111\u1ea7u kh\u00f4ng c\u00f3 v\u1ebft n\u1ee9t v\u00e0 xem vi\u1ec7c b\u1eaft \u0111\u1ea7u v\u00e0 lan truy\u1ec1n v\u1ebft n\u1ee9t nh\u01b0 m\u1ed9t giai \u0111o\u1ea1n \u201ctu\u1ed5i th\u1ecd t\u1ed5ng th\u1ec3\u201d. N\u00f3 ph\u00f9 h\u1ee3p nh\u1ea5t \u0111\u1ec3 thi\u1ebft k\u1ebf c\u00e1c b\u1ed9 ph\u1eadn d\u1ef1 \u0111\u1ecbnh c\u00f3 tu\u1ed5i th\u1ecd r\u1ea5t d\u00e0i ho\u1eb7c \u201cv\u00f4 h\u1ea1n\u201d, nh\u01b0 tr\u1ee5c quay, tr\u1ee5c xe, v\u00e0 l\u00f2 xo hi\u1ec7u su\u1ea5t cao, n\u01a1i c\u00e1c \u1ee9ng su\u1ea5t v\u1eadn h\u00e0nh \u0111\u01b0\u1ee3c gi\u1eef d\u01b0\u1edbi m\u1ee9c gi\u1edbi h\u1ea1n ch\u1ea3y c\u1ee7a v\u1eadt li\u1ec7u.<\/p>\n

    Ph\u01b0\u01a1ng ph\u00e1p Strain-Life (E-N)<\/h3>\n

    Ph\u01b0\u01a1ng ph\u00e1p Strain-Life cung c\u1ea5p ph\u00e2n t\u00edch chi ti\u1ebft h\u01a1n b\u1eb1ng c\u00e1ch t\u1eadp trung v\u00e0o bi\u1ebfn d\u1ea1ng c\u1ee5c b\u1ed9 t\u1ea1i c\u00e1c \u0111i\u1ec3m t\u1eadp trung \u1ee9ng su\u1ea5t, nh\u01b0 r\u00e3nh ho\u1eb7c l\u1ed7. Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y t\u00ednh \u0111\u1ebfn r\u00f5 r\u00e0ng s\u1ef1 bi\u1ebfn d\u1ea1ng d\u1ebbo x\u1ea3y ra \u1edf c\u00e1c v\u00f9ng c\u1ee5c b\u1ed9 n\u00e0y, ngay c\u1ea3 khi ph\u1ea7n l\u1edbn b\u1ed9 ph\u1eadn v\u1eabn c\u00f2n \u0111\u00e0n h\u1ed3i. \u0110\u00e2y l\u00e0 ph\u01b0\u01a1ng ph\u00e1p \u01b0u ti\u00ean cho ph\u00e2n t\u00edch M\u1ec7t m\u1ecfi chu k\u1ef3 th\u1ea5p (LCF), n\u01a1i bi\u1ebfn d\u1ea1ng d\u1ebbo quan tr\u1ecdng h\u01a1n. Ph\u01b0\u01a1ng ph\u00e1p E-N chia tu\u1ed5i th\u1ecd th\u00e0nh hai giai \u0111o\u1ea1n: b\u1eaft \u0111\u1ea7u v\u1ebft n\u1ee9t v\u00e0 lan truy\u1ec1n v\u1ebft n\u1ee9t. Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y ph\u00f9 h\u1ee3p nh\u1ea5t \u0111\u1ec3 ph\u00e2n t\u00edch tu\u1ed5i th\u1ecd m\u1ec7t m\u1ecfi c\u1ee7a c\u00e1c b\u1ed9 ph\u1eadn c\u00f3 h\u00ecnh d\u1ea1ng ph\u1ee9c t\u1ea1p v\u00e0 t\u1eadp trung \u1ee9ng su\u1ea5t \u0111\u00e1ng k\u1ec3, nh\u01b0 c\u00e1c b\u1ed9 ph\u1eadn c\u00f3 r\u00e3nh, v\u00f2i c\u1ee7a b\u00ecnh ch\u1ecbu \u00e1p l\u1ef1c, ho\u1eb7c c\u00e1c b\u1ed9 ph\u1eadn ch\u1ecbu nhi\u1ec7t \u0111\u1ed9 thay \u0111\u1ed5i d\u1eef d\u1ed9i.<\/p>\n

