TINH TOAN KIEM NGHIEM TUOI BEN MOI KET CAU KHUNG GIA CHUYEN H I / 6 N G DAU MAY D13E
SET DUNG TRONG NGANH D U O N G SAT VIET NAM
B O D U C TUAN NGUYEN D i i c TOAN Bgmdn Dau mdy - Toa xe Trtr&ng Dgi hoc Giao thong Van Idi
Tdm idt: Bai bao trinh bay co sa ly thuyet ciia mot phuang phdp ddnh gid tuoi ben mdi, qud trinh tinh todn vd kit qud tinh todn kiem nghiem tuoi ben moi khung gid chuyen hirang ddu mdy DUE dang sir dyng trong ngdnh duang sdt Viel Nam. Qud Irinh tinh loan duac dua tren cdc thong so ddu vao thong qua cdc thir nghiem ldi trong va thu nghiem moi, bao gom dgc tmng ca hgc, dgc trung moi cua vgt lieu, pho toe dp cua ddu mdy tren khu dogn khdo sdt. mdi quan he giua sai (ech binh phuang Irung binh cua bien do ung sudt dong vai tdc do cua dau mdy
Summary: The paper presents the theoretical basis of a fatigue life evaluation method, the calculation process and calculated results of the fatigue life ofthe D13E locomotive bogie frame which is used in Vietnam railways. The calculation process is based on input parameters through the load testing and the fatigue testing. The parameters include mechanical characteristics, fatigue characteristics ofthe material, (he speed spectrum ofthe locomotive on the surveyed section, the relationship between the mean square deviation ofthe dynamic stress amplitude and the locomotive speed
I. D A T \ AN D E
Nhu da biet, hien nay c6 nhieu phuong phap danh gia tuoi ben moi cua ket cau va chi tiet may. Moi phucmg phap deu co nhirng mi nhupc diem nhat dinh va doi hoi cac thong so dau vao thong qua nhiing thi nghiem khac nhau. Can cir nhirng thi nghiem da thyc hien dugc doi vai khung gia chuyen huong (KGCH) dau may D13E trong dieu kien Viet Nam nhu: thanh phan hoa hpc, dac trung ca hpc, dac trung moi ciia vat lieu; cac thu nghiem ve tai trpng tmh va tai trong dpng nham xac dinh pho toe dp cua dSu may tren khu doan khao sat, ham mat dp phan bo bien dp ung suat dpng lan nhat tai cac diem xung yeu tren khung gia chuyen huang, moi quan he giua sai lech binh phuang trung binh cua bien do ung suSt dpng ldn nhat vai toe do van hanh cua dau may v.v..., thay rang co the lua chpn phuong phap danh gia tuoi ben moi dua tren nguyen ly tich luy t6n thucmg moi tuyen tinh do cac nha khoa hgc Lien bang Nga dk xuat [2], [3]. Duai day trinh bay torn XU cac bieu thuc tinh toan ciia phuong phap nay.
Ii. BIEU THUC TINH TOAN
Theo [2], [3], bieu thuc tinh toan kiem nghiem tuoi ben moi k€t cau khung gia chuyen hucmg dau may, toa xe co dang nhu sau:
Tap chi KHOA HOC GIAO THONG V^N TAI S6 47 - 08/2015 3
Trong do; o.,^ - gia trj gioi lian moi ciia lijt cju, MPa; m - chi sfi mu cua duong cong moi, duoc xac dinh thong qua thi nghiem moi, 0 - lie s6 cua ham luy thira mo ta inoi quan he gifta sai lech binh phirong trung binh ciia irng sujt dong voi tdc do ci'ia dau may (hay doan tau).
S . = 0 . v ' (2) Voi: S, - sai lech binh phuong trung binh ciia ung suit dong, MPa; v - toe dp cua dau may
(hay doan tau), km/h; r - chi so mu cua ham luy thira mo ta m6i quan he giua sai lech binh phucmg trung binh cua irng suit dpng voi toe dp eiia dau may (hay doan tau).
