M 影C L影C
2.2.7.C医u t 衣q"x "m ej"vj逢噂 ct 医o"vtqpi"eƒe"vt逢運 ngh 嬰r"8員 c bi羽t
3. Swƒ"vt·pj"8鰻 d‒"v»p
2.2.7.C医u t 衣q"x "m ej"vj逢噂 ct 医o"vtqpi"eƒe"vt逢運 ngh 嬰r"8員 c bi羽t
Vt‒p"8逢運ng c医p I;II , chi隠w"f k"v医m ( c詠 ly gi英c"eƒe"mjg"eq"picpi+"p‒p"ik違o"8院n 5.7o="6.2o="7.2o"v逢挨pi"泳ng v噂i b隠 f {"v医o"3:.42"x "> 44eo"vtqpi"eƒe"vt逢運ng h嬰r"ucw"8吋rj”pi"n¿p"mj»pi"8隠u :
- N隠p"8逸p cao t瑛 3 Ỵ 5m
- Vtqpi"8q衣n chuy吋n ti院p t瑛 n隠p"8逸p sang n隠p"8 q"vt‒p"rj衣m vi chuy吋n ti院p 20 - 40m
Vt‒p"eƒe"8q衣n n隠p"8逸r"swc"x́pi"8医t y院u ho員e"vjcp"d́p"x "p隠p"8逸r"ecq"j挨p"7.2o"" ho員e"eƒe"8q衣n d詠 8qƒp"p隠p"e„"vj吋 n¿p"mj»pi"8隠w"*"n¤p"e壱p"jck"d‒p"e嘘ng, sau m嘘 c亥w"È+"vj·"v医m BTXM c亥p"8逢嬰c b嘘 vt "vj‒o"eƒe"n逢噂i c嘘v"vjfir"v瑛 3.8"8院n 2,3
GVHD:PGS.TS NGUY右N H唄PI"PIåP 44 JXVJ<"Nç"X;P"VJ溢NG Mjk"z¤{"f詠ng m員v"8逢運pi"DVZO"vt‒p"o„pi"eƒv"jq員c c医p ph嘘k"eƒv"u臼k"vj·"荏 ofir" t医m ti院r"z¿e"x噂i l隠 8逢運pi"p‒p"d嘘 tr "jck"vjcpj"vjfir"i運 rjk"34oo0"Ej¿pi"8逢嬰c 8員v"ecq"j挨p"8ƒ{"v医m 5 cm, thanh th泳 nh医v"8員v"eƒej"ofir"v医m 10 cm, thanh th泳 hai 8員v"eƒej"vjcpj"vj泳 nh医v"42"eo"x "8亥u c嘘v"vjfir"8逢嬰e"8員v"eƒej"mjg"picpi"72"eo0
J·pj"4-3.B嘘vt "vj‒o"e嘘v"vjfir
B嘘vt "e嘘v"vjfir"vtqpi"v医m BVZO"8隠rj”pi"p泳v"fq"n¿p"*"E嘘t vjfir"36"d嘘vt "f丑c eƒej"pjcw"522"Ỵ 400 mm; c嘘v"vjfir":"d嘘 vt "picpi"eƒej"pjcw"722"oo="m ej"vj逢噂c m瓜v"n逢噂k"vjfir"n "3622"z"5222"oo"d嘘 vt "jck"n逢噂i trong m瓜t t医o"pj逢"j·pj"x胤
2.3. E挨"u荏n#"vjw{院t c栄a vi羽c n o"ej員t d‒"v»pi"d茨pi"twpi"8瓜ng
Twpi"8瓜pi"8«"8逢嬰c s穎 d映ng r瓜pi"t«k"vtqpi"eƒe"e»pi"vt·pj"z¤{"f詠ng b茨pi"d‒" v»pi"pj逢pi"u詠 hi吋u bi院v"eƒe"n#"vjw{院v""x "e挨"j丑c c栄c"swƒ"vt·pj"twpi"d‒"v»pi"x磯n e”p"ik噂i h衣n nh医v"8鵜nh. Nh英pi"rj¤p"vkej"ucw"pj茨m gi違k"vj ej"eƒe"sw{"nw壱t chung chi ph嘘k"swƒ"vt·pj"twpi"8瓜pi"d‒"v»pi"x "eƒe"nq衣k"rjwqpi"rjƒr"twpi"8瓜pi"mjƒe" nhau.
GVHD:PGS.TS NGUY右N H唄PI"PIåP 45 JXVJ<"Nç"X;P"VJ溢NG
2.3.1. Chuy吋p"8瓜ng rung
Thi院t b鵜 twpi"d‒"v»pi"vj逢運ng ho衣v"8瓜ng d詠c"vt‒p"piw{‒p"n#"fcq"8瓜pi""8k隠w"j”c" j·pj"Ukp."swc{"o瓜t kh嘘k"n逢嬰ng l羽ej"v¤o"swcpj"vt映c.
