Nghiên cứu phương pháp kiểm tra độ bền chung sử dụng trong bài toán tối ưu hóa kết cấu tàu vỏ thép

Tgp chi Khoa hoc - Cong ngh^ Thuy sdn So 3/201 THONG BAO KHOA HOC NGHIEN ClTU PHl/ONG PHAP KIEM TRA DO BEN CHUNG SU^ DUNG TRONG BAI TOAN TOI U*U HOA KET CAU TAU VO THEP THEAPROACH VERIFIED AN ULTIMATE LONGITUDINAL STRENGTH FOR APPLIED TO STRUCTURAL OPTIMIZATION OF STEEL SHIP Phqm Bd Linh' Ngiy nhln bai: 28/3/2014; NgJy phan bien thong qua: 05/5/2014; Ngay duyel dang- 13/8/2014 TOM TAT Bdi bdo cong bo thuat todn cua chuang trinh linh todn ben chung ldu vo thep du&i tdc dtfng ctia mo men uon doc theo phuang phdp Smith su dung bdi loan lot uu hoa kit cau tdu vo thep Dp tin cgy cua chuang trinh dugc chung minh bang cdch SO sdnh vai cdc kit qud ihuc nghidm tren mo hinh gan dung da dugc cong bo cua cdc nghien cuu khac tren the gioi Chuong Irinh dugc dp difng tinh todn ben chung, bdt todn tai uu hoa kit cdu, cua Idu hang rai 2000 D WT dong tai Nhd may Dong tdu Nha Trang Tirkhoa: dg ben chung, mo men uon dgc, phuangphdp Smith ABSTRACT This paper publish the program lo generated the ultimate longitudinal strength of steel ship under vertical bending moment according to Smith method for applied to structural optimization The reliability of this program demontraled by comparison the result with many experiment models which published on the world The program applied to calculate the ultimate longitudinal strength, in structural optimum problem, of bulk carrier 2000 DWT was built at Nha Trang Shipyard Keywords: ultimate longitudinal strength, vertical bending moment Smith method i DAT V A N D £ Trong bai toan toi uu hda k i t cau tdu vd thep, vific danh gid muc dd thda man di4u kifin toi uu theo ^- nhidu ^ phuong ^ • chdng hgn nhu bp thdng so^ rat dn, kfit cau sau t6i uu cd thoa man dieu kifin dg ben on dinh, hinh hgc , dd phuang dn thda man dieu Kifin dp b4n chung dudi tdc dgng ciia mfi men J '^ , ' , " ,.* - "a " n •uon dgc tau la quan trgng nhdt va dugc Quy phgm quy ainh [3] Da co nhilu phirang phap tinh dp b i n Chung ciJa & v6 thep dudi tac dung cua m6 men u6n doc, nhien phi/ang phap Smith (4], [7] d w c SLP dung nhilu hon ca t)*i tinh u'u viet cija n6 va da duoc Quy pham lACS [8] iJng dung Bai b^o xay dung chuong trinh tinh b i n chung tSu vo thep theo phucmg phap Smith va si> dung n6 d l kilm tra dilu ki#n rSng bupc cua bp thdng s6 kit cau, n l u dO ben chung cua tau theo bp thong so kit cau (tinh theo phuong phap cua bai bao nay) khdng dugc thoa man theo dieu kifin quy pham, &ii nd khong dugc chap nhdn vd ngugc Igi [9] .,„,_ ^ L» ^ • L1 Khai mem ben Chung tau vo thep Ket cdu vd tdu thuy (sau day gpi chung Id vd tdu) Id mfit hfi thfing ket cau tam gia cudng phipc tap bao gom nhieu phan nhu kit cdu boong, day, man, vdch ngan, sudn vd gia cudng theo 