C - hang so, dupc tinh toan bang bieu thirc;
3 6 0 0 . 2 ' - . n , . r ( ' ^ ] f . t p , ( v , ) . v r '
C ^ ^ ^ '- (3) No tPc
Vdi: IIL - he so dir trir theo tu6i bSn: r { * ) - ham gamma; f^ - tan so thay doi irng suat dong, Hz; P, ( v J - xac suat xuat hien toe do thii i ciia dau may, toa xe trong qua trinh van dung tren khu doan khao sat; v, - toe dp ciia diu may (hay doan tau), km/h; NQ - so chu trinh ung suat ca so, 9^ - he so dac tnmg cho tinh nhay cam ciia vat lieu doi vdi chu trinh bat doi xirng.
, . = ^ ^ (4)
V6iO|,- gidi han ben cua vat lieu khung gia chuyln hudng. MPa; o, - irng sudt tmh trong ket cau khung gia chuyen hudng, MPa.
He so du tru theo tuoi ben dirge thi hien qua he s6 du trir theo ling suit.
Trong do: ii^ = nin^n^n,, (6) n, - he so xet tdi mire do quan trpng ciia chi tiet. 11,= 1,2; n , - he so xet tdi dp chinh xac
cua cac cong thir tinh toan.
n^ - S,S,S, (7) Vdi: S| = 1,15 - he so xet tdi gia thiet ve phan bo cua cac gia trj ling suat dgng ti'rc thdi theo
luat phan bo chuan; ^ ^^^.
T9P chi KHOA HQC GIAO THONG VAN TAI So 47 - 08/2015
Sj = 1,123 - he so xet tdi cac sai s6 c6 thi xay ra Hen quan tdi viec ling dung gia thuyit tong tich luy tuyen tinh cac ton thuang moi;
S , - 1,10 - he so xet tdi muc do khong chinh xac lien quan tdi viec tinh doi cac dac trung moi tir chu trinh ung suat doi xung sang chu trinh ung suat khong doi xirng;
n^= 1,25 - he so xet tdi miic do chinh xac ciia viec xac dinh cac ung suat dgng khi tinh toan tu6i bin;
n^= 1,25 - he so xet tdi sy chinh xac ciia viec xac dinh gidi ban moi ciia ket cau thuc ciia khung gia chuyen hudng khi tiln hanh cac thir nghiem tren be thir.
Nhu vay, dl ung dung phuang phap da neu cho vice danh gia tudi bin moi ciia ket cSu khung gia chuyen hudng dau may, toa xe trong dieu kien Viet Nam, ta can co cac so lieu thuc nghiem sau day:
- Gidi han chay o^.,,, gidi ban ben o^ cua vat li^u khung gia chuyen hudng;
- Dudng cong mdi ciia vat lieu khung gia chuyen hudng va cac thong so: chu trinh irng suat ca sd Ng, cac gia trj gidi lian moi tuang irng o., , a.,^ va chi so mu m;
- Pho toe dp cua dau may (doan tau) tren khu doan khao sat P, (v, J;
- Ung suat tmh ldn nhat a, tai diem do ciia mat cat xung yeu nhat tren khung gia chuyen hirdng;
- Gia trj bien dp irng suat dOng tai diem do cLia mat cat xung yeu nhat tren khung gia chuyen hudng iing vdi cac khoang toe dg;
- Cac gia tri ky vong a va sai lech binh phuang trung binh S^ciia bien do ling suit dgng tuang irng doi vdi cac khoang toe do;
- Mdi quan he giiJa sai lech binh phuang trung binh cua irng suit dgng vdi cac gia trj toe do cLia dau may (hay doan tau) dudi dang ham luy thira y - ax"" hay S^ = Q.v'
III. CAC THONG SO TINH TOAN
Cac thong so tinh toan hay cac thong so dau vao dugc xac dinh thong qua qua trinh thii nghiem, bao gom:
3.1. Cac dactru-ng cohoe eua vat lieu khung gia chuyen hudng dau may D13E Ket qua thii nghiem dac trung ca hpc cua vat lieu khung gia chuyln hudng dau may Dl 3E nhu sau:
Gidi h^n chay: o.^ = 206,50 MPa;
Tap chi KHOA HOC GIAO THONG VAN TAI S6 47 - 08/2015
Gidi han ben: a. = 311.74 MPa:
Modundanhoi: E= 1,89.10'MPa.