Fcq"8瓜pi"j·pj"Ukp"8逢嬰e"8鵜pj"pij c"d荏k"e»pi"vj泳c sau : z"?"u"ukp" v"?"u"ukp"4 hv, [8] Vtqpi"8„"<"u"<"Dk‒p"8瓜 ,in (mm) "<""x壱n t嘘e"i„e."tcf1u f : t亥n s嘘, Hz t : th運i gian, s T瑛 rj逢挨pi"vt·pj"p {"vc"e„"< 2 cos 2 os2 x ? r fs r ft ? vc r ft, [8]
Vtqpi" 8„" x" ?" 4 hu" ?" x壱n t嘘c h衣t c詠e" 8衣i trong chuy吋p" 8瓜pi" 8k隠w" j”c." kp1uge" (mm/s) V逢挨pi"v詠vc"e„"< 2 2 4 sin 2 asin2 ft x ? r f s r ft ? r Vtqpi"8„" 2 2 4
a ? r f s = gia t嘘c c詠e"8衣i trong chuy吋p"8瓜pi"8k隠w"j”c."kp1uge2
(mm/s2)
2.3.2. Tham s嘘vtqpi"twpi"8瓜pi"d‒"v»pi
V隠 e挨"d違p."8亥m ch員t v壱t li羽u d衣ng h衣t b茨pi"rj逢挨pi"rjƒr"twpi"8衣v"8逢嬰c b茨ng eƒej"u逸p x院r"eƒe"j衣v"vj»pi"swc"ejw{吋p"8瓜pi."x·"x壱y lo衣i b臼8逢嬰e"oc"uƒv"p瓜k"d‒p" vtqpi0"Pijk‒p"e泳u c栄c"NĨJgtokvg"x "Vqwtpqp"*3;6:+"8«"ej雨 ra r茨pi"oc"uƒv"d‒p"
GVHD:PGS.TS NGUY右N H唄PI"PIåP 46 JXVJ<"Nç"X;P"VJ溢NG vtqpi"d‒"v»pi"v逢挨k"vtqpi"uw嘘v"swƒ"vt·pj"twpi"8瓜pi"n "2037"rui ( 0.001 MPa) so uƒpj"x噂i 3psi (0.02 MPa) 荏 tr衣pi"vjƒk"v pj."x·"x壱{"oc"uƒv"vtqpi"swƒ"vt·pj"twpi" gi違o"8k"8逢嬰c 5% so v噂i tr衣pi"vjƒk"v pj0
J·pj"ucw"ej雨 ra r茨pi"8瓜8亥m ch員v"d‒"v»pi"v逢挨k"d逸v"8亥u 荏 gia t嘘c kho違ng 0.5g (4.9 m/s2). 謂pj"j逢荏ng c栄c"8瓜pfip"ucw"8„"v<pg tuy院p"v pj"x噂i gia t嘘c trong kho違ng 1g t噂k"6i"*;0:"x "5;04 m/s2), ph映 thu瓜e"x q"8瓜 ch員t c栄c"d‒"v»pi0"Swƒ"vt·pj"v<pi"ikc" t嘘e"vj‒o"mj»pi"n o"ikc"v<pi"違pj"j逢荏pi"n‒p"8瓜pfip
Bi吋w"8欝 e pi"ej雨 ra r茨pi"swƒ"vt·pj"v<pi"pjcpj"ikc"v嘘e"e pi"mj»pi"jk羽u qu違 : m瓜t dk‒p"8瓜 nh臼 nh医v"e pi"8逢嬰e"{‒w"e亥w0"ikƒ"vt鵜8„"mjq違ng 0.0015in (0.04mm)
(Kolek -1963)
M嘘k"v逢挨pi"swcp"ik英a gia t嘘e"x "違pj"j逢荏ng c栄a rung r瓜ng cho h厩n h嬰r"d‒"v»pi" ch雨 ra r茨ng k院t qu違 v隠 8瓜 pfip"e„"vj吋8衣v"8逢嬰c trong d違i t亥n s嘘 l噂n gi嘘pi"pj逢"vt‒p" bi吋w"8欝.
J·pj"4-4. Bi吋w"8欝x‒"o嘘k"v逢挨pi"swcp"ik英c"8瓜 b隠p"pfip"e栄c"d‒"v»pi"e泳ng v噂i gia t嘘e"vtqpi"twpi"8瓜ng
GVHD:PGS.TS NGUY右N H唄PI"PIåP 47 JXVJ<"Nç"X;P"VJ溢NG J·pj"4-5. M磯w"vj "pijk羽m v隠 8瓜 b隠p"pfip"x "v雨 tr丑ng c栄c"d‒"v»pi"8逢嬰e"twpi"8瓜ng v噂k"dk‒p"8瓜x "v亥n s嘘mjƒe"pjcw
Trong su嘘v"swƒ"vt·pj"8亥m ch員t b茨pi"twpi"8瓜ng, n<pi"n逢嬰ng truy隠n t噂k"d‒"v»pi" e pi"n "o瓜t tham s嘘 quan tr丑pi"0"P<pi"n逢嬰pi"e„"vj吋8逢嬰e"v pj"vqƒp"vjgq"e»pi"
th泳c sau ( Kirkham Ỵ 1962)
W = c1ms2f3t, [8]
Vtqpi"8„<
GVHD:PGS.TS NGUY右N H唄PI"PIåP 48 JXVJ<"Nç"X;P"VJ溢NG c1 : h茨ng s嘘 ph映 thu瓜e"x q"8瓜 c泳pi"x "8瓜 gi違m ch医n vtqpi"d‒"v»pi
m : kh嘘k"n逢嬰pi"d‒"v»pi"" 2 2 32.2 / s 9.81 / lb kg ft m s à Ơ Ä Õ Å Ư u"<"dk‒p"8瓜, in (mm) f : t亥n s嘘, cpm (Hz) t : th運i gian, s (adsbygoogle = window.adsbygoogle || []).push({});