7- s- » ^ _ , * P''''""9 ="= ' ^ " ' • '"°'^ ^'^ '"^" ^'^" ""^'^ """= "" >^"3 •'°= 1^" """"^ • * " " ' " " " " ^ " S ' ^^ ^" ^ * ! " 6.iAii< / 1^ \' II 061 TU'ONG VA PHU'O'NG P H A P NGHlfiN CI>U Ddi tugng nghien cuu B l i tugng nghifin ci>u Id chuang trinh kilm tra dfi bin chung tau v6 thdp theo phuang phdp Smith, ung dgng cho tdu chd hang rdi 2000 DWT Nhd mdy Odng tdu Nha Trang sdn xult ndm 2001 [2] theo quy phgm phdn cap vd ddng tdu bien vd thfip TCVN 6259:1997 vd dugc Ddng kilm Vifit Nam kilm duyfit Phuo'ng phdp nghien ciru Rit nhilu cfing trinh nghifin euu da cdng bo v l vific ddnh gid dfi bin chung ciia tdu bang phuang phap Smith, vd hifin T chue Dang kilm lACS (Intemational Association of Classification Societies) [8] dd dua vdo quy phgm each xde djnh dp bin chung cua tdu theo phuang phdp Do vdy, d ddy trinh bdy eg the phuang phdp Smith de xde djnh dfi ben chung cOa tau - Phdn chia mgt edt ngang ciJa tdu nhdng phan tir bao gom n?p gia cudng c6 lifin k i t vdi tfin tam (hinh 2) ' AJ->Ai,y y ardnglbeo -II -' a (3 vj tri m ^ v^ boong b d vj tri v^ch dgc Hinh Vi dy ve vifc pha n chia cic phan ta - Tdng d i n dfi cong cua vd tdu vdi gid su rang mat cdt ngang cdn phang vd hifin tugng ufin xay doi vdi trye trung hda hifin t^l cCia mgt cat ngang dd - Xac djnh dfi ben dgc tnjc cua cdc phin tip ket c l u rifing bifit (irng suit ciia phin tir dugc suy tir biln dgng) dga tren moi quan hd ung suat trung binh vd biln dgng trung binh - Xdc djnh dp ben u6n cua mgt eit ngang bing tich phan t i t ca dfi ben dpe true cua cdc phin td k i t d u Moi quan hfi tdng d i n giua dp cong vd mfi men u l n la tdng cdc gia trj dugc tich luy ndy Gid tri dfl b i n chung (hogc md men uon chung hogc Id md men uon tdi hgn) M^J duge djnh nghJg Id gid trj eao nhit cua dudng eong giOa md men uon dgc M va cong k (hodc gdc xoay q) cua mdt d t ngang vd tdu Gid trj md men u l n M, tdc dfing vao mgt cat ngang vfi tdu theo dp cong /f, dugc tinh cho tCrng budc tdng d i n ciia todn bfi qud trinh Dfi cong ndy dugc suy dua theo gdc xoay eua mgt d t ngang vd tdu theo trgc trung hda, nd Id nguyen nhan gdy bien dgng dpc tnic £ mdi phin tir kit c l u Trong dleu kifin tau dudi ddy sdng, phin tip kit c l u phia dudi trye trung hda se bj keo, dd nhu'ng phin tu phia tren tnjc trung hda se bj ndn Gid tri uii\g suit a mdi phan tu k i t c l u dugc suy bdng biln dgng c tir dudng eong irng suit trung binh vd biln dgng trung binh o-e eua mfii phan tip, dd Id hifin tugng xdy miln ddn h l i • ddo ciia m5i phin tu k i t d u Khi biln dgng ciia phin tCr Id kdo thi quan hfi giira irng suit trung binh vd biln dgng trung binh dugc xem Id dan hfii vd hoan todn dfio Tuy nhifin, quan hfi biln dgng bj nfin thi cgc kJ phirc tgp Mil quan hfi bit d i u tir khdi d i u dudng thing, d i n gid trj Idn nhit (irng