{"id":806,"date":"2016-11-16T10:14:39","date_gmt":"2016-11-16T03:14:39","guid":{"rendered":"http:\/\/vxd.com.vn\/?p=806"},"modified":"2016-11-16T10:24:48","modified_gmt":"2016-11-16T03:24:48","slug":"thiet-ke-cop-pha-co-dinh-khuon-duc-che-tao-tai-cho-bang-go-xe","status":"publish","type":"post","link":"https:\/\/vxd.com.vn\/vi\/thiet-ke-cop-pha-co-dinh-khuon-duc-che-tao-tai-cho-bang-go-xe\/","title":{"rendered":"Thi\u1ebft k\u1ebf c\u1ed1p pha c\u1ed1 \u0111\u1ecbnh (khu\u00f4n \u0111\u00fac ch\u1ebf t\u1ea1o t\u1ea1i ch\u1ed7) b\u1eb1ng g\u1ed7 x\u1ebb"},"content":{"rendered":"

Thi\u1ebft k\u1ebf c\u1ed1p pha c\u1ed1 \u0111\u1ecbnh (khu\u00f4n \u0111\u00fac ch\u1ebf t\u1ea1o t\u1ea1i ch\u1ed7) b\u1eb1ng g\u1ed7 x\u1ebb. V\u00e1n phim<\/h2>\n

B\u1eb1ng c\u00e1c bi\u1ec7n ph\u00e1p c\u1ea5u t\u1ea1o, \u0111\u1ec3 \u0111\u01b0a ra \u0111\u01b0\u1ee3c m\u1ed9t thi\u1ebft k\u1ebf c\u1ed1p pha cho s\u00e0n s\u01b0\u1eddn to\u00e0n kh\u1ed1i c\u00f3 s\u01a1 \u0111\u1ed3 k\u1ebft c\u1ea5u \u0111\u01a1n gi\u1ea3n nh\u1ea5t nh\u01b0ng kh\u1ea3 n\u0103ng ch\u1ecbu l\u1ef1c v\u00e0 ch\u1ed1ng bi\u1ebfn d\u1ea1ng t\u1ed1t nh\u1ea5t c\u00f3 th\u1ec3 (t\u1ed1t nh\u1ea5t l\u00e0 \u0111\u1ec3 k\u1ebft c\u1ea5u c\u1ed1p pha l\u00e0m vi\u1ec7c \u1edf tr\u1ea1ng th\u00e1i \u1ee9ng su\u1ea5t ph\u1eb3ng hay \u1ee9ng su\u1ea5t \u0111\u01a1n). C\u00e1c t\u1ea5m v\u00e1n khu\u00f4n d\u1ea1ng b\u1ea3n n\u00ean \u0111\u01b0\u1ee3c c\u1ea5u t\u1ea1o sao cho l\u00e0m vi\u1ec7c d\u01b0\u1edbi d\u1ea1ng b\u1ea3n d\u1ea7m (b\u1ea3n k\u00ea 2 c\u1ea1nh, l\u00e0m vi\u1ec7c ho\u00e0n to\u00e0n theo tr\u1ea1ng th\u00e1i \u1ee9ng su\u1ea5t ph\u1eafng), k\u00ea tr\u00ean c\u00e1c g\u1ed1i \u0111\u1ee1 d\u1ea1ng thanh ch\u1ecbu u\u1ed1n (tr\u1ea1ng th\u00e1i \u1ee9ng su\u1ea5t ph\u1eb3ng) l\u00e0 c\u00e1c \u0111\u00e0 ngang, gi\u1eb1ng d\u1ecdc, gi\u1eb1ng ngang, g\u00f4ng,.vv.. C\u00e1c g\u1ed1i \u0111\u1ee1 v\u00e1n khu\u00f4n d\u1ea1ng thanh ch\u1ecbu u\u1ed1n n\u00e0y cu\u1ed1i c\u00f9ng truy\u1ec1n l\u1ef1c v\u00e0o c\u00e1c h\u1ec7 thanh ch\u1ecbu k\u00e9o n\u00e9n thu\u1ea7n t\u00fay (tr\u1ea1ng th\u00e1i \u1ee9ng su\u1ea5t \u0111\u01a1n) l\u00e0 gi\u00e1o ch\u1ed1ng (c\u1ed9t ch\u1ed1ng \u0111\u01a1n hay gi\u00e1o t\u1ed5 h\u1ee3p), v\u0103ng ch\u1ed1ng (v\u0103ng ch\u1ed1ng c\u1ee9ng hay d\u00e2y t\u0103ng \u0111\u01a1).<\/p>\n

Ph\u01b0\u01a1ng ph\u00e1p thi\u1ebft k\u1ebf c\u00e1c k\u1ebft c\u1ea5u c\u1ed1p pha d\u1ea1ng d\u1ea7m kh\u00e1c bi\u1ec7t r\u1ea5t l\u1edbn v\u1edbi ph\u01b0\u01a1ng ph\u00e1p thi\u1ebft k\u1ebf c\u00e1c k\u1ebft c\u1ea5u c\u00f4ng tr\u00ecnh, \u1edf ch\u1ed7: s\u1ed1 l\u01b0\u1ee3ng v\u00e0 gi\u00e1 tr\u1ecb kho\u1ea3ng c\u00e1ch c\u1ee7a c\u00e1c nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a k\u1ebft c\u1ea5u c\u1ed1p pha d\u1ea1ng d\u1ea7m l\u00e0 \u1ea9n s\u1ed1 ph\u1ea3i t\u00ecm (th\u01b0\u1eddng kh\u00f4ng bi\u1ebft tr\u01b0\u1edbc), m\u00e0 s\u1ebd ph\u1ea3i \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh qua t\u00ednh to\u00e1n thi\u1ebft k\u1ebf v\u1edbi \u0111\u1eb7c tr\u01b0ng h\u00ecnh h\u1ecdc c\u1ee7a ti\u1ebft di\u1ec7n b\u1ed9 ph\u1eadn c\u1ed1p pha d\u1ea1ng d\u1ea7m \u0111\u01b0\u1ee3c l\u1ef1a ch\u1ecdn tr\u01b0\u1edbc, \u0111i\u1ec1u n\u00e0y l\u00e0 ng\u01b0\u1ee3c v\u1edbi thi\u1ebft k\u1ebf k\u1ebft c\u1ea5u c\u00f4ng tr\u00ecnh.<\/p>\n