3.2. Cac dac tru-ng nidi ciia vat lieu khung gia chuyen hudng dau may DUE a. Giai hgn moi va chu irinh gi&i hgn moi
Tir cac kit qua thir nghiem moi va cac dudng cong moi da xay dung, ta co:
Khi No = 2.10' thio., = 254.3913 MPa;
Khi No-5.10'' thi a.|= 241,7486 MPa, Khi No = 1.10' thi 0., = 229,4990 MPa
Gidi han moi ciia kit ciu dchu trinh irng suat doi xirng a_it,. (he so 1.25):
Khi No = 2.10'' thi a.i, = 203.5 130 MPa;
Khi Nn = 5.10^ thi o.,^ - 193,3989 MPa;
Khi No = I.IO' t h i o . a = 183,5992 MPa.
h. Ducrng cong moi va chi so mii dircmg cong moi
Tir cac ket qua thir nghiem moi, khi xap xi dudng cong moi ciia vat lieu ket cau thirc cua khung gia chuyen hudng dau may D13E bang phuo'ng trinh ham liiy thira, thong qua phan mem chuyen diing [1] taco cac dudng cong moi (hinh 1 va hinh 2) vdi tham so chi so mii dudng cong moi m= 17,9765= 18.00.
Hinh I. Dirang cong moi dang WeihiiU. Weibull-hga KGCH ddu mdy D/3E DangWeibull N, - 10-"-'-''a;|'"'' hay o^ = 264,382N/'''""'
DangWeibull-loga:igN, -43,5432-]7,97651ga^ hayo^ - 2,4222-0,055628]gN,
Tap chi KHOA HOC GIAO T H O N G VAN TAI So 47 - 08/2015
Hlnh 2. Duang cong moi dgng a^ = aN''. u^= 264,4591 N'"'"^''^'^
vd N = aa"^, N, = 3.49937.10''^a'J,^"^''^ cua vdi li?u KGCH ddu may DUE 3.3. Cac thong so thu nghiem tai trong
a Xdc dinh he so (p^
Vl?c thir nghi?m tai trgng tinh dau may D13E da dugc tiln hanh tai Xi nghiep dau may Sai Con va viec thii nghi?m tai trgng dgng ciia diu may da dugc tien hanh vdi doan tau SNTl/2 tren khu doan Sai Gon - Nha Trang va ngugc lai.
Tir cac kit qua thu nghiem, ta CO iJTig suit tTnh o^ ldn nhit d cac dilm do 14, 15, 17va 19 tren xa dgc va xa ngang khung gia chuyln hudng lin lugt la 18,62; 11,69; 15,4 va 14,748 MPa.
Tir do, ta co h? so dac trung cho tinh nhay cam ciia vat lieu d6i vdi chu trinh bat dii xung ddi vdi cac dilm do lan lugt la:
- B i 6 m d o l 4 ; » , = 5 t l ^ = l i i l Z l l B « = o 94 o, 311,74 -Bilmdol5:<p = H t i l i = 2 i L 7 1 d l l « i = o 9625
o, 311,74 -Di6mdol7;<p = 5 . I S = M Z ± l l M = o 951
o, 311,74 -0i6mdol9;<p , " > - " i - 311,74-14,748 _ ^
"b 311,74
ft. Tan so bien dQ irng suat dong lan nhal lgi cac diim do tren khmg gid cimyin huung dau may DI3E
Tir cac ket qua thil nghi$m tai trpng dpng, thdy i4ng tjn s6 bien dp irng sudt dpng Ion nhdt
Tap chi KHOA HOC GIAO THONG V^N TAI S6 47 - 08/2015
lai cac dilm do tren khung gia chuyln hudng diu may D13E nim trong pham vi tir 0,5 den 5,0 Hz,'mot trong s6 cac dilm do dugc don cu gidi thieu tren hinh 3.