suit tdi hgn, ultimate strength) thi nhd han irng suit chdy Sau dgt dugc dllm tdi hgn, chang han viing sau gia trj tdi hgn, th) irng suit se giam (hinh 3) TRLTONG OAI HOC NHA TRANG • 39 So 3/2014 Tgp chi Khoa hoc - Cong nghe Thuy sdn Vtoflif>taH'c*itf« VbibiUaMcfilalUy Hinh Quan h$ ihig suat trung binh vk hi^n d^ng trung binh cua phin tir iy g6c |4] Hinh Quan h^ irng suit trung binh vii b)£n dang trung binh cua ph^n tfr ttadng thiTbng [4| E)6i vdi cdc phin tir d gdc (hard comer element), mii quan hfi giCra irng suit trung binh vd biln dgng trung binh duge xem Id ddn hoi vd hodn todn deo trfin d hai dgng keo vd nfin (nhu hinh 4) Khi nfii lue cua m i i phin tu kit d u dugc xdc djnh bang irng suit trfin dien tich cOa nd (bao gom difin tich mat d t ngang ciia ngp gia cudng vd tfin t i m dinh kem) vd ting cdc ndl lgc ndy chinh Id tong Igc dpc tn,ic tren mdt d t ngang Ting nfii luc ndy cd t h l bang khdng tgi trgc trung hda hifin tgi hodc thay d i i bdi su di ehuyen ciia trgc tmng hda Dieu cho thay ring sg d n thiet phai xde dinh vi tri hifin tgi cua trye trung hda, bang cdch tinh lgi bien dgng, nfii lue vd tong nfii Igc tgi vi tri mdi, ldp Igi cho d i n tong npi luc bdng khfing Mdt Bdng Ket qua thuc nghiem vd tinh todn Dowing 1976 ReclI200 H200 H300 4400 da bilt dugc vj tri mdi ciia trgc tnjng hda thi se xdc djnh dugc chinh xdc phdn bo irng suit ciia cac phin tif k i t c l u TLP dd gid trj mfi men uon M, dol vdi tnjc trung hda mdi dugc suy bdi dfi cong k, bang cdch tong cdc md men ciia mfii phin tip ket d u III KET QUA NGHIEN CI>U VA T H A O L U ^ N Odnh gid tin c|y ciia chuong trinh tinh (1$ ben chung D l ddnh gid miPC dp tin cdy eua kit qua b'nh dp ben Chung tip chucmg trinh, chdng ta se so sdnh kit quS tinh ciia chuang trinh vdi kit qua thgc nghiem ed dugc KP cde miu thi nghifim da edng b6 ciia cdc nhd khoa hpc khde duge ^ n g hgp d tdi lieu [4], [5\, [7], [10], [11] ben chung ciia 26 mau thi nghi|m D$ b i n chung (M6 men tdri h^n M„) K | qud Unh todn tofln phan M Kdt qua thgv nghifin 2232 2613 6209 318.2 284.1 282.0 272.1 257 437.3 496 808.3 1061 812.1 812.1 914.9 914.9 1066 1066 2267 12790 1278 572.6 770.7 970 970 970 1517 2176 4537 229.4 229.5 266.6 262.1 228.2 407.6 486.8 588.4 927 482 672 593.3 838 1113 863 1511 9780.7 1238 349.1 643 ,526 269 026 40 • TRUONG OAI HOC NHA TRANG 1848 2113 4361 287.3 258.3 237 229.3 217.6 405.6 404.2 524 777 659.2 694.4 593 839 1001 767.1 1456 9481 1133 344.9 537 359 290 223 X 0.821 1.030 1.040 0.799 0.889 121 1.143 1.049 1.005 1.204 1.123 1.192 0.731 0.968 1.000 0.999 1.112 1.125 1.038 1.032 1.093 1012 1.197 1.123 0.984 0.839 Tap chi Khoa hoc - Cong nghe Thuy san Thdng qua viec ddnh gid hg so so sdnh X^ (X^ = K i t qud thg'c nghifim / Kit qud tinh todn cua chuang trinh) se nhdn bilt dugc mirc dg chinh xdc