NGHIEN CU'U - TRAO DOI DANH GIA TUOI THO Mdl CUA BO PHAN DAN Hdi NHIP LA TREN HE T H N G TREO C A N B A N G FATIGUE LIFE EVALUATION OF MULTI LEAF SPRING COMPONENT OF THE BALANCED SUSPENSION SYSTEM TS Vu Tuan Dat Trudng Dai hpc Giao thdng Van tai TOM TAT Mo hinh phdn tich tuoi thg moi cita bgphgn ddn hoi nhip la tren he thong treo cdn bdng phu thugc dugc xdy dung trin ca s& phuang phdp img sudt danh nghia lfng sudt tren mien th&i gian cua kit cdu dirng de phdn tich ben moi co duac bdng phuang phdp phdn tich phdn tuhiru hgn, v&i tdi trgng tdc dgng duac xudt tir ket qud mo phong dgng luc hgc da vgt the Tuoi thg moi cua phdn tir ddn hoi nhip Id duac tinh todn co xem xit den dnh hu&ng cita mdp mo mat du&ng & cdc van toe khdc Tir khda: He thong treo cdn bdng; Phdn tir ddn hoi nhip Id; Tuoi thg moi; Phuangphdp img sudt danh nghia; Mdp mo mat ducmg ABSTRACT In this paper, the fatigue life analysis model of multi leaf spring component ofthe balanced suspension system was built based on nominal stress - life method The stress time histories of this structure, which are necessary for fatigue life analysis, were obtained using finite element (FE) analysis method with load time histories, as the results of multi-body dynamics (MBD) simulation Fatigue life of multi leaf spring component were calculated with the effects ofthe road roughness and vehicle speeds are considered Keywords: Balanced suspension system, multi-leaf spring component, fatigue life, nominal stress - Life method, road roughness DAT VAN DE Bd phdn ddn hdi nhip la (Multi leaf spring component- MLSc) ciia he thdng h-eo cdn bdng thudng dupc sii dyng d cau sau tren cac d td cd tdi trpng ldn va la ket cdu chm luc chmh ndi ddn hdi giua khung va phan khdng duac treo Trong qua trinh khai thdc, mdp md mat dudng duac xem la nguyen nhdn chu yeu gdy tai trpng ddng tdc dung len bd phan dan hoi, ddn ddn kdt cdu xudt hien iing suat thay ddi cd chu ky va cd thd gdy phd hiiy mdi ISSN 0866 - 7056 TAP CHi CO KHI VlfiT NAM, So nam 2017 www.colihivietnam.vn NGHIEN CU'U-TRAO DO) Trong bai bao nay, de tinh toan tudi thp mdi Clia MLSc he thdng treo cdn bdng tren xe Hyundai HD700, tac gid da kdt hpp phuong phdp phdn tich phdn tir hiiu ban (Finite element - FE), md phdng ddng luc hpc da vdt thd (Multi-body dynamics - MBD) va phucmg phap phdn tich tudi thp mdi theo iing sudt danh nghia Tren co sd do, tien hanh khao sdt dnh hudng cua mdp md mat dudng va v^n tdc chuyen ddng cua d td den tudi thp mdi cua ket cdu lupng rieng, ) dupc sir dyng dd xay dyng cdc md hinh - Md hinh FE cua cua MLSc va cac bdi todn phdn tich ket cdu (phdn tich dac tnmg rieng de cd tep *.mnf ddc trung cho vdt ddn hdi; Phdn tich dpng lyc hpc ket cau de cd iing sudt yen mien thdi gian) bang phdn mem ANSYS: Phuang phap nghien ciiu dupc so dd hda nhu hinh 1: - Md hinh MBD va md phdng dao ddng cua d td dudi kich thich ciia map md mat dudng cd xem xet den dnh hudng cua van tdc d td; trich xudt tai trpng tac dung len MLSc ldm thdng sd ddu vao cho phan tich ddng luc hpc ket cau bang phdn mem ADAMS: - Tham sd kdt cdu, tham sd ddng lyc hpc (hinh dang, kich thudc, trpng lupng, tpa dp tam, dac trung qudn tinh, ciing, ) va thudc tinh vat lieu (md dun dan hdi, khdi - Phdn tich tudi thp mdi cua MLSc theo phuang phap iing sudt