Mô phỏng số quá trình hình thành khuyết tật gấp khi dập tạo hình phôi ống

NGHIEN cuu-TRAODOI MO PHONG SO QUA T R I N H H I N H THANH KHUYET TAT GAP KHI DAP TAO HINH PHOI ONG NUMERICAL SIMULATION OF FOLDING DEFECT DURING FORMING PROCESS OF TUBE TriroTig Minh Du-c, Hoang Anh Tu4n, NguySn Thanh Huan, Nguyen Van Miii Truong Dai hpc Kinh te Ky thuat Cong nghiep TOM TAT Cdc sdn phdm duac che tao tir cong nghe gia cong dp luc co the ton tai nhieu khuyet tat xudt Men qud trinh gia cong Mot nhimg khuyet tdt hien vd nguy hiem nhdt Id khuyet tdt gdp Be nghien cihi ve su hinh khuyet tat dap tao hinh chi tiet tie phoi ong bdng thtic te Id dieuw cung kho khan Bdi bdo trinh bdy qud trinh hinh thdnh khuyet tdt dap tao hinh phoi dng tren co sd mo phdng so bang phuong phdp phdn tu him han Vdi ket qud thu duac ta co the img dung vdo thuc te de tao duac cdc chi tiet dgng ong bdng cong nghe ddp khoi md khong phdi dimg them bdt Id moi nguyen cong nao Tir khoa: Khuyet tdt; Gdp; Mo phdng sd; Ddp tao hinh ABSTRACT Many defects can appear in the products made by metal forming technology Folding is one oftk most common and deteriorating defects of forged components To study the defect formation durin forming process with tube workpiece in practice is extremely difficult formation This paper presents the defecl in tube upsetting using numerical simulation with the finite element method The obtaim!> results, will be applied to create the tubular parts by forging technology without using any more Oj otheroperations Keywords: Defect; Folding; Numerical simulation; TAP CHI CO KHI VIET NAM, S6 nam 2014 www.cokhivietnam.vn Forming NGHIEN cuu-TRAODOI GI0I THIEU Xuat phat tu yeu cau thuc tiln ciia nganh Cong ighiep ca noi chung va nganh Gia cong ap lire loi rieng, v^ viec giam ehi phi dau vao cho qua rinh san xuit (nang lupng, vat lieu, nhan cong ) /oi muc dich nhim tao eac san phdm eo chit uong ve mat ki thuat, song ben eanh nguai thilt ik eon mong mu6n tao mot san phim co tinh ;anh dranh cao ve mat kinh tL Xet th4y thuc :e CO rat nhieu ehi tiet may dupe gia cong dk tao 3han lo r6ng Nhung hi mioc dSn nay, nhiing ehi :iet chu yeu duac tao hinh tii phoi dae va sau 16 phai su dung them mpt so nguyen cong de gia :6ng 16 rong Qua trinh lam nhu vay se lam tang ;hem rat nhieu chi phi va thoi gian, khong nhung vay, lam cho dp ben ciia chi tiet giam di, gay nguy hiemfrongqua hinh lam viec Qua thuc tg nguai ta dat yeu cau can thiet phai nghien eiiu de iim cong nghe phu hpp Tuy nhien, tien hanh tao hinh cac ehi tiet bang cong nghe dap khoi, thuang xuat hien khuyet tat, dac biet la khuyet tat "Gap" - mot nhung khuyet tat kho phat hien va anh huang Ion nhat den dp ben va tuoi tho cua chi tiet may Khuyet tat xuat hien rat nhieu tao hinh san pham tir phoi rong De nghien cuu v^ su hinh khuyet tat bang thuc te la dieu v6 eimg kho