cua chuang trinh tinh Tip bdng cd the de ddng xdc djnh dugc (cho d 26 m i u thl nghifim) gid trj trung binh ciia X^ = 1.026, dp Ifich cua X^ = 12.24% [5] Nhu vdy, kit qua cd dugc cOa chuang trinh tinh Id chap nhfin Suae Tinh dg b i n chung cua tdu hdng rot 2000 DWT Hinh the hifin mgt d t ngang giO'a cOa tdu hang rdi 2000 DWT [2], dd x,: chieu ddy tdn vd ngodi, x^: chilu ddy tdn vd trong, x^: chilu ddy song chinh, X,: chieu ddy song phg x^: chieu cao sing ehinh vd s6ng phg, x^: chieu ddy bdn bung xd dpc mgn, x^: chieu cao ban bgng xd dpc mgn, x^: chilu ddy ban cdnh xd dgc mgn x,: chilu cao bdn cdnh xd dgc mgn Thdng s l vdt lifiu nhu sau: Md dun dan hli E = 207000 MPa; He so Poisson n = 0.3; l>ng suit chdysY = 2g7MPa "ll "1 - XJ^ 1^ Hinh S M^t cit ngang giiia cua \hu 20D0 DWT Mgt d t ngang di/gc phdn chia 15 phin tip ddnh so tip den 15 vdi vj tri va thdng so kich thudc cua cac phin tu nhu bdng Bang Bdng thdng s6 cdc phan t u cua mat cat ngang Phin h> tho Kich I h u ^ cda phin h> Tim N ^ gia cu^ng Vj tri g6c phin tir Phirong y Phiromg z 0 1600 3200 Ghi chu 1600*X1 FB 1600*x1 FB {Xg-X,.Xj)//x4 1600*x1 FB (Xg-x,-X5)/,*x4 1343.6*x1 FB (,x^-\-X.YZ'\ 4500 1338"x, FB(900-x,)/2.x2 5400 750 1475*x, TVKAX 5400 2200 1600'x, Tx,*x^x,*x 5400 3700 1100*10 FB 850*x, 5400 5400 1900*10 1400*10/100*10 3200 5426.5 10 1600*8 7400*8/100*10 1600 5429.8 11 1600*8 T400*8/100*10 6431.7 D6i xirng 12 1600*x, FB 750 B o i xu'ng 13 1600*Xj FB {x,-x,-x,)/2*x^ 1600 750 14 1450*x, FB (Xg-x,-x^)/2*x^ 3200 750 15 1100*x, FB (X5-X,-X^V2*X^ 4500 750 (Xg-X,-Xj)//X3 (X5-x,-X2)/2*X3 Vdi m i i bp thdng so mdt d t ngang (x, - Xg), chuang trinh tinh todn kilm tra gid trj momen u l n tdi hgn M^ (hay dfi ben chung dudi tdc dgng ciia md men u l n dpc hai ^ e u kifin tdu tren dinh sdng vd day sdng) Hinh la dfi thi cd dugc tir chuang trinh vdi cdc thdng s l 12, 10, 12, 10, 750 250, 10, 100 mm, tuung ung vdi cdc biln tir x, d i n x^ Trong hinh M la gid tri md men uon tuang irng Doi xijng G6o vdi dp eong k cua tn,ie trung hda tgi vj tri mat edt ngang dang xet Tip hinh 6, cd t h l xac djnh duac gia tn md men uon Idn nhit ma vd tdu chju duge d hai trgng thdi tdu nim d dinh sdng (Hogging codition) vd day sdng (Sagging codition) TCr gid trj so sdnh vdi gid tri rnd men uon theo quy phgm de bp thdng so mat eat ngang (x., - Xg) dang xdt cd thda man dilu kifin dfi bin chung hay khong TRIJONG OAI HOC NHA TRANG • 41 Tgp chi Khoa hoc - Cong nghe Thuy s So 3/2014 M • E+11 H o g j i n g condition M u = a2349E**12Nmm " ^ ^ / / / / -20 -15 -10 Sagging condition M u = 0.191OE+12 N m m -5 j / k • E-07 lO 15 20 / ^ ^ Hinh B$ b^n chung ci IV KtT LUAN Nhu vdy, dga theo thufit todn cua phuang phdp Smith, bdi bdo da xdy dung duge chuang trinh tinh todn dfi bin chung (hoae dp ben tdi han ultimate longitudinal