danh nghia vcri thdng sd ddu vao Id thdng ke chu trinh iing suat bang phdn mem nCode DesignLife PHU'ONG PHAP NGHIEN ClTU Thim so kel cia, tbam so fl^ag hrc hi^c, vf t lieu J: I M6 hinh MBD cua to (AD.AMS) in Mo phdng dao Map md m|t dirdng, vfB (oeo Aid hmh phan tich df bla mol (heo teg salt daah ighia (nCode U— DesigaLife) TboBg kg cbn t^ u^sajt Hinh • Mo hinh phdn tich tudi thp mdi cda kit cdu ISSN 0866 - 7056 TAP CHi CO KHi VlfiT NAM, Sd nam 2017 www.cokhivietnam.vn NGHIEN CU'U - TRAO D | Md hinh FE cua MLSc dupc xdy dung bdng ANSYS (hinh 2) cd xem xet ddn trang thdi tiep xtic giiia cac Id nhip va luc xidt ban ddu ciia bu long quang nhip da dupc tac gia cdng bd tai lieu [1] Thudc tinh vdt lieu ciia bp phdn dan hdi nhu sau: Thep dan hdi 60Si2MnA, gidi ban chdy o^=1373 MPa, gidi han ben 0,^=1570 MPa Md hinh MBD ciia d td tdi Hyundai HD700 vdi ket cau MLSc dupc xem nhu vdt the dan hdi - Flexible body [2] va ket qua khao sat anh hudng cua mdp md mat dudng va van tdc chuyen ddng den dao ddng cua d td da dupc tdc gia cdng bd tdi lieu [3] Trong dd, mdp md mat dudng dupc md phdng tren ca sd ISO 8608:1995 (phan cdp mat dudng theo mat dp phd cdng suat) va phuong phap bien ddi nguac Fourier [4] cua MLSc ttong ANSYS Su dung phuang phdp phdn tich ket cdu vdi tdi ttpng thay ddi tten mien thdi gian de thu dupe trang thdi img sudt tai cac diem nut vd tdp ket qua (*.Tst) Tren hinh la gia tri iing sudt tuang duong Von-mises tai diem mit 5229 md hinh FE ciia MLSc tuong iing vdi 200 budc tai ttong ddu tien md phdng d td chuyen ddng tren dudng cdp C vdi vdn tdc 60 km/h So sdnh vdi ket qua ttong [1], cd the thdy gid tri iing suat dpng cac la nhip ldn hon so vdi gia tti ling sudt tinh ldn nhdt (743,78 Mpa) Sii dung thudt todn thdng ke chu trinh iing suat (Rainflow-counting algorithm) ddi vdi diem niit 5229 ta cd ket qud nhu tten hinh 4: True tung la sd lan sudt hien chu ky iing suat tucmg ling vdi bien dp img sudt tten true hodnh Hinh Ung sudt Von-mises ciia diem nut 5229 Htnh Md hinh PTHH cua bp phdn ddn hdi nhip Id PHAN TICH DONG LU'C HOC KET CAU CHO MLSc Lya chpn chd dp khao sdt nhu sau: td chuyen dpng thing tren cdc loai mat dudng: Cap C (trung binh), cap D (xau) va cdp E (rat xau); vdi van tdc chuyen ddng ciia d td: 20 km/h, 40km/h, 60 km/h va 80 km/h Trong ADAMS, tai ttpng tdc dung len MLSc tai cac diem hen kdt vdi phdn dupc treo va phdn khdng duac treo dupc xudt thdnh cac tdp tai ttpng (*.lod) vd dupc ddn nhap vd md hmh FE 50 100 150 200 Stress range 250 319.1 Hinh Thong ki chu trinh img sudt cua diem mil 5229 ANH HlTCTNG MAP MO MAT DU'ONG DEN TUOI THO MOI MLSc LTng dung phan mem nCode DesignLife de tinh toan tudi thp mdi theo phuong phdp"^^ ISSN 0866 - 7056 i CO KHi VIET NAM, Sd nam 2017 -.4lzli:.^'.ltn.]m NGHIEN CLfU - TRAO DOI ung suat danh nghia, tuoi tho moi dugc hieu la so chu ky ling suat cho den xuat hien vet nut moi Moi quan he giiia iing suat a va so chu ky tuan hoan N din den hu hong moi cua v§t lieu {hay goi va duong o-N) nhu hinh Trong do, Oj^, la ben moi voi N=l chu ky; S^=cj2 la gicri han ben moi co Nj.,=10''chu ky; b, va bj la goc nghieng cua cac doan thang Cac gia tri dugc tinh theo cong thuc sau [5]: = 0.9cr,;crj = o - j ; 20-, (lga-,-lgg,) ' chuyen ddng tten mat dudng cdp E vdi van tdc 60 km/h Cdc ket