khan Bai vay, thong qua mo phong s6 chiing ta CO the xay dung bai toan dap tao hinh ehi tiit tir phoi ong Tir ta co the dua phuang phap phii hpp de tranh khuyet tat gap chon va dap khoi cac chi tiet rong Nha th8 chung ta co thi tao duac nhiing san pham chat lupng cao vai chi phi hgp li de tir nang cao duac tinh canh tranh QUA TRINH HINH THANH KHUYET TAT DO MAT N DINH TRONG CONG NGHE TAO HINH VAT LIEU 2.1 Sy hinh khuyet tat gap nguyen cong chon Nguyen cong chon thuong thuc hien vai dang phoi dien hinh la phoi dac va phoi rong So nguyen cong dupe bieu diln bang hinh duoi day t(U/(// UA aiLu,ILLLLU r l/z/yT////// vrrr TT : rtYTrTTT d, a) Chon phoi dgc: d., i b) Chon phoi rong; Hinh 2.1; Sa nguyen cong chon phoi Thirc td ch6n, phoi co kha nang mit on dinh do: Ty le chieu cao phSi so vai duong kinh phoi qua Ion se din Sin hien tugng mat on dinh IChi do, neu ta tiep tuc chon phoi, phoi se bi gap lai tao khuySt tat NSu phoi rSng vai mong thi ch6n co the xay khuyet tat "gip" Cac truong hgp xuSt hien khuySt tat "gip" dSu la phoi mit on dinh nhu hinh 2.2, 2.3 TAP CHI CO KHI VIET NAM, So nam 2014 www.cokhivietnam.vn NGHIEN cuu-TRAODOI Hinh 2.2; Phoi bi cong mdi on Hinh 2.3; Sdn phdm bu long bi khuyet tdt sau chon dinh qud trinh chdn Trong cac nghien cuu truoc day nguoi ta mai chi de cap dSn hien tugng mat on dinh va each khat phuc no ch6n phoi die phoi r6ng lai rit it de cap den Trong do, tao hinh ta lai phai sit dung phoi r6ng ii ti& kiem vat lieu Tuy nhien, phoi rong mit on dinh nhanh Mot nhOng nguyen nhan gay mit in dinh ch6n phoi rSng la duong kinh 16 phoi Ion hay phoi tru rdng mong, 2.2 Su- hinh thinh khuySt tat nguyen cong dap kh6i Cong nghe dap khdi dugc phan loai hai dang: Dap khoi long khuon kin va dap khoi long khuon hg Mgt nhimg yeu to chung ta quan tam nhat cong nghe la su hinb khuyet tat ciia chi tiet sau tao hinh Tuy nhien, viec xac dinh nhiing khuyet tat thi khong he dgn gian boi le nhirng khuyet tat dugc hinh ben long vat the Hinh 2.4: Hinh dnh mophongqud trinh dap chi tiet cd hoc lom Hinh 2.5; Hinh dnh mdphongqud trinh ddp khuon h& cd vdnh bien Hinh 2.6: Hmh dnh md phdng nguyen cdng dap Hinh 2.7: Hinh dnh md phdng nguyen cdng khdi chi tiet khdp ndi khuon hd cd vdnh bien ep chay ket hap vai ddp khdi khudn hff cd vdnh bien v&i chi tiet dgng hinh tru O: Vi tri xudt hien khuyit tdt gdp TAP CHi CO KHi VIET NAM, S6 nam 2014 www.cokhivietnam.vn NGHIEN cuu-TRAO DOI Qua nghien euu tir bon truong hpfp tren ta thay mpt nhiing dang khuyet tat ph6 bi^n va nguy hiem nhat eong nghe dap kh6i la khuyet tat "Gap" Tuy nhien, t4t ca cac truong hop tren d^u dupe nghien cuu khao sat qua trinh tao hinh tix phoi dac D6 tinh toan qua trinh mat 6n dinh tao khuyet tat tao hinh chi ti^t hi phoi ong ta tien hanh xay dung bai toan chon phoi 6ng Day la mpt dang bai toan mat on dinh dan gian nhat, nhimg ket