V„o"n衣k"."{‒w"e亥u c栄a vi羽e"8亥m ch員v"d‒"v»pi"v逢挨k""pj逢"ucw"< - Gia t嘘c nh臼 nh医t cho h厩n h嬰r"d‒"v»pi" e„"oƒe"d·pj"vj逢運ng. - èr"n詠e"8瓜ng nh臼 nh医v"ejq"d‒ v»pi"e„"oƒe"ecq
- Dk‒p"8瓜 rung nh臼 nh医t cho h厩n h嬰p tr瓜n b医t k - P<pi"n逢嬰ng rung nh臼 nh医t cho t医t c違 eƒe"o飲 tr瓜n
2.3.3. S詠 truy隠p"fcq"8瓜pi"u„piswc"d‒"v»pi"v逢挨k
S詠 truy隠p"u„pi"pfip"j·pj"ukpvtqpi"o»k"vt逢運pi"8 p"j欝k"8逢嬰e"v pj"swc"e»pi"vj泳c sau :
Sx = S0 .e- z14 , [8] Vtqpi"8„"<
Sx <"Dk‒p"8瓜 t衣i kho違pi"eƒej"z"v瑛 m瓜v"8k吋m tham chi院w"p挨k"dk‒p"8瓜 n "U0 , in (mm)
"<"H羽 s嘘 v隠8瓜 育m
èr"n詠e"pfip"n噂n nh医t s違p"ukpj"vtqpi"swƒ"vt·pj"f鵜ch chuy吋n c栄c"ik„"v pj"vjgq"e»pi"
GVHD:PGS.TS NGUY右N H唄PI"PIåP 49 JXVJ<"Nç"X;P"VJ溢NG p = v.c.y, [8] Vtqpi"8„"< v : v壱n t嘘c h衣t l噂n nh医t , in/s ( mm/s) c : t嘘e"8瓜u„pi , ft/s (m/s) y : t雨 tr丑ng, lb/ft3 ( kg/m3) èr"n詠c l噂n nh医v"vj·"v雨 l羽 thu壱n v噂i v壱n t嘘c h衣t l噂n nh医t (l亥p"n逢嬰v""8逢嬰c t衣o ra b荏i dk‒p"8瓜x "v亥n s嘘+0"Vjgq"n#"vjw{院t chung v隠 s詠 d鵜ch chuy吋n c栄c"ik„"vtqpi"o»k" vt逢運pi"8 n h欝k"vc"e„"o嘘k"swcp"j‒"ucw< E c f y n ? ? , [8] Vtqpi"8„"<" "<"D逢噂c song, ft (m) f : T亥n s嘘, Hz
G"<"Oqfwn"8 p"j欝k"8瓜ng, psi (MPa).
M瓜t s嘘pijk‒p"e泳w"8«"ej雨 ra nh英pi"ikƒ"vt鵜 mjƒe"pjcw"e栄a t嘘e"8瓜 c栄a u„pi"vtw{隠n vtqpi"d‒"v»pi"v逢挨k0"Vtqpi"uw嘘t ikc"8q衣p"8亥u c栄c"swƒ"vt·pj"twpi."x壱n t嘘e"ik„"x q"
kho違ng 150ft/s (45in/s) (Halken Ỵ 1977). T嘘e"8瓜u„pi"vtw{隠n n茨m trong kho違ng
t瑛 200 t噂i 800 ft/s (60 t噂i 250 in/s) trong kho違ng th運i gian rung t瑛 1 t噂k"4"rj¿v0"" M瓜v"ikƒ"vt鵜 vtwpi"d·pj"722"hv1u"*"372o1u+""x "o瓜t t亥n s嘘 422"J¦"vj·"d逢噂e"uqpi"n " 407hv"*209o+"x "oqfwn"8 p"j欝k"8瓜pi"8逢嬰c thi院t l壱p 荏 m泳c 500 psi (3MPa).
GVHD:PGS.TS NGUY右N H唄PI"PIåP 50 JXVJ<"Nç"X;P"VJ溢NG Rj¤p" v ej" eƒe" vt衣pi" vjƒk"8亥o" mjƒe" pjcw" 8嘘i v噂k"d‒" v»pi" n " o瓜t vi羽c r医t quan tr丑pi0"NĨJgtokvg"x "Vqwtpqp"*3;6:+"8«""ej雨 tc"8逢嬰c s詠 mjƒe"pjcw"t医t l噂n v隠 8員c v pj"e栄c"d‒"v»pi"荏 tr衣pi"vjƒk"v pj"x "vt衣pi"vjƒk"twpi"8瓜ng.
J·pj"4-6. S詠 d鵜ch chuy吋n c栄c"d‒"v»pi"vj»pi"swc"twpi"8瓜ng t瑛 tr衣pi"vjƒk"v pj"v噂i tr衣pi"vjƒk"n臼ng
Swƒ"vt·pj"twpi"d‒"v»pi"p‒p"ejkc"vj pj"eƒe"ikck"8q衣n sau : ikck"8q衣p"8亥w"n "u詠 co pi„v"pjcpj"ej„pi"e栄a h厩n h嬰r"8逢嬰e"8亥o"x "vk院p theo s胤 t噂k"ikck"8q衣n kh穎 oxi vtqpi"d‒"v»pi."Vtqpi"uw嘘v"ikck"8q衣p"e”p"n衣i s詠 rj¤p"v亥pi"d‒"v»pi"u胤 di宇p"tc"."8員c bi羽v"n "eƒe"j厩n h嬰p ch医t l臼ng n院w"swƒ"vt·pj"twpi"8逢嬰e"mfiq"f k"tc"*Mqngz""- 1963).