    \"Thi\u1ebft <\/p>\n

    Ph\u01b0\u01a1ng ph\u00e1p C\u01a1 h\u1ecdc v\u1ebft n\u1ee9t (LEFM)<\/h3>\n

    Ph\u01b0\u01a1ng ph\u00e1p C\u01a1 h\u1ecdc v\u1ebft n\u1ee9t \u0111\u00e0n h\u1ed3i tuy\u1ebfn t\u00ednh (LEFM) c\u00f3 m\u1ed9t g\u00f3c nh\u00ecn ho\u00e0n to\u00e0n kh\u00e1c bi\u1ec7t. Thay v\u00ec d\u1ef1 \u0111o\u00e1n tu\u1ed5i th\u1ecd t\u1ed5ng th\u1ec3 ho\u1eb7c th\u1eddi gian b\u1eaft \u0111\u1ea7u v\u1ebft n\u1ee9t, LEFM gi\u1ea3 \u0111\u1ecbnh r\u1eb1ng v\u1ebft n\u1ee9t ho\u1eb7c l\u1ed7i \u0111\u00e3 t\u1ed3n t\u1ea1i trong v\u1eadt li\u1ec7u t\u1eeb qu\u00e1 tr\u00ecnh s\u1ea3n xu\u1ea5t ho\u1eb7c d\u1ecbch v\u1ee5 tr\u01b0\u1edbc \u0111\u00f3. Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y s\u1eed d\u1ee5ng ph\u1ea1m vi h\u1ec7 s\u1ed1 c\u01b0\u1eddng \u0111\u1ed9 \u1ee9ng su\u1ea5t (\u0394K), m\u1ed9t tham s\u1ed1 m\u00f4 t\u1ea3 tr\u1ea1ng th\u00e1i \u1ee9ng su\u1ea5t t\u1ea1i \u0111\u1ea7u v\u1ebft n\u1ee9t, \u0111\u1ec3 d\u1ef1 \u0111o\u00e1n t\u1ed1c \u0111\u1ed9 t\u0103ng tr\u01b0\u1edfng c\u1ee7a v\u1ebft n\u1ee9t theo chu k\u1ef3 (da\/dN). B\u1eb1ng c\u00e1ch t\u00edch h\u1ee3p t\u1ed1c \u0111\u1ed9 t\u0103ng tr\u01b0\u1edfng n\u00e0y, c\u00e1c k\u1ef9 s\u01b0 c\u00f3 th\u1ec3 d\u1ef1 \u0111o\u00e1n tu\u1ed5i th\u1ecd c\u00f2n l\u1ea1i c\u1ee7a b\u1ed9 ph\u1eadn c\u00f3 l\u1ed7i \u0111\u00e3 bi\u1ebft. Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y l\u00e0 n\u1ec1n t\u1ea3ng c\u1ee7a thi\u1ebft k\u1ebf ch\u1ecbu t\u1ed5n th\u1ea5t h\u01b0 h\u1ecfng, m\u1ed9t tri\u1ebft l\u00fd \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i trong ng\u00e0nh h\u00e0ng kh\u00f4ng v\u00e0 h\u1ea1 t\u1ea7ng. N\u00f3 ph\u00f9 h\u1ee3p nh\u1ea5t \u0111\u1ec3 thi\u1ebft l\u1eadp c\u00e1c kho\u1ea3ng ki\u1ec3m tra cho c\u00e1c c\u1ea5u tr\u00fac quan tr\u1ecdng nh\u01b0 th\u00e2n m\u00e1y bay, c\u1ea7u v\u00e0 c\u00e1c b\u1ed9 ph\u1eadn nh\u00e0 m\u00e1y \u0111i\u1ec7n.<\/p>\n

    So s\u00e1nh ph\u01b0\u01a1ng ph\u00e1p<\/h3>\n

    L\u1ef1a ch\u1ecdn gi\u1eefa ba ph\u01b0\u01a1ng ph\u00e1p m\u1ea1nh m\u1ebd n\u00e0y l\u00e0 m\u1ed9t quy\u1ebft \u0111\u1ecbnh k\u1ef9 thu\u1eadt quan tr\u1ecdng. B\u1ea3ng d\u01b0\u1edbi \u0111\u00e2y t\u00f3m t\u1eaft nh\u1eefng \u0111i\u1ec3m kh\u00e1c bi\u1ec7t ch\u00ednh, \u1ee9ng d\u1ee5ng v\u00e0 gi\u1ea3 \u0111\u1ecbnh c\u01a1 b\u1ea3n c\u1ee7a ch\u00fang \u0111\u1ec3 h\u01b0\u1edbng d\u1eabn qu\u00e1 tr\u00ecnh l\u1ef1a ch\u1ecdn.<\/p>\n