\"M\u1eb7t
Thi\u1ebft k\u1ebf c\u1ed1p pha m\u1eb7t b\u1eb1ng c\u1ed1p pha \u00f4 s\u00e0n \u0111i\u1ec3n h\u00ecnh nh\u00e0 nhi\u1ec1u t\u1ea7ng b\u00ea t\u00f4ng c\u1ed1t th\u00e9p to\u00e0n kh\u1ed1i, thi c\u00f4ng theo c\u00f4ng ngh\u1ec7 m\u1ed9t \u0111\u1ee3t tr\u00ean m\u1ed9t t\u1ea7ng.<\/figcaption><\/figure>\n

Thi\u1ebft k\u1ebf h\u1ec7 c\u1ed1p pha s\u00e0n<\/h2>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Thi\u1ebft k\u1ebf v\u00e1n khu\u00f4n s\u00e0n<\/h4>\n

Do ch\u1ee7 \u0111\u1ecbnh thi\u1ebft k\u1ebf v\u00e1n khu\u00f4n s\u00e0n l\u00e0 d\u1ea1ng b\u1ea3n d\u1ea7m, t\u1ee9c l\u00e0 v\u00e1n khu\u00f4n l\u00e0m vi\u1ec7c ho\u00e0n to\u00e0n theo tr\u1ea1ng th\u00e1i \u1ee9ng su\u1ea5t ph\u1eb3ng, n\u00ean c\u00f3 th\u1ec3 c\u1eaft v\u00e1n khu\u00f4n s\u00e0n theo nh\u1eefng ti\u1ebft di\u1ec7n b\u1ea5t k\u1ef3 d\u1ecdc theo ph\u01b0\u01a1ng nh\u1ecbp c\u1ee7a v\u00e1n (l\u00e0 m\u1eb7t c\u1eaft ch\u00ednh c\u00f3 \u1ee9ng su\u1ea5t ch\u00ednh b\u1eb1ng 0) m\u00e0 kh\u00f4ng \u1ea3nh h\u01b0\u1edfng vi\u1ec7c ch\u1ecbu l\u1ef1c v\u00e0 bi\u1ebfn d\u1ea1ng. N\u00ean v\u00e1n khu\u00f4n s\u00e0n c\u00f3 th\u1ec3 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi d\u1ea1ng k\u1ebft c\u1ea5u d\u1ea7m c\u00f3 b\u1ec1 r\u1ed9ng t\u00f9y \u00fd, nh\u01b0ng trong tr\u01b0\u1eddng h\u1ee3p v\u00e1n khu\u00f4n s\u00e0n l\u00e0 g\u1ed7 x\u1ebb, ta c\u00f3 th\u1ec3 quy b\u1ec1 r\u1ed9ng v\u1ec1 gi\u00e1 tr\u1ecb \u0111\u01a1n v\u1ecb (hay l\u00e0 coi t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi m\u1ed9t d\u1ea3i b\u1ea3n (d\u1ea1ng d\u1ea7m) r\u1ed9ng 1 m). Nh\u01b0 th\u1ebf, t\u1ea3i tr\u1ecdng t\u1ed5 h\u1ee3p cho s\u00e0n \u0111\u01b0\u1ee3c quy t\u1eeb ph\u00e2n b\u1ed1 tr\u00ean di\u1ec7n t\u00edch v\u1ec1 ph\u00e2n b\u1ed1 tr\u00ean m\u00e9t d\u00e0i, m\u00e0 v\u1eabn gi\u1eef nguy\u00ean tr\u1ecb s\u1ed1.<\/p>\n

\"Thi\u1ebft
Thi\u1ebft k\u1ebf C\u1ed1p pha c\u1ed9t trong c\u00f4ng ngh\u1ec7 thi c\u00f4ng b\u00ea t\u00f4ng to\u00e0n kh\u1ed1i hai \u0111\u1ee3t ho\u1eb7c ba \u0111\u1ee3t<\/figcaption><\/figure>\n

Ch\u1ecdn tr\u01b0\u1edbc chi\u1ec1u d\u1ea7y lo\u1ea1i v\u00e1n l\u00e0m v\u00e1n khu\u00f4n s\u00e0n \u03b4v, t\u1eeb \u0111\u00f3 x\u00e1c \u0111\u1ecbnh ngay \u0111\u01b0\u1ee3c c\u00e1c \u0111\u1eb7c tr\u01b0ng h\u00ecnh h\u1ecdc c\u1ee7a d\u1ea3i v\u00e1n khu\u00f4n (d\u1ea1ng d\u1ea7m) r\u1ed9ng 1 m, l\u00e0: M\u00f4 men qu\u00e1n t\u00ednh J, m\u00f4 men kh\u00e1ng u\u1ed1n W.<\/p>\n