qua lai co the ap dung cho nhirng truong hpp tao hinh a eae nguyen cong khac KHAO SAT QUA TRINH BIEN DANG MAT ON DINH GAY KHUYET TAT GAP KHI DAP TAO HINH PHOI N G Khi nghien euu qua trinh dap tao hinh phoi ong, ta thay day la mpt qua trinh bien dang khong on dinh va khong dong deu anh huang ciia nhieu yeu to nhu: Hinh dang phoi ong (chieu eao phoi, duong ben ngoai eua phoi, chieu day phoi ), ma sat giua phoi va khuon, nhiet dp chon Tuy nhien, bai bao ehiing toi ehi nghien euu su anh huong hinh dang ciia phoi den qua trinh bien dang De nghien ciiu qua trinh mat on dinh ta tien hanh mo phong qua trinh chon phoi ong cac truong hop khac Tien hanh thiet lap mo hinh bai toan ch6n phoi ong bang bien dang deo nha irag dung phan mem DEFORM dupe thuc hien qua cae buac tir xay dung mo hinh hinh hpc, mo hinh luai phan hi, mo hinh vat lieu cho den cac dieu kien bien the hien qua trinh chon phoi ong phii hpp voi thuc te nhu dieu kien ma sat giiia vat lieu va dung cu gia eong dupe the hien mo hinh tiep xuc hay cac thong so cong nghe ciia qua trinh mo hinh dieu kien bien Hinh 3.1: Md hinh hinh hoc bdi todn chdn phdi dng Hinh 3.2: Diedng cong chdy cua vdt lieu f\ Hinh 3.4: Md hinh ludi phdn tu bdi todn chdn phot dng Hinh 3.5: Cap tiep xuc giUa khudn vdphdi TAP CHI CO KHi VIET NAM, S6 nam 2014 www.cokhivietnam.vn NGHIEN cuu-TRAO DOI Sau thiat lap mo hinh bai toan ta tiin hanh mo phong voi cac truong hgp khac nhau: Trong do, ta c6 dinh duong kinh ben ngoai cua phoi, chik day phoi, chiSu cao cua phoi thay doi nham khao sat su anh huong cua kich thuoc phoi tai hanh trinh ep gay mit 6n dinh Cu thi la: Chieu cao phoi H = 25mm, 50mm, 100mm; Ducmg kinh ngoai phoi D = 50mm; Duong kinh 16 d = 10mm, 20mm, 30nmi, 40mm Bdng 3.1 Bdng kit qud ciia su mat in dinh qud trinh chon phoi ong qua cdc mo phdng H/D ; s w 7a 0.5 Step 65 Step 62 S=20 Sleo 11 Step 56 Step 65 S=15 S=10 Step 30 Step 36 i S=5 Qua cac truong hgp ma khao sat a tren, ta xay dung dugc mgt bilu d6 v6 m6i quan he giOa su mat 6n dinh ch6n phgi gng va ti so s/D (ty s6 giOa chiju day phoi va duong kinh ngoai cua phoi) Qua thi ta rut nhan xet nhu sau: Ba duong bieu dien su mat 6n dinh tren thi ta thiy duong nao cang d6c tuc la duong i( TAP CHi CO KHi VIET NAM, S6 nam 2014 www.cokhivietnam.vn NGHIEN cuu-TRAODOI CO sir mat on dinh cao nhkt Cu thS la duong H/D ^ la duong co sir mat on dinh eao nhit Diem cao nhat se la diem it mat on dinh nhat Cac duong lai la H/D = va H/D = 0.5 co dp doe be hon, dieu chimg to ta thay d6i chieu day s ciia phoi chi tiet chon it mdt 6n dinh hon Khi xet ve ty so giiia hanh trinh chdn xu^t hien hien tuong mat on dinh va chieu eao phoi Chieu sau mfit on dinh ch6n (mm) (h/H) vai cac phoi eo cung duong kinh, ngoai nhung khac ve chieu cao ta thay phoi cang cao ty so cang be Dieu co nghia rang phoi cang cao cang nhanh mat on dinh Vi du