J·pj"4-7. Vj "pijk羽n ki吋m tra tr荏mjƒpi
Algzcpfgt"*3;99+"8«"pijk‒p"e泳w"swƒ"vt·pj"twpi"d茨ng vi羽e"8q"vt荏 mjƒpi"e挨"j丑c *j·pj"5+0"雲 m泳c th医p c栄c"twpi"8瓜pi."d‒"v»pi"8逢嬰e"8員e"vt逢pi"d荏k"8瓜 c泳pi"x "8瓜 gi違m ch医p0"Mj»pi"e„"v亥n s嘘 c瓜pi"j逢荏pi"p q"8逢嬰e"zƒe"8鵜nh. 雲 m泳e"8瓜 cao c栄a
GVHD:PGS.TS NGUY右N H唄PI"PIåP 51 JXVJ<"Nç"X;P"VJ溢NG twpi"8瓜ng. H羽 s嘘 tr荏 mjƒpi"p茨m trong kho違ng 5 t噂i 10, th医r"j挨p"ikƒ"vt "42"e栄a NĨJgtokvg0 Sau khi chuy吋p"j„c."ejw{吋p"8瓜pi"twpi"8逢嬰c ki吋o"uqƒv"d荏i tr丑ng l詠c v噂i r医v" v"jq員c g亥p"pj逢"mj»pi"d鵜違pj"j逢荏ng b臼k"8瓜 c泳pi"jc{"8瓜 gi違m ch医p."8k隠u n {"ej雨 ra r茨pi"d‒"v»pi"vtqpi"twpi"8瓜ng v壱p"j pj"ik嘘pi"pj逢"ej医t l臼ng. Do mo ogp"n "e違n tr荏 e挨"d違p"8嘘i v噂i chuy吋p"8瓜pi0"A鵜nh lu壱v"KK"Pgyvqp"8逢嬰e"v pj"pj逢" sau: F = ma Vtqpi"8„"<" F : l詠c , lbf (N) m : kh嘘k"n逢嬰ng , 2 ( 2) 32.2 / 9,81 / kg ft s m s
a : gia t嘘c , in/sec2 (mm/sec2)
T瑛 vt‒p"e„"vj吋 kh鰯pi"8鵜nh gia t嘘e"n "j羽 s嘘ej pj"vtqpi"swƒ"vt·pj"8亥m ch員v"d‒"v»pi" b茨pi"twpi"8瓜ng
J·pj"555"o»"v違 3 lo衣i tr衣pi"vjƒk"mjƒe"pjcw"z違y ra trong m瓜v"x k"ik¤{"荏d‒"v»pi" v逢挨k0"A亥w"vk‒p"p院u l詠e"8逢嬰c s穎 d映pi"8吋n o"d‒"v»pi"n逢w"ejw{吋p"o "f逢噂i m泳c {‒w"e亥u , tr荏mjƒpi"u胤vjgq"8逢運ng s嘘 1. Tr荏mjƒpi"e„"vj吋 8逢嬰e"o»"v違 b茨pi"o»" j·pj"8挨p"ik違n t衣o ra b荏i 3 y院u t嘘<"8瓜 c泳ng K, gi違m ch医n C, kh嘘k"n逢嬰ng M. Khi 8逢嬰c k院t n嘘i trong m瓜v"o»"j·pj"fwpi."vt荏mjƒpi"vj·"d茨ng :
Z = C2-"* O"ỴM1 +2
, [8]
N院u l詠e"m ej"vj ej"vj·"8瓜t ng瓜v"v<pi"n‒p"荏 m泳e"ecq"j挨p."8員e"v pj"e挨"j丑e"vjc{"8鰻i x "o»"ogp"vt荏mjƒpi"ik違m xu嘘ng cho t噂i khi v壱t li羽w"vjc{"8鰻i t瑛 tr衣pi"vjƒk"e泳ng sang tr衣pi"vjƒk"n臼ng. Vi羽c gi違o"p {"e栄a tr荏 mjƒpi"o»"v違 b荏k"8逢運ng s嘘 2. Ngay khi l詠e"v<pi"n‒p"p {"8逢嬰e"fw{"vt·, tr荏mjƒpi"u胤 theo v院v"n‒p"zw嘘ng gi嘘pi"8逢運ng ch雨 kh嘘k"n逢嬰pi."x "8逢嬰c ch雨 b荏k"8逢運ng s嘘 3 khi t亥n s嘘mjƒe"pjcw0"Ak隠w"p {"f宇 f pi"jk吋w"8逢嬰c khi tr荏 mjƒpi"vjgq"8逢運ng kh嘘k"n逢嬰ng,t泳e"n "j羽 twpi"8瓜pi"mj»pi"
GVHD:PGS.TS NGUY右N H唄PI"PIåP 52 JXVJ<"Nç"X;P"VJ溢NG e„"ik違m ch医p"x "8瓜 c泳ng K. Ba lo衣k"8逢運ng th鰯pi"p {"<"picpi."pijk‒pi"zw嘘ng d‒p"rj違k."pijk‒pi"n‒p"d‒p"rj違k""8逢嬰e"kp"vt逢噂e"vt‒p"ik医y tr荏mjƒpi"eq"ejq"vc"f宇 f pi"j·pj dung chuy吋p"8瓜pi"e挨"j丑c 8cpi"fk宇n ra.
N院u tr荏mjƒpi"vjgq"o瓜v"vtqpi"eƒe"8逢運ng d嘘e"pijk‒pi"x隠d‒p"rj違i t泳e"n "j羽 rung 8瓜ng thu亥p"8瓜 c泳ng K. N院u tr荏mjƒpi"vjgq"o瓜v"vtqpi"eƒe"8逢運ng ngang t泳e"n "j羽 twpi"8瓜ng thu亥n gi違m ch医n. T医t c違 eƒe"m院t h嬰r"p {"vj·"e„"vj吋x "v医t c違 m丑i h羽 th嘘ng co h丑e"8隠u bao g欝m 3 y院u t嘘 : kh嘘k"n逢嬰pi."nq"zq"x "ik違m ch医n .