V\u00e0 do khi c\u1ea5u t\u1ea1o v\u00e1n khu\u00f4n s\u00e0n th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111\u1ec3 nguy\u00ean chi\u1ec1u d\u00e0i t\u1ef1 nhi\u00ean c\u1ee7a t\u1ea5m, m\u00e0 r\u1ea5t h\u1ea1n ch\u1ebf c\u1eaft ng\u1eafn v\u1ee5n ra, \u0111\u1ed3ng th\u1eddi chi\u1ec1u d\u00e0i n\u00e0y th\u01b0\u1eddng l\u1edbn h\u01a1n r\u1ea5t nhi\u1ec1u nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a v\u00e1n khu\u00f4n s\u00e0n khi thi\u1ebft k\u1ebf, n\u00ean v\u00e1n khu\u00f4n s\u00e0n g\u1ed7 x\u1ebb th\u01b0\u1eddng \u0111\u01b0\u1ee3c t\u00ednh to\u00e1n thi\u1ebft k\u1ebf d\u01b0\u1edbi d\u1ea1ng s\u01a1 \u0111\u1ed3 k\u1ebft c\u1ea5u d\u1ea7m si\u00eau t\u0129nh nhi\u1ec1u nh\u1ecbp. C\u0169ng gi\u1ed1ng nh\u01b0 c\u00e1c b\u1ed9 ph\u1eadn k\u1ebft c\u1ea5u c\u1ed1p pha d\u1ea1ng d\u1ea7m kh\u00e1c, s\u1ed1 l\u01b0\u1ee3ng v\u00e0 gi\u00e1 tr\u1ecb c\u1ee7a nh\u1ecbp v\u00e1n khu\u00f4n s\u00e0n \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh sau khi \u0111\u00e3 l\u1ef1a ch\u1ecdn k\u00edch th\u01b0\u1edbc ti\u1ebft di\u1ec7n v\u00e0 \u0111\u1eb7c tr\u01b0ng h\u00ecnh h\u1ecdc c\u1ee7a v\u00e1n khu\u00f4n s\u00e0n. V\u1edbi h\u1ecd d\u1ea7m li\u00ean t\u1ee5c nhi\u1ec1u nh\u1ecbp (d\u1ea7m si\u00eau t\u0129nh nhi\u1ec1u nh\u1ecbp), l\u00e0m vi\u1ec7c theo s\u01a1 \u0111\u1ed3 \u0111\u00e0n h\u1ed3i, th\u00ec n\u1ed9i l\u1ef1c v\u00e0 bi\u1ebfn d\u1ea1ng nguy hi\u1ec3m nh\u1ea5t c\u1ee7a bi\u1ec3u \u0111\u1ed3 bao l\u00e0: (Mmax = q1lv2\/10 (theo th\u00f3i quen cho d\u1ea7m 3 nh\u1ecbp)) ch\u00ednh x\u00e1c l\u00e0 Mmax = q1lv2\/9 (cho d\u1ea7m 4 nh\u1ecbp) v\u00e0 Fmax = q2lv4\/128EJ (cho d\u1ea7m 3 nh\u1ecbp) (trong \u0111\u00f3: q1, q2 l\u00e0 t\u1ed5 h\u1ee3p t\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 tr\u00ean chi\u1ec1u d\u00e0i v\u00e1n khu\u00f4n s\u00e0n l\u1ea7n l\u01b0\u1ee3t t\u01b0\u01a1ng \u1ee9ng v\u1edbi khi t\u00ednh theo \u0111i\u1ec1u ki\u1ec7n c\u01b0\u1eddng \u0111\u1ed9 v\u00e0 \u0111i\u1ec1u ki\u1ec7n bi\u1ebfn d\u1ea1ng).<\/p>\n

T\u00ednh to\u00e1n theo \u0111i\u1ec1u ki\u1ec7n c\u01b0\u1eddng \u0111\u1ed9 (tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n I):
(Mmax\/W \u2264 R) hay R \u2265 (Mmax\/W)
W = (b\u03b4v2)\/6 = (1*\u03b4v2)\/6
Mmax = q1lv2\/9
T\u1eeb \u0111\u00f3, nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a v\u00e1n khu\u00f4n theo \u0111i\u1ec1u ki\u1ec7n c\u01b0\u1eddng \u0111\u1ed9 l\u00e0: lv1 \u2264 {\\displaystyle {\\sqrt {9RW\/q_{1}}}} {\\displaystyle {\\sqrt {9RW\/q_{1}}}} = 3( {\\displaystyle {\\sqrt {RW\/q_{1}}}} {\\displaystyle {\\sqrt {RW\/q_{1}}}}) = 3\u03b4v {\\displaystyle {\\sqrt {R\/6q_{1}}}} {\\displaystyle {\\sqrt {R\/6q_{1}}}}
T\u00ednh to\u00e1n theo \u0111i\u1ec1u ki\u1ec7n bi\u1ebfn d\u1ea1ng (tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n II):
Fmax = q2lv4\/128EJ \u2264 [F] = lv\/400
hay (q2lv3\/128EJ) \u2264 (1\/400)
J = (b\u03b4v3)\/12 = (1*\u03b4v3)\/12
T\u1eeb \u0111\u00f3, nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a v\u00e1n khu\u00f4n theo \u0111i\u1ec1u ki\u1ec7n bi\u1ebfn d\u1ea1ng l\u00e0: lv2 \u2264 {\\displaystyle {\\sqrt[{3}]{128EJ\/400q_{2}}}} {\\displaystyle {\\sqrt[{3}]{128EJ\/400q_{2}}}} = 2( {\\displaystyle {\\sqrt[{3}]{EJ\/25q_{2}}}} {\\displaystyle {\\sqrt[{3}]{EJ\/25q_{2}}}}) = 2\u03b4v {\\displaystyle {\\sqrt[{3}]{E\/300q_{2}}}} {\\displaystyle {\\sqrt[{3}]{E\/300q_{2}}}}
Trong c\u00e1c c\u00f4ng th\u1ee9c tr\u00ean:<\/p>\n