Hinh 3. Pho ldn so hien do ung mdi ddng icii moi so diem do Iren khung gid chuyen huong ddu mii)- DI3E
c. Mdi quan he giita sai lech hinh phuong trung binh ciia hien do irng sudt dgng lav nhal voi tdc do cua dau may
Tir cac kit qua thir nghiem tai trpng dgng. da xac dinh dugc gia tri bien do ling suit dgng tai cac dilm do tren khung gia chuyen hudng dau may D13E tren khu doan khao sat (Sai Gon - Nha Trang - Sai Gon), da xac djnh dugc cac gia trj ky vgng a va sai lech binh phuang trung binh S ciia bien do irng suat dgng dot vdi cac khoang toe do va moi quan he giUa sai lech binh phuong trung binh ciia bien dp irng suat dong ldn nhat ciia cac diem do vdi tdc dp cua dau may
^„ =0.v'(bang I).
Bdng I. Tong hap ket qud xu ly io lieu hien do irng sudt dong a cdc khoang tdc do
T T
1
:
3 4
s
6 7 H
T o r ilo, k m / h
U-IO ia-20 20-30 30.40 4II-S0 50-60 60-70 70-80 H a m l i r o n g
T , I I Itrcmc q u u n
D i ^ m do 14 a, M P a
9,6105 9,6479 10,3191 9 , a i 7 4 11,2505 11,9467 11,6113 11.0039
S , M P a
1.5709 1,6700 2,6794 2,5333 2.8921 2.S7SS 2,1465 3,0-'13 S , ( . p = 1 2 l ' i x ^
R = 0,592
Qlem do 15 a. M P a
11.4544 11,0604 11.2451 10,7292 11,8892 12,9389 11.7478 10,7362 S ^ v | = 1
R = S,. M P a
26791 2,4861 3,5639 2,8865 4,1631 . M l 56 4.2091 3,2643 s : i 9 \ " ' " - "
0,640
D i e m d o 17 J , M P a
9,7945 9,3581 11,1410 9.868 10,9289 11.9018 11,2068 10,6608
S.,, M P a
1,9450 1,5994 1,3626 1,8738 2.2419 2,9998 2.2547 1,8880 . S „ ( \ ) - I . S 7 7 2 v " ' " ' " '
R = 0,867
Die m d o 19 a, M P a
14.2973 15,3882 16,6704 15,9161 17,6740 18,5441 17.6773 17,0287 S J M - R
Sg , MPa
2.3S6J 2.5168 2.6335 1,9819 3,9300 4,5319 J,3145 3,1123 .6595v" " - ' -
= 0,576
Do thi moi quan he giua sai lech binh phuang trung binli ciia bien dp irng suat dpng ldn nhat ciia cac diem do vdi toe dp ciia dau may tren khu doan khao sat dugc xay dyng nhd phan mem chuyen diing [1] va dugc the hien tren hinh 4.
Tap chl KHOA HOC GIAO THONG VAN TAI So 47 - 08/2015
Hinh 4. Do thi moi quan he giita sai lech binh phuang trung binh cita bien dg ung sudi dgng ldn nhdt cua cdc diem do v&i tdc do cua ddu mdy d. Pho toe do cita ddu mdy
Tij cac ket qua thii: nghiem tai trpng dgng, da xac dmh dugc pho toe dp hay xac suat xuat hien cac toe dg thu i ciia dau may tren khu doan da khao sat (Sai Gon - Nha Trang - Sai Gon), dugc cho trong bang 2. Cac thong s6 tinh toan dugc ting hap trong bang 3.