Dcejg"*3;95+"8«"8隠 ngh鵜泳ng d映pi"n#"vjw{院v"8瓜ng l詠c h丑c th栄{"mj "f詠c"vt‒p"u詠 di chuy吋n c栄a b丑v"mj "vtqpi"d‒"v»pi"v逢挨k0"Mjw{pj"j逢噂ng c栄c"dqpi"d„pi"fk" chuy吋p"n‒p"vt‒p"rj映 thu瓜e"x q"n詠c n鰻i c栄c"ej¿pi0"E pi"e„"o瓜v"mjw{‒p"j逢噂ng ejq"dqpi"d„pi""8吋 di chuy吋p"n‒p"vt‒p"o瓜t b隠 m員v"8cpi"twpi"jc{"pic{"e違 dich chuy吋n xu嘘pi"f逢噂k0"J挨p"p英c."8瓜 twpi"swƒ"o泳c c栄a c嘘r"rjc"e pi"e亥n ph違i vtƒpj0
Dcej"*3;99+"e¿pi"vj違o lu壱n v隠8瓜鰻p"8鵜nh v隠8瓜 b隠n pfip"e栄c"d‒"v»pi"v逢挨k0"A瓜 b隠p"p {"rj映 thu瓜e"x q"oc"uƒv"p瓜k"."8瓜 k院v"f pj"x "ƒr"n詠c mao d磯n. S穎 d映ng c嘘t li羽w"8逢嬰c nghi隠n v映p"8吋v<pi"oc"uƒv"d‒"vtqpi0"O瓜v"ƒr"n詠c b隠 m員t mao d磯n cao e pi"e„"vj吋8衣v"8逢嬰c b茨pi"eƒej"u穎n "ej¤p"mj»pi"jc{"d荏k"v pj"n詠c h丑e"jc{"ƒr"n詠c 8瓜pi"8逢嬰c t衣o ra trong su嘘v"swƒ"vt·pj"twpi0
GVHD:PGS.TS NGUY右N H唄PI"PIåP 53 JXVJ<"Nç"X;P"VJ溢NG J·pj"4-:0"A逢運ng m嘘i quan h羽 t亥n s嘘."8瓜 c泳ng, tr荏mjƒpi"e挨"j丑c (adsbygoogle = window.adsbygoogle || []).push({});
2.3.5. M泳e"vk‒w"jcq"p<pi"n逢嬰ng
S詠 s映t gi違o"pjcpj"ej„pi"e栄a h厩n h嬰p h嬰p trong su嘘v"swƒ"vt·pj"twpi"e„"vj吋8員c vt逢pi"d荏i bi院n d衣pi"8 p"j欝k"x·"x壱{"{‒w"e亥u m泳e"vk‒w"jcq"p<pi"n逢嬰ng l噂p0"8吋 vi羽c 8亥m ch員v"jq p"vq p"vj·"vq p"d瓜p<pi"n逢嬰pi"8逢嬰c truy隠n s胤 8逢嬰e"vk‒w"vj映 h院t. Trong su嘘t tr衣pi"vjƒk"mj穎qzk"mjk"twpi"."mj»pi"e亥p"vj‒o"p<pi"n逢嬰ng 8吋 gi英 kh嘘i n逢嬰ng chuy吋p"8瓜ng b荏k"x·"j厩n h嬰p 荏 tr衣pi"vjƒk"ik嘘pi"pj逢"ej医t l臼pi"mj»pi"ik違m ch医p0"D‒p"vtqpi"ej医t l臼pi"n#"v逢荏ng, m泳e"vk‒w"jcq"p<pi"n逢嬰pi"fq"twpi"8瓜pi"n " m瓜v"n#"vjw{院v"v逢挨pi"v詠 pj逢"vtqpi"mj»pi"mj 0"O瓜v"n逢嬰ng nh臼oc"uƒv"d‒p"vtqpi"x "
GVHD:PGS.TS NGUY右N H唄PI"PIåP 54 JXVJ<"Nç"X;P"VJ溢NG gi違m ch医n v磯n e”p trong su嘘v"swƒ"vt·pj"mj穎荏zk"x·"x壱{"{‒w"e亥u cung c医p m瓜v" v" p<pi"n逢嬰ng.
2.4. Eƒe"rj逢挨pi"rjƒr"twpi"8瓜ng
T瑛 vt逢噂c t噂k"pc{."eƒe"vj違o lu壱n v隠 twpi"e挨"j丑c ch栄 y院u t壱r"vtwpi"x q"eƒe"sw{" lu壱v"ejwpi"nk‒p"swcp"v噂i 違pj"j逢荏ng c栄c"twpi"8瓜pi"n‒p"h厩p"j挨r"vt瓜p""d‒ v»pi"v逢挨k 0"A嘘i v噂k"eƒe"rj逢挨pi"rjƒr"twpi"mjƒe"pjcw."vq p"d瓜 h羽 th嘘ng rung bao g欝m : thi院t b鵜 rung, h厩n h嬰p tr瓜p"d‒"v»pi"."x "違pj"j逢荏ng c栄a c嘘r"rjc"e pi"rj違k"8逢嬰c pijk‒p"e泳u
2.4.1. Twpi"d‒n trong
M瓜t thi院t b鵜twpi"d‒p"vtqpi"8逢嬰e"pj¿pi"x q"d‒"v»pi"v逢挨k"u胤 s違n sinh ngay ra nh英ng u„pi"pfip"j·pj"vt”p"vw亥p"jq p"*j·pj"+"0"Dk‒p"8瓜 u„pi"ik違m nhanh khi kho違ng t瑛 thi院t b鵜twpi"v<pi0
J·pj"4-9. Piw{‒p"n#"twpi"d‒p"vtqpi
A吋 8衣v"8逢嬰c kho違pi"eƒej"vj ej"j嬰r"vj·"vjk院t b鵜 rung ph違i ho衣v"8瓜ng 荏 e逢運pi"8瓜 rung cao.