R l\u00e0 c\u01b0\u1eddng \u0111\u1ed9 ch\u1ecbu l\u1ef1c cho ph\u00e9p c\u1ee7a g\u1ed7 t\u1ea5m l\u00e0m v\u00e1n khu\u00f4n s\u00e0n.[F] \u0111\u1ed9 v\u00f5ng cho ph\u00e9p c\u1ee7a k\u1ebft c\u1ea5u c\u1ed1p pha d\u1ea1ng d\u1ea7m.
E m\u00f4 \u0111ul \u0111\u00e0n h\u1ed3i c\u1ee7a g\u1ed7 l\u00e0m c\u1ed1p pha.
q1 t\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 \u0111\u1ec1u tr\u00ean m2 v\u00e1n s\u00e0n, khi t\u00ednh v\u1edbi tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n v\u1ec1 c\u01b0\u1eddng \u0111\u1ed9.
q2 t\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 \u0111\u1ec1u tr\u00ean m2 v\u00e1n s\u00e0n, khi t\u00ednh v\u1edbi tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n v\u1ec1 bi\u1ebfn d\u1ea1ng.
Ch\u1ecdn nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a v\u00e1n khu\u00f4n s\u00e0n l\u00e0 lv \u2264 Min(lv1, lv2) = Min( {\\displaystyle {\\sqrt {9RW\/q_{1}}}} {\\displaystyle {\\sqrt {9RW\/q_{1}}}}, {\\displaystyle {\\sqrt[{3}]{128EJ\/400q_{2}}}} {\\displaystyle {\\sqrt[{3}]{128EJ\/400q_{2}}}}) v\u00e0 kho\u1ea3ng c\u00e1ch th\u00f4ng th\u1ee7y c\u1ee7a \u00f4 s\u00e0n ph\u1ea3i l\u00e0 s\u1ed1 nguy\u00ean l\u1ea7n nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a v\u00e1n s\u00e0n.<\/p>\n

\"M\u1eb7t
M\u1eb7t b\u1eb1ng thi\u1ebft k\u1ebf c\u1ed1p pha s\u00e0n s\u01b0\u1eddn b\u00ea t\u00f4ng to\u00e0n kh\u1ed1i c\u00f4ng ngh\u1ec7 2 \u0111\u1ee3t tr\u00ean t\u1ea7ng<\/figcaption><\/figure>\n

\u00a0 \u00a0 Thi\u1ebft k\u1ebf \u0111\u00e0 ngang \u0111\u1ee1 v\u00e1n s\u00e0n<\/h4>\n

Ch\u1ecdn tr\u01b0\u1edbc ti\u1ebft di\u1ec7n g\u1ed7 x\u1ebb thanh l\u00e0m \u0111\u00e0 ngang \u0111\u1ee1 v\u00e1n khu\u00f4n s\u00e0n nh\u01b0 sau: chi\u1ec1u cao ti\u1ebft di\u1ec7n l\u00e0 hx v\u00e0 b\u1ec1 ngang ti\u1ebft di\u1ec7n l\u00e0 bx, t\u1eeb \u0111\u00f3 x\u00e1c \u0111\u1ecbnh ngay \u0111\u01b0\u1ee3c c\u00e1c \u0111\u1eb7c tr\u01b0ng h\u00ecnh h\u1ecdc kh\u00e1c c\u1ee7a \u0111\u00e0 ngang \u0111\u1ee1 v\u00e1n (d\u1ea7m \u0111\u1ee1 v\u00e1n), l\u00e0: M\u00f4 men qu\u00e1n t\u00ednh Jx, m\u00f4 men kh\u00e1ng u\u1ed1n Wx.<\/p>\n

T\u00ednh to\u00e1n theo \u0111i\u1ec1u ki\u1ec7n c\u01b0\u1eddng \u0111\u1ed9 (tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n I):
(Mmax\/Wx \u2264 R) hay R \u2265 (Mmax\/Wx)
Wx = (bxhx2)\/6
Mmax = Q1lx2\/9 = (lvq1)lx2\/9
T\u1eeb \u0111\u00f3, nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a \u0111\u00e0 ngang \u0111\u1ee1 v\u00e1n khu\u00f4n s\u00e0n theo \u0111i\u1ec1u ki\u1ec7n c\u01b0\u1eddng \u0111\u1ed9 l\u00e0: lx1 \u2264 {\\displaystyle {\\sqrt {9RW_{x}\/Q_{1}}}} {\\displaystyle {\\sqrt {9RW_{x}\/Q_{1}}}} = 3( {\\displaystyle {\\sqrt {RW_{x}\/Q_{1}}}} {\\displaystyle {\\sqrt {RW_{x}\/Q_{1}}}}) = 3hx {\\displaystyle {\\sqrt {Rb_{x}\/6Q_{1}}}} {\\displaystyle {\\sqrt {Rb_{x}\/6Q_{1}}}}
T\u00ednh to\u00e1n theo \u0111i\u1ec1u ki\u1ec7n bi\u1ebfn d\u1ea1ng (tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n II):
Fmax = Q2lx4\/128EJ \u2264 [F] = lx\/400
hay (Q2lx3\/128EJ) \u2264 (1\/400)
Q2 = q2lv
J = ((bxhx3)\/12
T\u1eeb \u0111\u00f3, nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a \u0111\u00e0 ngang \u0111\u1ee1 v\u00e1n khu\u00f4n s\u00e0n theo \u0111i\u1ec1u ki\u1ec7n bi\u1ebfn d\u1ea1ng l\u00e0: lx2 \u2264 {\\displaystyle {\\sqrt[{3}]{128EJ_{x}\/400Q_{2}}}} {\\displaystyle {\\sqrt[{3}]{128EJ_{x}\/400Q_{2}}}} = 2( {\\displaystyle {\\sqrt[{3}]{EJ_{x}\/25Q_{2}}}} {\\displaystyle {\\sqrt[{3}]{EJ_{x}\/25Q_{2}}}}) = 2hx {\\displaystyle {\\sqrt[{3}]{Eb_{x}\/300Q_{2}}}} {\\displaystyle {\\sqrt[{3}]{Eb_{x}\/300Q_{2}}}}
Trong c\u00e1c c\u00f4ng th\u1ee9c tr\u00ean:<\/p>\n