strength) eiia tdu vo thfip d l phue vg cho bdi todn toi uu hda k i t d u Dp tin edy ciia chuang trinh da dugc minh chung qua ket qua so sdnh vdi ede nghifin CLPU thgc nghifim da cfing b l kn h i n g roi 2000 D W T eho kit qud khd chinh xac vdi sai Ifich vdi thgc nghiem 12.24% Dong thdi dp dgng d l tinh toan dfi bin chung cho tdu hdng rdi 2000 DWT cua Nha mdy Ddng tdu Nha Trang Ro rdng vdi chuang trinh tinh ndy, cd t h l sir dyng d l tinh todn nhanh dp bin chung ciia tdu vd thdp vdi dif lifiu dau vdo dan gidn Id kich thude hinh hgc cua mdt d t ngang vd thong s6 vat lifiu ca bdn TAI LIEU THAM KHAO Tieng VifI Pham Ba Linh, 2014 Nghien ciiu tfli iru hoa kit cSu tau vo thep sif dung k^t hop thuat toan chia doi va tim kidm tnjc Hep Tap chi Khoa hpc - C6ng n ^ e Thuy san, S6 45-51 Nha may D6ng tau Nha Trang, 2001 H6 sa thiSt ki ky thuat tau hang 2000 DWT Dang kiem Vi?t Nam, 1997 Quy ph^m phSn cSp va dong tau hiSn vo th6p TCVN 6952:1997 Ha N^i Tieng Anh Caldwell, J B., 1965 Ultimate Longitudinal Strength Transaction of RINA, 1965 107: p 411-430 Cho, SR., Choi, B.W, and Fneze.P.A Manual of ULSAN program 2001: School of Naval Architecture and Ocean Engineering, University of Ulsan Cho S.R., Choi, B,W., and Frieze, PA, 1998 Ultimate strength formulation for ship's grillages under combmed loadmgs Proceeding of the 7th International Symposium on Practical Design of Ships and Mobile Units PRADS'98 Hague: 125-132 Cho, S.R , and Song, I C 2000 Ultimate strength formulation for ship's grillages under combined loadings Joumal of Engineering Research Vol.31: 145-157 Cho S R and Song, I.C, 2003 Experimental Investigation on the Ultimate and Post-Ultimate Strength of Stiffened Plates under Axial Compression Joumal of Ship and Ocean Technology SOTECH, Vol.7, No.1 Huynh V.V, 2011 Residual longitudinal strength and Reliability analysis of Damaged ships Doctoral thesis dissertation University of Ulsan, Korea 10 lACS, I.A.O.C.S., 2010 Common structural rules for bulk carriers 11 Smith CS 1977 Influence of local compressive failure on ultimate longimdinal strength of ship's hull Proceeding of the International Symposium on Practical Design in Shipbuiidmg, 42 • TRUONG OAI HQC NHA TRANG ... kilm tra dilu kifin dp ben chung cua tdu Nhu vfiy qud trinh tinh toi uu se lifin tgc tinh todn gid trj dfi bin chung sau moi lan thay doi cdc thdng so mgt d t ngang Xdy dung thudt todn kilm tra. .. v l n edn tilp tgc phat triln nu''a Vai trd cua phuong phdp kilm tra dg ben chung bd) toan toi u u hda k i t c l u tdu vd thep Trong bdi todn toi uu, cdc thdng so cua mgt cdt ngang tdu ludn ludn... tugng nghifin ci>u Id chuang trinh kilm tra dfi bin chung tau v6 thdp theo phuang phdp Smith, ung dgng cho tdu chd hang rdi 2000 DWT Nhd mdy Odng tdu Nha Trang sdn xult ndm 2001 [2] theo quy phgm