nhu chon phoi co chieu cao H= 100mm voi s - 20mm ta thSy ti s6 h/H = 59.25/100 = 59.25% Trong do, neu la phoi co chieu eao H - 50mm ta th4y h/H - 31/50 = 62% Tuong tu nhu vay, voi phoi co H = 25 ta thay ty so h/H = 16.5/25 = 66% Kich thudc phOi mit 6n dinh (mm) Hinh 5: Do thi mdi quan he giita chiiu day phdi vd mdt dn dinh chiiu cao phdi thay ddi Hinh 6: Dd thi mdi quan he giita chieu cao phdi vd mdt dn dinh chieu day phdi thay ddi KET LUAN suat, bien dang ciing nhu dong chay ciia kim loai Thong qua viec danh gia ket qua mo phong, ehiing ta eo th6 dl dang tim khuyit tat, dac biet la khuyit tat gip, nha vay, nguai thilt ke eo the thay d6i cac thong s6 diu vao de xac dinh phuong an cong nghe t6i uu Khi phan tich, nguai ky su cong nghe hoan toan co the dua vao phan bo ung de tranh cac viing tap chung ung suat, vimg vat lieu kho bien dang, no se lam cho chat lugng san pham khong cao Trong truong hpp chi can thay doi cac kich thuoc hinh hpc ciia dung cu gia cong ciing nhu eac dieu kien bien dang cho phii hpp TAP CHI CO KHI VIET NAM, So nam 2014 www.cokhivietnam.vn NGHIEN cuu-TRAO 001 KSt qua trinh bay bai bao co the cho phep ta danh gia dugc t6ng quat qua trinh hSU khuySt tat tao hinh san pham tir phoi ong, tren ca so ung dung phan mem mo phong si DEFORM Vi vay, co the tranh cac anh huang xSu toi chit lugng san p h i m , tranh dugc hien hipmg mdt 6n dinh tao hinh phoi 6ng, nguoi ky su co sir tinh toan tdi uu nhat che tao phoi va thiel k^ khuon dap cac phoi dang 6ng.*;* Ngay nhan bai; 16/02/2014 Ngay phan bien: 17/3/2014 Tai lieu tham khiio: [ ] Nguyin Dac Tnmg (2011), Md phong so qud trinh biin dang, NXB Bach khoa Ha Ngi [2] Nguyin Trgng Giang, Nguyin Viet Hiing (2003), ANSYS vd Mo phong so cong nghiep bdng phan tii hiiu han, NXB Khoa hoc va Ky thuat Ha Ngi [3] Nguyin Tit Tiln, Ly thuyit biin dang deo, NXB Giao due Ha Noi (2004) [4] Nguyin Tit Tiln, Nguyin Die Trung (2006), Ly thuyit dap tao hinh, NXB Bach Khoa Ha Npi [5] "^Simulation Of Folding Defect In Forging^', M.Poursina , J.Parvizian [6] Boroomand, B., Parvizian, J and Pishevar, A.R (2002), ''Contact Modeling in Forging Simulation", Joumal of Materials Processmg, Vol 125/126, pp 583-587 TAP CHI CO KHi VIET NAM, So nam 2014 \v>vw.cokhivietnam.vn ... xuSt hien khuySt tat "gip" dSu la phoi mit on dinh nhu hinh 2.2, 2.3 TAP CHI CO KHI VIET NAM, So nam 2014 www.cokhivietnam.vn NGHIEN cuu-TRAODOI Hinh 2.2; Phoi bi cong mdi on Hinh 2.3; Sdn phdm... vdnh bien v&i chi tiet dgng hinh tru O: Vi tri xudt hien khuyit tdt gdp TAP CHi CO KHi VIET NAM, S6 nam 2014 www.cokhivietnam.vn NGHIEN cuu-TRAO DOI Qua nghien euu tir bon truong hpfp tren ta thay... a eae nguyen cong khac KHAO SAT QUA TRINH BIEN DANG MAT ON DINH GAY KHUYET TAT GAP KHI DAP TAO HINH PHOI N G Khi nghien euu qua trinh dap tao hinh phoi ong, ta thay day la mpt qua trinh bien dang