R l\u00e0 c\u01b0\u1eddng \u0111\u1ed9 ch\u1ecbu l\u1ef1c cho ph\u00e9p c\u1ee7a g\u1ed7 thanh l\u00e0m \u0111\u00e0 ngang.[F] \u0111\u1ed9 v\u00f5ng cho ph\u00e9p c\u1ee7a k\u1ebft c\u1ea5u c\u1ed1p pha d\u1ea1ng d\u1ea7m.
E m\u00f4 \u0111ul \u0111\u00e0n h\u1ed3i c\u1ee7a g\u1ed7 l\u00e0m c\u1ed1p pha.
Q1 t\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 \u0111\u1ec1u tr\u00ean \u0111\u00e0 ngang, khi t\u00ednh v\u1edbi tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n v\u1ec1 c\u01b0\u1eddng \u0111\u1ed9.
Q2 t\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 \u0111\u1ec1u tr\u00ean \u0111\u00e0 ngang, khi t\u00ednh v\u1edbi tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n v\u1ec1 bi\u1ebfn d\u1ea1ng.
Ch\u1ecdn nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a \u0111\u00e0 ngang \u0111\u1ee1 v\u00e1n khu\u00f4n s\u00e0n l\u00e0 lx \u2264 Min(lx1, lx2) = Min( {\\displaystyle {\\sqrt {9RW_{x}\/Q_{1}}}} {\\displaystyle {\\sqrt {9RW_{x}\/Q_{1}}}}, {\\displaystyle {\\sqrt[{3}]{128EJ_{x}\/400Q_{2}}}} {\\displaystyle {\\sqrt[{3}]{128EJ_{x}\/400Q_{2}}}}) v\u00e0 chi\u1ec1u d\u00e0i c\u1ee7a \u0111\u00e0 ngang \u0111\u1ee1 v\u00e1n s\u00e0n ph\u1ea3i l\u00e0 s\u1ed1 nguy\u00ean l\u1ea7n nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a \u0111\u00e0 ngang n\u00e0y (t\u1ee9c l\u00e0 kho\u1ea3ng c\u00e1ch c\u1ed9t ch\u1ed1ng s\u00e0n).<\/p>\n

\u00a0 \u00a0Thi\u1ebft k\u1ebf c\u1ed9t ch\u1ed1ng \u0111\u01a1n \u0111\u1ee1 c\u1ed1p pha s\u00e0n<\/h4>\n

T\u1ea3i tr\u1ecdng t\u1eadp trung t\u00e1c \u0111\u1ed9ng v\u00e0o \u0111\u1ea7u c\u1ed9t ch\u1ed1ng<\/p>\n

Pc = qxlx
Ch\u1ecdn c\u1ed9t ch\u1ed1ng b\u1eb1ng g\u1ed7 thanh c\u00f3 ti\u1ebft di\u1ec7n vu\u00f4ng, \u0111\u1ec3 b\u00e1n k\u00ednh qu\u00e1n t\u00ednh c\u1ee7a ti\u1ebft di\u1ec7n theo 2 ph\u01b0\u01a1ng l\u00e0 \u0111\u1ec1u nhau (l\u00e0m \u0111\u1ed9 m\u1ea3nh kh\u00f4ng ph\u1ee5 thu\u1ed9c ph\u01b0\u01a1ng l\u00e0m vi\u1ec7c c\u1ee7a ti\u1ebft di\u1ec7n).<\/p>\n

Momen qu\u00e1n t\u00ednh Jc = (bcbc3)\/12
Di\u1ec7n t\u00edch ti\u1ebft di\u1ec7n Ac
B\u00e1n k\u00ednh qu\u00e1n t\u00ednh rc = {\\displaystyle {\\sqrt {J_{c}\/A_{c}}}} {\\displaystyle {\\sqrt {J_{c}\/A_{c}}}}
S\u01a1 \u0111\u1ed3 k\u1ebft c\u1ea5u c\u1ee7a c\u1ed9t ch\u1ed1ng l\u00e0 d\u1ea1ng thanh ch\u1ecbu n\u00e9n \u0111\u00fang t\u00e2m v\u1edbi 2 \u0111\u1ea7u kh\u1edbp, n\u00ean h\u1ec7 s\u1ed1 li\u00ean k\u1ebft, trong c\u00f4ng th\u1ee9c t\u00ednh chi\u1ec1u cao t\u00ednh to\u00e1n, h\u1ec7 s\u1ed1 li\u00ean k\u1ebft l\u00e0: \u03bc = 1,0. Chi\u1ec1u cao th\u1eadt c\u1ee7a c\u1ed9t ch\u1ed1ng H (l\u00e0 chi\u1ec1u cao l\u00e0m vi\u1ec7c l\u1edbn nh\u1ea5t (l\u00e0 theo ph\u01b0\u01a1ng kh\u00f4ng gi\u1eb1ng), 1 trong 2 ph\u01b0\u01a1ng l\u00e0m vi\u1ec7c c\u1ee7a c\u1ed9t ch\u1ed1ng. Chi\u1ec1u cao l\u00e0m vi\u1ec7c theo ph\u01b0\u01a1ng m\u1eb7t gi\u1eb1ng c\u1ed9t ch\u1ed1ng th\u01b0\u1eddng nh\u1ecf b\u1eb1ng n\u1eeda chi\u1ec1u cao th\u1eadt c\u1ee7a c\u1ed9t ch\u1ed1ng do c\u00f3 l\u1edbp gi\u1eb1ng li\u00ean k\u1ebft). Chi\u1ec1u cao t\u00ednh to\u00e1n l\u00e0 H0max = \u03bcH.<\/p>\n