GVHD:PGS.TS NGUY右N H唄PI"PIåP 55 JXVJ<"Nç"X;P"VJ溢NG Bergstrom v " Hqtuudncf"8«"8q"8逢嬰c 違pj"j逢荏ng c栄c"twpi"8瓜pi"vt‒p"d隠 m員t c栄a d‒"v»pi0"O嘘i quan h羽 gi英c"dk‒p"8瓜, t亥n s嘘, ph衣m vi 違pj"j逢荏pi"8嘘i v噂i thi院t b鵜 rung trong 荏 60 mm sau 10 t噂k"52"ik¤{"pj逢"j·pj"2-10. Ph衣m vi l噂n nh医t 荏 m瓜t t亥n s嘘 t嘘k"逢w"mjq違ng 200 Hz ( 12000 twpi"8瓜pi"1rj¿v+0
M瓜t t亥n s嘘 t嘘k"逢w"ejq"twpi"vtqpi"8逢嬰e"8q"vtqpi"vj "pijk羽m c栄a Taylor ( 1976) x " Iqnfuvgkp" *3;8:+0" A逢運ng t亥n s嘘 p {" 8逢嬰e" vt·pj" d荏k" Gtuq{" *3;84+" pj逢pi" mj»pi" ej雨 tc" ikƒ" vt鵜 t嘘k" 逢w0" Vtqpi" pijk‒p" e泳w" p {" »pi" u穎 d映ng c嘘p pha 850mmx200mmx200mm."8k隠w"n o"違pj"j逢荏pi"8院n k院t qu違 vj "pijk羽o0"Ak隠w"p {" d宇 d磯p"8院p"ikƒ"vt鵜 gia t嘘c s胤ecq"j挨p"mjk"e嘘p pha l噂p"j挨p0
Pijk‒p"e泳u c栄c"Vq{nqt"8«"ej雨 ra gia t嘘c cho rung trong n茨m trong kho違ng 100 t噂i 200g (980 t噂i 1960 m/s2+"ejq"d‒"v»pi"x噂k"eƒe"e叡 h衣t c嘘t li羽u 38,19,10 mm. V噂k"ikƒ"vt鵜 gia t嘘c cho s印n, thi院t b鵜 rung trong s胤 cho k院t qu違 t嘘k"逢w"荏 dk‒p"8瓜 cao.
J·pj"4-10. Bi吋w"8欝 m嘘k"v逢挨pi"swcp"ik英c"dƒp"m pj"twpi"x噂i t亥n s嘘 x "dk‒p"
8瓜 cho m瓜t thi院t b鵜 rung trong 60 mm
Nh英ng y院u t嘘ucw"n "o嘘k"swcp"v¤o"v噂i rung d‒p"trong:
GVHD:PGS.TS NGUY右N H唄PI"PIåP 56 JXVJ<"Nç"X;P"VJ溢NG ‚ S詠 truy隠p"twpi"8瓜ng t瑛 thi院t b鵜 rung t噂k"d‒"v»pi"v逢挨k
‚ Vi羽c s映t gi違o"p<pi"n逢嬰pi"x "v雨 tr丑ng trong su嘘v"swƒ"vt·pj"vtw{隠p"u„pi"pfip" j·pj"vt”p
‚ 謂pj"j逢荏ng c栄a gi違m ch医p"8嘘i v噂i vi羽c truy隠p"u„pi"vtqpi"d‒"v»pi"v逢挨k Vtqpi"d‒"v»pi"v逢挨k"."dk‒p"8瓜 c栄c"8亥u rung gi違m do s詠 c違n tr荏 c栄c"d‒"v»pi"8嘘i v噂i s詠 di chuy吋p0"Vjgq"n#"vjw{院v"8瓜ng l詠c h丑c , 違pj"j逢荏ng c栄c"f”pi"ej医t l臼ng xung swcpj""vt‒p"vjk院t b鵜twpi""8逢嬰e"8員c trung b荏i ph亥n kh嘘k"n逢嬰pi"vj‒o"i逸p"vt‒p"vjk院t b鵜. Tropi" vt逢運ng h嬰p rung b茨pi" 8亥w" j·pj" vt映, kh嘘k" n逢嬰pi" p {" d茨ng v噂i kh嘘i n逢嬰pi"f”pi"ej医t l臼ng dich chuy吋p"vjgq"Ncod"*3;67+0"Vc"e„"vj吋 v pj"ikc"v嘘c c栄a thi院t b鵜twpi"vtqpi"j·pj"vt映 v噂k"e»pi"vj泳c sau :
2 2 4 e v e b f m r a m m m r ? - - , [8] Vtqpi"8„"<" a : gia t嘘c, in/s2 (mm/s2) f : t亥n s嘘, Hz me : kh嘘i n逢嬰ng kh嘘i l羽ej"v¤o."nd"*mi) t"<"8瓜 l羽ej"v¤o"."kp"*oo+
mv : kh嘘k"n逢嬰ng thi院t b鵜 rung tr瑛8k"mj嘘k"n逢嬰ng l羽ej"v¤o."nd"*mi+ mb : kh嘘k"n逢嬰pi"d‒"v»pi"f鵜ch chuy吋n, lb (kg)