Bdng 2. Xdc sudt xudt hien cdc toe do thu i cua ddu mdy D13E trong qud trinh van dung keo dodn lau SNTl/2 tren tuyen Sdi Gon - Nha Trang - Sdi Gdn Dai tdc dg,
km/h T6C dQ tning binli v„ tim/ti Xic sudt Pi(v,)
0-10 5 0,0281
10-20 15 0,0566
20-30 25 0.0572
30-40 35 0.1023
40-50 45 0.1298
50-60 55 0.1868
60-70 65 0.2525
70-80 75 0.16838
80-90 85 0,0024
Thfing s6 linh todn Chi s6 mu duimp, cong moi, m Tin so bien dO Cmg su^t dpnR f^, Hz H^ s6 nhay cam ciia vai li?u, <p„
H?s6Q Chi so mu r
So chu trinh iJmg suSt ca sa. No Gid trj gicti han moi, a.ib. MPa
Bdng Diem do 14
18 5,0 0,940 1.2358 0,17677 10' 183,6
?. Tong hgp cdc thong sd linh tc khung gid chuyen hudn^
Diem do 15 18 5,0 0.9625 1,8219 0.18641 10' 183,6
Diem do 17 18 5,0 0.951 1,5772 0,08513 10' 183.6
dn ludt ben mdi ddu mdy D13E
Diem do 19 18 5.0 0.9527 1.6595 0.18268 10' 183,6
IV. KET QUA TINH TOAN
Vdi cac thong s6 dau vao da neu d tren, dua theo biSu thuc (!), bSng phan mem chuyen diing [1] da tien hanh tinh toan tuoi ben moi ciia khung gia chuy6n hudng diiu may D13E tuang irng vdi cac diem do xung y6u nhit la 14, 15, 17 va 19. Cac giao dien tinh toan the hien tren hinh 5.
T^p chl KHOA HOC GIAO THONG V^^N TAI S6 47 - 08/2015
Hinh 5. Giao dien tinh todn tuoi ben moi
ciia khung gid chuyen huang ddu mdy D13E lirang irng vai cdc diem do
Qua ket qua tinh toan vdi 4 diem xung yeu nhat, thay rang tudi ben moi cua khung gia chuydn h u d n g dSu may D13E liin lupt la 4,342.10^", 3 , 0 0 0 . 1 0 ' ^ 5 , 3 5 6 . 1 0 " , 2,214 1 0 " kilomet chay, va co the thay tuoi ben moi c6 cac gia tri rat ldn.
V. MOT SO NHAN XET VA KET LUAN
Vdi ket qua tinh toan nhu tren, co the noi ket cau khung gia chuyen hudng dau may D13E CO tuoi ben moi la dai ban, hay noi khac ve mat iy thuyet, no co tuoi ben moi khong han che.
Dieu nay dugc ly giai nhu sau:
- Ket cau khung gia chuyen hudng dau may D13E la thep diic dang hop, chieu day cac tam ket cau tren khung gia d mgt so vi tri c6 kich thudc con Idn han so vdi kich thudc ban ve; dong thdi irng suat ttnh tai cac diem xung yeu la tuong doi nho, khong vugt qua 20 MPa.
- Chi so mil cua dudng cong moi cua vat lieu khung gia chuyen hudng la tuong doi ldn (m= 18)
- Toe do chay tau cho phep theo cong lenh toe do tren khu doan khao sat la khong cao, t6i da la 80 km/h, trong khi t6cdp cau tao ctia d4u may D13E la 110 km/h.
Theo so lieu thong ke tir Xi nghiep dau may Sai Gon, den nay hau h^t cac dSu may D13E da van hanh dugc khoang hon 2.000.000 km, dieu do cung co nghTa la nguy ca xuat hien v^t nut moi tai cac diem xung yeu la chua co kha nang xay ra
Ngay nhan bai lan dau: 10/9/2014 Ngay nhan bai sua: 05/10/2014 Ngay chap nhan dang bai: 11/6/2015 Tai lieu tham khao
[1]. Sguy en Dire Toan. Do Due Tudn {20\3), Xay dirng phSn mgrn danh gia cac chi lieu do tin cay cua ph^n lir va he thdng dau may toa xe tren co sangon ngir lap irinh Madab. D^ tai NCKH, ma s6 T2013-CK-28. Trirong Oai hoc Giao ihong Van lai, Ha Noi.
[2], flysaiiKOB A.M. (1999), HaaeafHOCTb KOHCrpyuHH JIOKOMOTHBOB. M M M T , MocKaa.
[l]. flysauKOB -I ..'7. (2006). HaaeacHOCTb JIOKOMOTHBOB. M M H T , MocKaa*
Phan bien: Le Van Doanh
10 Tap chf KHOA HOC GIAO THONG VAN TAI So 47 - 08/2015