N\u1ebfu \u0111\u1ed9 m\u1ea3nh \u03bb = H0max\/rc > 75, k\u1ebft c\u1ea5u c\u1ed9t ch\u1ed1ng thu\u1ed9c lo\u1ea1i thanh c\u00f3 \u0111\u1ed9 m\u1ea3nh l\u1edbn. \u0110\u1ec3 \u0111\u1ea3m b\u1ea3o \u0111i\u1ec1u ki\u1ec7n m\u1ea5t \u1ed5n \u0111\u1ecbnh \u0111\u1ed3ng th\u1eddi v\u1edbi m\u1ea5t b\u1ec1n khi thanh l\u00e0 lo\u1ea1i \u0111\u1ed9 m\u1ea3nh l\u1edbn, th\u00ec h\u1ec7 s\u1ed1 u\u1ed1n d\u1ecdc \u03c6 \u0111\u01b0\u1ee3c t\u00ednh theo c\u00f4ng th\u1ee9c:
\u03c6 = 3100\/(\u03bb2)
N\u1ebfu \u0111\u1ed9 m\u1ea3nh \u03bb = H0max\/rc \u2264 75, k\u1ebft c\u1ea5u c\u1ed9t ch\u1ed1ng hay con \u0111\u1ed9i thu\u1ed9c lo\u1ea1i thanh c\u00f3 \u0111\u1ed9 m\u1ea3nh nh\u1ecf. \u0110\u1ec3 \u0111\u1ea3m b\u1ea3o \u0111i\u1ec1u ki\u1ec7n m\u1ea5t \u1ed5n \u0111\u1ecbnh \u0111\u1ed3ng th\u1eddi v\u1edbi m\u1ea5t b\u1ec1n khi thanh l\u00e0 lo\u1ea1i \u0111\u1ed9 m\u1ea3nh nh\u1ecf, th\u00ec h\u1ec7 s\u1ed1 u\u1ed1n d\u1ecdc \u03c6 \u0111\u01b0\u1ee3c t\u00ednh theo c\u00f4ng th\u1ee9c:
\u03c6 = 1 – 0,8(\u03bb2\/100)
Ki\u1ec3m tra c\u1ed9t ch\u1ed1ng s\u00e0n theo \u0111i\u1ec1u ki\u1ec7n v\u1ec1 c\u01b0\u1eddng \u0111\u1ed9 (tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n I):<\/p>\n

\u03c3 = Pc\/(\u03c6A) \u2264 Rn.<\/p>\n

Ki\u1ec3m tra t\u1ed5ng bi\u1ebfn d\u1ea1ng c\u1ee7a c\u1ed1p pha (khu\u00f4n \u0111\u00fac) s\u00e0n<\/h4>\n

Bi\u1ebfn d\u1ea1ng l\u00fan c\u1ed9t ch\u1ed1ng s\u00e0n do t\u1ea3i tr\u1ecdng Pc2 t\u00e1c d\u1ee5ng l\u00e0: \u0394c = (Pc2l)\/(AEg)<\/p>\n

\u0110\u1ed9 v\u00f5ng l\u1edbn nh\u1ea5t c\u1ee7a \u0111\u00e0 ngang \u0111\u1ee1 v\u00e1n khu\u00f4n s\u00e0n l\u00e0: Fmax<\/p>\n

\u0110\u1ed9 v\u00f5ng l\u1edbn nh\u1ea5t c\u1ee7a v\u00e1n khu\u00f4n s\u00e0n l\u00e0: fmax<\/p>\n

T\u1ed5ng bi\u1ebfn d\u1ea1ng tuy\u1ec7t \u0111\u1ed1i c\u1ee7a khu\u00f4n \u0111\u00fac s\u00e0n (k\u1ec3 c\u1ea3 \u0111\u1ed9 v\u00f5ng v\u00e1n khu\u00f4n l\u1edbn nh\u1ea5t, \u0111\u1ed9 v\u00f5ng l\u1edbn nh\u1ea5t c\u1ee7a \u0111\u00e0 ngang \u0111\u1ee1 v\u00e1n v\u00e0 \u0111\u1ed9 l\u00fan ch\u1ed1ng (l\u00fan g\u1ed1i \u0111\u1ee1)) l\u00e0: \u0394cps = \u0394c + Fmax + fmax<\/p>\n