Dk‒p"8瓜 c栄a thi院t b鵜twpi"vtqpi"d‒"v»pi""vj·"u医p x雨 70 t噂k"97"'"dk‒p"8瓜 c栄c""p„" vtqpi"mj»pi"mj "8k隠w"p {"vj吋 hi羽n s詠rj́"j嬰r"ik c"v pj"vqƒp"x "ikƒ"vt鵜8q"*j·pj+
GVHD:PGS.TS NGUY右N H唄PI"PIåP 57 JXVJ<"Nç"X;P"VJ溢NG J·pj"4-11. M嘘i quan h羽 gi英c"d‒p"8瓜x "dƒp"m pj"e栄a thi院t b鵜
L詠e"n{"v¤o"H."vj雨nh tho違pi"8逢嬰c s穎 d映pi"n o"vjco"u嘘 c栄a thi院t b鵜 rung trong, 8逢嬰e"v pj"vjgq"e»pi"vj泳c sau :
2 1 4( ) e F f m r g r ? ,[8] Vtqpi"8„"< F : l詠e"n{"v¤o."ndh"*P+ g : gia t嘘c , ft/s2 (m/s2)
S詠 s映t gi違o"ƒr"n詠e"8逢嬰c sinh ra trong h厩n h嬰p b荏i u„pi"pfip"j·pj"ukp"vtqpi"uw嘘t m瓜t n穎a c栄a chu k . Vi羽e"v<pi"e逢運pi"8瓜 twpi."swƒ"vt·pj"v衣q"tc"j挨k"p逢噂e"x "d丑t mj "icu."8員e"vt逢pi"d荏i tr衣pi"vjƒk"z¤o"vj詠e."e„"vj吋n o"ik違m s詠 dich chuy吋p"p<pi" n逢嬰ng gi英a thi院t b鵜 twpi"x "d‒"v»pi0"Pj英ng b丑v"mj "dqpi"d„pi"p {"ik嘘pi"e„"mj違 p<pi"jq衣v"8瓜ng gi嘘pi"pj逢"d瓜 gi違m ch医p"x "u„pi"pfip"ik違m ch医n. 雲 ƒr"n詠c gi違m 8k."pj英ng b丑v"mj "pj臼 p {"j嬰p nh医v"8隠 t衣q"vj pj"pj英pi"v¿k"n噂p"j挨p"vj泳 e„"vj吋
GVHD:PGS.TS NGUY右N H唄PI"PIåP 58 JXVJ<"Nç"X;P"VJ溢NG th医{"8逢嬰c 荏 thi院t b鵜 twpi"8cpi"jq衣v"8瓜ng 荏 gia t嘘c cao. S詠 z¤o"vj詠c b逸v"8亥u khi dk‒p"8瓜ƒr"n詠c Pc c栄c"u„pi"pfip"8衣t t噂k"ƒr"n詠e"vj ej"j嬰p
Pc@"302"-" ij"Ỵ 0.03, [8] Vtqpi"8„"< "<"v雨 tr丑ng ,lb/ft3 (kg/m3) g : gia t嘘c b荏i tr丑pi"n逢嬰ng (m/s2) j"<"8瓜 u¤w"d‒p"f逢噂i b隠 m員t, ft (m) 2.4.2. Rung b隠 m員t
Thi院t b鵜 rung b隠 m員v"e„"vj吋 n "nq衣k"d p"n "rung 8挨p."8»k."8¤{"n "thi院t b鵜 e„"vj吋 8亥o"u¤w"v噂i 200mm trong l噂r"d‒"v»pi"8 p"j欝i, t亥n s嘘 trong kho違ng 3000 Ỵ 6000 l亥p1rj¿v"*"72"v噂k"322"J¦+"x "ikc"v嘘c t瑛 5 t噂i 10 g.
A嘘i v噂i h厩n h嬰p tr瓜n c泳pi."d p"n "twpi"u胤 n員pi"j挨p"8吋8衣v"8逢嬰e"8瓜pfip"{‒w"e亥u e pi"pj逢"8瓜 u¤w"c亥n thi院v0"A瓜 pfip"rjw"vjw瓜c ch栄 y院w"x q"泳ng su医v"8瓜ng sinh ra vtqpi"d‒"v»pi"x "e„"vj吋 8逢嬰e"v pj"vjgq"Ycn¦"*3;82+ theo
GVHD:PGS.TS NGUY右N H唄PI"PIåP 59 JXVJ<"Nç"X;P"VJ溢NG 永ng su医v"pfip"?"*v違k"vkpj"z"dk‒p"8瓜 x t亥n s嘘 ) / ( t嘘e"8瓜 ch衣y) (adsbygoogle = window.adsbygoogle || []).push({});
Th詠c nghi羽m ch雨 ra r茨ng v噂k"épi gia t嘘c, vi羽c k院t h嬰r"dk‒p"8瓜 cao v噂i t亥n s嘘 th医p cho k院t qu違 t嘘v"j挨p"xk羽c k院t h嬰r"dk‒p"8瓜 th医p v噂i t亥n s嘘 cao.
Eƒe"d p"n "twpi"8逢嬰c s穎 d映pi"vt‒p"n噂r"d‒"v»pi"f {"vj逢運pi"e„"ejk隠u r瓜ng nh臼 nh医v"e„"vj吋 8吋8衣v"8逢嬰e"8瓜u¤w"違pj"j逢荏ng c亥n thi院t.