qua phdn tich deu cho thay cdc diem cd tudi thp mdi thap nam d cdc vi tri: Gdn vi tri hai ddu nhip chmh tidp xiic vdi gdi da tten cdc cau; cac vi tri la nhip dudi tiep xiic vdi ddu Id nhip tten; vi tri Jd bu ldng dinh vi, day cilng la cdc vi tri tap trung ling suat ket qud tmh toan cho thdy mdi thp mdi thdp nhdt (N ) cua MLSc tuong iing vai 12 che dp khdo sdt (3 cap mat dudng vdi loai van tdc chuyen ddng ciia d td khdc nhau) cho ttong bang Cd the nhan thdy mdp md mat dudng mdp md mat dudng vd van tdc chuyen dpng d td tang thi tudi thp mdi cua MLSc gidm (1) (lg^c,-3) (2 + *,) Hinh Phdn bo tuoi thg moi ctia MLSc vdi mat dudng cdp E, van toe d to 60 km/h 10' iV„ •^ N Bdng I Tuoi thp mdi N^^^ cita MLSc a cdc dieu kiin khdc thdc khdc nhau: Hinh Duong o-N cua vgt liiu Tinh dupc cdc gia tri: a|=1413 Mpa; 0^=560,5 Mpa; b,=-0.13386 va ^ 0.07173; CT^-7124,4 Mpa V5n toe oto C9pC C9pD CapE 1,787E+17 1,650E+15 2,744E+1I 40 km/h 1,441E+16 4,097E+1I 2,336E+7 60 km/h 4,037E+13 3,858E+8 7,017E+4 80 km/h 1,389E+10 2.362E+5 6,147E+1 20 km/h Dan nhap tep ket qua (*.rst) ttong ANSYS vdo md hinh phdn tinh tudi thp mdi ttong phdn mem nCode DesignLife dd tinh tudi thp mdi cho MLSc Tren hinh Id phdn bd tudi thp mdi cua MLSc tuong iing d td Tuoi tho moi thdp nhat N„^ (chu ky) ISSN 0866 - 7056 TAP CHi CO KHi VIET NAM, Sd nam 2017 www.cokhivietnam.vn NGHIEN CCrU-TRAO D | KET LUAN Tai ti^u tham khao: Bai bao da ket hpp giiia phdn tich ket cau bang phuang phap FE, md phdng MBD va phdn tich tudi thp mdi theo phuang phdp img suat danh nghTa de nghien ciiu tudi thg mdi cua MLSc cua he thdng treo cdn bang tten d td Hyundai HD 700 Ket qud nghien ciiu cho thdy, dp map md ciia mat dudng vd van tdc chuyen ddng cua d td tang thi tudi thp mdi Clia MLSc giam Khuyen cao ban che van hdnh d cac che dp ma tudi thp mdi N^^ cua MLSc thdp ban 10* chu ky.*l« [1] [2] [3] [4] Ngaynhanbai: I0/6/20I7 Ngay phan bien: 20/6/2017 [5] Vu Tuan Dat (2016); Xdy dung duang ddc tinh ddn hdi vd kiim tra bin cho bp phdn ddn hdi nhip Id, Tap chi Khoa hoc Giao thdng Van tai, so 54, pp: 33-38 MSC.Software Corporation of MDI (2002); ADAMS/FleX'Theory of Flexible Bodies Printed in the United States of Amenca Vii Tudn Dat (2016); Khdo sdt dao dgngcua to ddu keo HD700 tren ca sd mo phong dong lire hoc da vdt thi cd ki din biin dang ddn hot Tap chi Khoa hgc Giao thdng Van tai, so 54, pp: 68-73 Liu X.D, Deng Zh.D and Gao F (2003) Research on The Method ofSimulating Road Roughness Numerically Journal of Beijing University of Aeronautics and Asttonautics, Vol 29(09), pp- 843-846 HBM-nCode (2010) ANSYS 13,0 nCode DesignLife - Theory Guide Printed in United Kingdom ISSN 0866 - 7056 TAP CHi CO KHi VlfiT NAM, Sd ndm 2017 ... 80 km/h Trong ADAMS, tai ttpng tdc dung len MLSc tai cac diem hen kdt vdi phdn dupc treo va phdn khdng duac treo dupc xudt thdnh cac tdp tai ttpng (*.lod) vd dupc ddn nhap vd md hmh FE 50 100...NGHIEN CU''U-TRAO DO) Trong bai bao nay, de tinh toan tudi thp mdi Clia MLSc he thdng treo cdn bdng tren xe Hyundai HD700, tac gid da kdt hpp phuong phdp phdn tich phdn tir hiiu ban... thp mdi theo phuang phdp img suat danh nghTa de nghien ciiu tudi thg mdi cua MLSc cua he thdng treo cdn bang tten d td Hyundai HD 700 Ket qud nghien ciiu cho thdy, dp map md ciia mat dudng vd