Theo m\u1ee5c c ph\u1ee5 l\u1ee5c A3 ti\u00eau chu\u1ea9n 4453-1995, th\u00ec: “\u0110\u1ed9 v\u00f5ng \u0111\u00e0n h\u1ed3i ho\u1eb7c \u0111\u1ed9 l\u00fan c\u1ee7a g\u1ed7 ch\u1ed1ng c\u1ed1p pha [ph\u1ea3i kh\u00f4ng qu\u00e1]: (1\/1000) nh\u1ecbp t\u1ef1 do c\u1ee7a c\u00e1c k\u1ebft c\u1ea5u b\u00ea t\u00f4ng c\u1ed1t th\u00e9p t\u01b0\u01a1ng \u1ee9ng.” Nh\u01b0 v\u1eady t\u1ed5ng bi\u1ebfn d\u1ea1ng c\u1ee7a khu\u00f4n \u0111\u00fac s\u00e0n ph\u1ea3i \u0111\u01b0\u1ee3c ki\u1ec3m tra theo \u0111i\u1ec1u ki\u1ec7n so s\u00e1nh v\u1edbi nh\u1ecbp c\u1ee7a s\u00e0n theo ph\u01b0\u01a1ng l\u00e0m vi\u1ec7c ch\u00ednh, nh\u01b0 sau: \u0394cps \u2264 Ls.min\/1000<\/p>\n

\u00a0 \u00a0 Thi\u1ebft k\u1ebf h\u1ec7 c\u1ed1p pha d\u1ea7m ph\u1ee5<\/h4>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Thi\u1ebft k\u1ebf v\u00e1n khu\u00f4n \u0111\u00e1y d\u1ea7m ph\u1ee5<\/h5>\n

Ch\u1ecdn tr\u01b0\u1edbc b\u1ec1 d\u00e0y ti\u1ebft di\u1ec7n v\u00e1n g\u1ed7 x\u1ebb l\u00e0m v\u00e1n khu\u00f4n \u0111\u00e1y d\u1ea7m ph\u1ee5 l\u00e0 hv. B\u1ec1 ngang ti\u1ebft di\u1ec7n v\u00e1n khu\u00f4n \u0111\u00e1y d\u1ea7m ph\u1ee5 ch\u00ednh l\u00e0 b\u1ec1 ngang d\u1ea7m ph\u1ee5: bv. T\u1eeb \u0111\u00f3 x\u00e1c \u0111\u1ecbnh ngay \u0111\u01b0\u1ee3c c\u00e1c \u0111\u1eb7c tr\u01b0ng h\u00ecnh h\u1ecdc kh\u00e1c c\u1ee7a v\u00e1n khu\u00f4n \u0111\u00e1y \u0111\u1ea7m ph\u1ee5, l\u00e0: M\u00f4 men qu\u00e1n t\u00ednh Jv, m\u00f4 men kh\u00e1ng u\u1ed1n Wv.<\/p>\n

T\u00ednh to\u00e1n theo \u0111i\u1ec1u ki\u1ec7n c\u01b0\u1eddng \u0111\u1ed9 (tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n I):
(Mmax\/Wv \u2264 R) hay R \u2265 (Mmax\/Wv)
Wv = (bvhv2)\/6
Mmax = Q1lv2\/9
T\u1eeb \u0111\u00f3, nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a v\u00e1n khu\u00f4n \u0111\u00e1y d\u1ea7m ph\u1ee5 theo \u0111i\u1ec1u ki\u1ec7n c\u01b0\u1eddng \u0111\u1ed9 l\u00e0: lv1 \u2264 {\\displaystyle {\\sqrt {9RW_{v}\/Q_{1}}}} {\\displaystyle {\\sqrt {9RW_{v}\/Q_{1}}}} = 3( {\\displaystyle {\\sqrt {RW_{v}\/Q_{1}}}} {\\displaystyle {\\sqrt {RW_{v}\/Q_{1}}}}) = 3hv {\\displaystyle {\\sqrt {Rb_{v}\/6Q_{1}}}} {\\displaystyle {\\sqrt {Rb_{v}\/6Q_{1}}}}
T\u00ednh to\u00e1n theo \u0111i\u1ec1u ki\u1ec7n bi\u1ebfn d\u1ea1ng (tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n II):
Fmax = Q2lv4\/128EJ \u2264 [F] = lv\/400
hay (Q2lv3\/128EJ) \u2264 (1\/400)
J = ((bvhv3)\/12
T\u1eeb \u0111\u00f3, nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a v\u00e1n khu\u00f4n \u0111\u00e1y d\u1ea7m ph\u1ee5 theo \u0111i\u1ec1u ki\u1ec7n bi\u1ebfn d\u1ea1ng l\u00e0: lv2 \u2264 {\\displaystyle {\\sqrt[{3}]{128EJ_{v}\/400Q_{2}}}} {\\displaystyle {\\sqrt[{3}]{128EJ_{v}\/400Q_{2}}}} = 2( {\\displaystyle {\\sqrt[{3}]{EJ_{v}\/25Q_{2}}}} {\\displaystyle {\\sqrt[{3}]{EJ_{v}\/25Q_{2}}}}) = 2hv {\\displaystyle {\\sqrt[{3}]{Eb_{v}\/300Q_{2}}}} {\\displaystyle {\\sqrt[{3}]{Eb_{v}\/300Q_{2}}}}<\/p>\n