Vi羽c s穎 d映ng thi院t b鵜 8亥o"n "eqp"n<p"swc{"8嘘i v噂i h厩n h嬰r"d‒"v»pi"mj» e pi"8«" 8逢嬰c s穎 d映ng nhi隠w"pj逢pi"8”k"j臼i t雨 l羽 h厩n h嬰p tr瓜n ph違k"8ƒr"泳pi"8逢嬰e"{‒w"e亥u k悦 thu壱v"8隠 ra. N院u m瓜t h厩n h嬰p tr瓜n swƒ"mj» vj·"xk羽e"8亥m s胤 mj»pi"8衣t hi羽u qu違 ecq."e”p"d‒"v»pi"o "swƒ"育o"逢噂i s胤 n o"ejq"eqp"n<p"vt荏n‒p"x医{"d́p"vtqpi"d‒" v»pi"v逢挨k0
Thi院t b鵜 8亥m b茨pi"eqp"n<p"swc{"d鵜違pj"j逢荏ng b荏k"eƒe"{院u t嘘 sau : t雨 l羽 h厩n h嬰p tr瓜n, chi隠w"u¤w"8亥m, t嘘e"8瓜 cop"n<p quay."piq k"tc"kh嘘i n逢嬰ng b違n vj¤p eqp"n<p" e pi"t医t quan tr丑pi."vj逢運ng trong ph衣m vi kho違ng 4500 t噂i 5500 kg v噂i t亥n s嘘
rung 1500 t噂i 2500 rung 8瓜ng 1rj¿v"*47"v噂i 42 Hz)
2.4.3. Rung c嘘p pha
Trong rung c嘘r"rjc."8k隠u thi院t y院w"n "u詠 rj¤p"d嘘 rung ph違k"8欝ng nh医v"vt‒p"vq p" b瓜 c嘘r"rjc0"Dk‒p"8瓜 ph違k"v逢挨pi"8嘘k"8欝pi"8隠w"zw{‒p"uw嘘t c違 b隠 m員v0"Ak隠w"p {"t衣o ra kho違pi"eƒej"n噂n nh医t t瑛 1.5 t噂k"407o"8嘘i v噂k"eƒe"vjk院t b鵜 rung. Gia t嘘c rung nh臼 nh医v"dcp"8亥u cho c嘘r"rjc"n "v瑛 1 t噂i 3 g (9.8 t噂i 10m/s2) cho t噂i khi c嘘p pha 8k隠p"8亥{"d‒"v»pi"vj·"ikc"v嘘c t瑛 5 t噂i 10 g ( 49 t噂i 98 m/s2) (Forssblad 1971).
GVHD:PGS.TS NGUY右N H唄PI"PIåP 60 JXVJ<"Nç"X;P"VJ溢NG J·pj"4-13. Piw{‒p"n#"twpi"e嘘p pha
Dk‒p"8瓜 s胤 v<pi"f亥n theo kho違pi"eƒej"z"v瑛 t医m c嘘r"rjc"twpi"x "vjgq"e»pi"vj泳c sau :
Sx = S0 e-* 14+z,[8]
S0<"Dk‒p"8瓜荏 c嘘p pha, in (mm)
T亥n s嘘 vj ej"j嬰p cho c嘘p pha rung ph映 thu瓜e"x q"m ej"e叡 x ""vjk院t k院 c栄a c嘘p pha0"X·"x壱y vi羽c ch丑n thi院t k院 c栄a c嘘p pha rung 荏 t亥n s嘘 th医p hay t亥n s嘘 ecq"vj·" quan tr丑pi"j挨p"n "nq衣k"d‒"v»pi"u胤8逢嬰e"pfip"vtqpi"e嘘p pha. Rung c嘘p pha c栄a h厩n h嬰r"mj»"{‒w"e亥u k院t h嬰r"dk‒p"8瓜 ecq"x "v亥n s嘘 th医p. Ph映 thu瓜e"x q"8k隠u ki羽n c映
th吋, t亥n s嘘 rung n茨m trong kho違ng 3000 t噂i 12000 rung 8瓜ng1rj¿v"*"72"v噂i 200
GVHD:PGS.TS NGUY右N H唄PI"PIåP 61 JXVJ<"Nç"X;P"VJ溢NG m員t t嘘v"j挨p"n "荏 t亥n s嘘 th医p *j·pj2-14)0"Ak隠w"p {"f宇f pi"jk吋w"8逢嬰c b荏i 荏 t亥n s嘘 cao s胤 t衣o ra hi羽u 泳pi"d挨o"n噂p"j挨p"vt‒p"eƒe"j衣t m鵜p"vtqpi"d‒"v»pi"v逢挨k0"Vj泳 s胤 iqo"eƒe"j衣t c嘘t li羽u m鵜p"vt‒p"d隠 m員t c栄a c嘘p pha.
J·pj"4-14. S嘘 b丑v"mj "vt‒p"d隠 m員v"d‒"v»pi"8衣v"8逢嬰c b荏i rung c嘘p pha 荏 nh英ng t亥n s嘘mjƒe"pjcw0
2.4.4. D p"twpi
Lo衣k"twpi"p {"vj·"8瓜 鰻p"8鵜nh mfio"x "mj„"ik違k"vj ej"j挨p"eƒe"nq衣i ti院p"vt·pj"twpi" mjƒe0"Vt‒p"o瓜v"d p"twpi."e嘘r"rjc"épi"x噂k"d‒"v»pi""vtqpi"e嘘r"rjc"e„"vj吋 d鵜ch chuy吋p"mjƒ"n "v詠 do trong su嘘v"swƒ"vt·pj"twpi"x "u詠 c瓜pi"j逢荏pi"e„"vj吋 x違y ra. X "e pi"rj違p"ƒpj"u„pi"ƒr"n詠e"v逢挨ng ph違n v噂i b隠 m員v"d‒"v»pi"n o"違pj"j逢荏ng t噂i s詠rj¤p"d嘘 dk‒p"8瓜."x "n#"fq"p {"vj·"vj逢運ng b医t quy t逸c (Desov 1971) .
GVHD:PGS.TS NGUY右N H唄PI"PIåP 62 JXVJ<"Nç"X;P"VJ溢NG A瓜 pfip"e栄c"d‒"v»pi"違pj"j逢荏ng b荏i gia t嘘c c栄c"d p0"Ikc"v嘘e"p {"mjq違ng 5 t噂i 10 g (49 t噂i 98 m/s2) n¿e"8亥w"x "ucw"8„"n "mjq違ng 2 t噂i 4 g (20 t噂i 39m/s2) trong su嘘t swƒ"vt·pj"twpi0"V亥n s嘘 rung t嘘k"逢w"n "mjq違ng 3000 t噂k"8222"twpi1rj¿v"*72" t噂k"322J¦+0"Dk‒p"8瓜 l噂p"vj·"e亥n thi院v"ejq"8亥m ch員t hi羽u qu違 x "pjcpj0"雲 épi"