    B\u1ea3ng 1: So s\u00e1nh c\u00e1c ph\u01b0\u01a1ng ph\u00e1p ph\u00e2n t\u00edch m\u1ec7t m\u1ecfi<\/strong><\/p>\n\n\n\n\n\n\n\n\n
    \u0110\u1eb7c \u0111i\u1ec3m<\/td>\nStress-Life (S-N)<\/td>\nStrain-Life (E-N)<\/td>\nC\u01a1 h\u1ecdc v\u1ebft n\u1ee9t (LEFM)<\/td>\n<\/tr>\n
    Tham s\u1ed1 \u0111i\u1ec1u khi\u1ec3n<\/strong><\/td>\nBi\u00ean \u0111\u1ed9 \u1ee9ng su\u1ea5t danh ngh\u0129a (S)<\/td>\nBi\u00ean \u0111\u1ed9 bi\u1ebfn d\u1ea1ng c\u1ee5c b\u1ed9 (\u03b5)<\/td>\nPh\u1ea1m vi h\u1ec7 s\u1ed1 c\u01b0\u1eddng \u0111\u1ed9 \u1ee9ng su\u1ea5t (\u0394K)<\/td>\n<\/tr>\n
    \u1ee8ng d\u1ee5ng ch\u00ednh<\/strong><\/td>\nM\u1ec7t m\u1ecfi chu k\u1ef3 cao (HCF)<\/td>\nM\u1ec7t m\u1ecfi chu k\u1ef3 th\u1ea5p (LCF)<\/td>\nTu\u1ed5i th\u1ecd lan truy\u1ec1n v\u1ebft n\u1ee9t<\/td>\n<\/tr>\n
    Gi\u1ea3 \u0111\u1ecbnh<\/strong><\/td>\nM\u1eabu v\u1eadt nh\u1eb5n, kh\u00f4ng n\u1ee9t<\/td>\nKh\u1edfi ph\u00e1t v\u1ebft n\u1ee9t t\u1ea1i c\u00e1c kh\u00eda<\/td>\nV\u1ebft n\u1ee9t ho\u1eb7c khuy\u1ebft t\u1eadt \u0111\u00e3 c\u00f3 t\u1eeb tr\u01b0\u1edbc<\/td>\n<\/tr>\n
    \u0110\u1ea7u ra<\/strong><\/td>\nT\u1ed5ng tu\u1ed5i th\u1ecd (S\u1ed1 chu k\u1ef3 \u0111\u1ebfn khi h\u1ecfng)<\/td>\nTu\u1ed5i th\u1ecd \u0111\u1ebfn khi kh\u1edfi ph\u00e1t v\u1ebft n\u1ee9t<\/td>\nT\u1ed1c \u0111\u1ed9 ph\u00e1t tri\u1ec3n v\u1ebft n\u1ee9t (da\/dN)<\/td>\n<\/tr>\n
    Tr\u01b0\u1eddng h\u1ee3p s\u1eed d\u1ee5ng l\u00fd t\u01b0\u1edfng<\/strong><\/td>\nThi\u1ebft k\u1ebf tu\u1ed5i th\u1ecd v\u00f4 h\u1ea1n, tr\u1ee5c quay<\/td>\nC\u00e1c b\u1ed9 ph\u1eadn c\u00f3 kh\u00eda, m\u1ecfi nhi\u1ec7t<\/td>\nKh\u1ea3 n\u0103ng ch\u1ecbu h\u01b0 h\u1ecfng, d\u1ef1 \u0111o\u00e1n tu\u1ed5i th\u1ecd<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    C\u00e1ch th\u1ef1c hi\u1ec7n th\u1eed nghi\u1ec7m<\/h2>\n

    Chuy\u1ec3n t\u1eeb c\u00e1c nguy\u00ean t\u1eafc l\u00fd thuy\u1ebft sang \u1ee9ng d\u1ee5ng th\u1ef1c t\u1ebf \u0111\u00f2i h\u1ecfi s\u1ef1 hi\u1ec3u bi\u1ebft r\u00f5 r\u00e0ng v\u1ec1 thi\u1ebft l\u1eadp th\u1eed nghi\u1ec7m. M\u1ed9t th\u1eed nghi\u1ec7m m\u1ecfi th\u00e0nh c\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o m\u00e1y m\u00f3c ch\u00ednh x\u00e1c, c\u00e1c m\u1eabu v\u1eadt \u0111\u01b0\u1ee3c chu\u1ea9n b\u1ecb c\u1ea9n th\u1eadn v\u00e0 quy tr\u00ecnh th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c ki\u1ec3m so\u00e1t ch\u1eb7t ch\u1ebd. M\u1ed7i b\u01b0\u1edbc, t\u1eeb k\u1eb9p m\u1eabu v\u1eadt \u0111\u1ebfn x\u00e1c \u0111\u1ecbnh s\u1ef1 h\u1ecfng h\u00f3c, \u0111\u1ec1u r\u1ea5t quan tr\u1ecdng \u0111\u1ec3 t\u1ea1o ra d\u1eef li\u1ec7u \u0111\u00e1ng tin c\u1eady v\u00e0 c\u00f3 th\u1ec3 l\u1eb7p l\u1ea1i.<\/p>\n

    M\u00e1y th\u1eed nghi\u1ec7m m\u1ecfi<\/h3>\n

    Tr\u00e1i tim c\u1ee7a b\u1ea5t k\u1ef3 ph\u00f2ng th\u00ed nghi\u1ec7m m\u1ecfi n\u00e0o l\u00e0 ch\u00ednh m\u00e1y th\u1eed nghi\u1ec7m. C\u00f3 m\u1ed9t s\u1ed1 lo\u1ea1i, m\u1ed7i lo\u1ea1i ph\u00f9 h\u1ee3p v\u1edbi c\u00e1c \u1ee9ng d\u1ee5ng kh\u00e1c nhau.<\/p>\n