Trong c\u00e1c c\u00f4ng th\u1ee9c tr\u00ean:<\/p>\n

R l\u00e0 c\u01b0\u1eddng \u0111\u1ed9 ch\u1ecbu l\u1ef1c cho ph\u00e9p c\u1ee7a g\u1ed7 v\u00e1n l\u00e0m \u0111\u00e1y d\u1ea7m ph\u1ee5.[F] \u0111\u1ed9 v\u00f5ng cho ph\u00e9p c\u1ee7a k\u1ebft c\u1ea5u c\u1ed1p pha d\u1ea1ng d\u1ea7m.
E m\u00f4 \u0111ul \u0111\u00e0n h\u1ed3i c\u1ee7a g\u1ed7 l\u00e0m c\u1ed1p pha.
Q1 t\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 \u0111\u1ec1u tr\u00ean v\u00e1n khu\u00f4n \u0111\u00e1y d\u1ea7m ph\u1ee5, khi t\u00ednh v\u1edbi tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n v\u1ec1 c\u01b0\u1eddng \u0111\u1ed9.
Q2 t\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 \u0111\u1ec1u tr\u00ean v\u00e1n khu\u00f4n \u0111\u00e1y d\u1ea7m ph\u1ee5, khi t\u00ednh v\u1edbi tr\u1ea1ng th\u00e1i gi\u1edbi h\u1ea1n v\u1ec1 bi\u1ebfn d\u1ea1ng.
Ch\u1ecdn nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a \u0111\u00e0 ngang \u0111\u1ee1 v\u00e1n khu\u00f4n s\u00e0n l\u00e0 lv \u2264 Min(lv1, lv2) = Min( {\\displaystyle {\\sqrt {9RW_{v}\/Q_{1}}}} {\\displaystyle {\\sqrt {9RW_{v}\/Q_{1}}}}, {\\displaystyle {\\sqrt[{3}]{128EJ_{v}\/400Q_{2}}}} {\\displaystyle {\\sqrt[{3}]{128EJ_{v}\/400Q_{2}}}}) v\u00e0 chi\u1ec1u d\u00e0i c\u1ee7a tr\u00ean v\u00e1n khu\u00f4n \u0111\u00e1y d\u1ea7m ph\u1ee5 ph\u1ea3i l\u00e0 s\u1ed1 nguy\u00ean l\u1ea7n nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a v\u00e1n khu\u00f4n n\u00e0y (t\u1ee9c l\u00e0 kho\u1ea3ng c\u00e1ch c\u1ed9t ch\u1ed1ng ch\u1eef T \u0111\u1ee1 d\u1ea7m ph\u1ee5).<\/p>\n

\u00a0\u00a0Ki\u1ec3m tra thi\u1ebft k\u1ebf v\u00e1n khu\u00f4n th\u00e0nh d\u1ea7m ph\u1ee5<\/h5>\n

Ch\u1ecdn tr\u01b0\u1edbc b\u1ec1 d\u00e0y v\u00e1n khu\u00f4n th\u00e0nh d\u1ea7m ph\u1ee5. Nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a v\u00e1n khu\u00f4n th\u00e0nh d\u1ea7m ph\u1ee5, \u0111\u00e3 \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh tr\u01b0\u1edbc qua thi\u1ebft k\u1ebf v\u00e1n khu\u00f4n \u0111\u00e1y d\u1ea7m ph\u1ee5, ch\u00ednh l\u00e0 kho\u1ea3ng c\u00e1ch c\u00e1c c\u1ed9t ch\u1ed1ng ch\u1eef T \u0111\u1ee1 d\u1ea7m ph\u1ee5. (V\u00ec \u0111i\u1ec3m g\u1ed1i t\u1ef1a chuy\u1ec1n l\u1ef1c c\u1ee7a t\u1ea5t c\u1ea3 c\u00e1c v\u0103ng ch\u1ed1ng d\u1ea7m ph\u1ee5 ch\u1ec9 c\u00f3 th\u1ec3 l\u00e0 v\u00e0o c\u1ed9t ch\u1ed1ng ch\u1eef T \u0111\u1ee1 d\u1ea7m ph\u1ee5.) Do \u0111\u00f3, vi\u1ec7c thi\u1ebft k\u1ebf v\u00e1n th\u00e0nh d\u1ea7m ph\u1ee5 tr\u1edf th\u00e0nh l\u00e0 vi\u1ec7c ki\u1ec3m tra v\u00e1n th\u00e0nh \u0111\u00e3 ch\u1ecdn v\u1edbi 2 \u0111i\u1ec1u ki\u1ec7n v\u1ec1 c\u01b0\u1eddng \u0111\u00f4 v\u00e0 bi\u1ebfn d\u1ea1ng khi \u0111\u00e3 bi\u1ebft tr\u01b0\u1edbc nh\u1ecbp l\u00e0m vi\u1ec7c c\u1ee7a n\u00f3<\/p>\n

 <\/p>","protected":false},"excerpt":{"rendered":"

Thi\u1ebft k\u1ebf c\u1ed1p pha c\u1ed1 \u0111\u1ecbnh (khu\u00f4n \u0111\u00fac ch\u1ebf t\u1ea1o t\u1ea1i ch\u1ed7) b\u1eb1ng g\u1ed7 x\u1ebb. V\u00e1n phim B\u1eb1ng c\u00e1c bi\u1ec7n ph\u00e1p c\u1ea5u t\u1ea1o, \u0111\u1ec3 \u0111\u01b0a ra \u0111\u01b0\u1ee3c m\u1ed9t thi\u1ebft k\u1ebf c\u1ed1p pha cho s\u00e0n s\u01b0\u1eddn to\u00e0n kh\u1ed1i c\u00f3 s\u01a1 \u0111\u1ed3 k\u1ebft c\u1ea5u \u0111\u01a1n gi\u1ea3n nh\u1ea5t nh\u01b0ng kh\u1ea3 n\u0103ng ch\u1ecbu l\u1ef1c v\u00e0 ch\u1ed1ng bi\u1ebfn d\u1ea1ng t\u1ed1t […]\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[59],"tags":[],"_links":{"self":[{"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/posts\/806"}],"collection":[{"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/comments?post=806"}],"version-history":[{"count":2,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/posts\/806\/revisions"}],"predecessor-version":[{"id":808,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/posts\/806\/revisions\/808"}],"wp:attachment":[{"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/media?parent=806"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/categories?post=806"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/tags?post=806"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}