The numerical simulation on welding stress field of high strength steel. for axle case steel 390Q

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1 Advaced Mateials Reseach Olie: ISSN: , Vols. 9-4, pp doi:10.408/ 011 as ech Publicatios, Switelad he umeical simulatio o weldig stess ield o high stegth steel o ale case steel 90 Ya Yu 1. a,fegue Wag 1. b,ju Che 1..c ad Zhe Liu 1. Ke Laboato o Advaced Stuctual Mateials Miist o Educatio Chagchu Uivesit o echolog Chagchu 1001, Chia;. Miist o Machie Buildig Habi weldig taiig istitute,habi ,Chia;. Jili Sciece ad echolog Iomatio Istitute Jili 101,Chia a ua8788@16.com ; b agguag_1017@16.com; c cheju106@16.com; Kewods:ale case steel, 90, umeical simulatio, weldig stess ield Abstact: his pape takes the butt joit o ale case steel as eseach object, simulates the eal-time thee dimesioal damics CO shielded weldig o weldig stess ield b FEM sotwae ANSYS ad obtais the ale case steel 90 s tasiet stess ield o weld oe at dieet weldig speed. O that basis, the easible damic simulatio method o thee-dimesioal stess weldig ield which povides theoetical basis ad guidelies o optimiig weldig techolog ad om weldig paametes was poposed. he esult o weldig stess simulatio shows that the weldig stess is the lowest whe the optimum weldig speed is 5mm/s Itoductio I the domestic tuck mauactuig, the poductio pocess o ale case has bee switchig to the ale castig weldig ale case step b step,heeoe, the ualit cotol o weldig ale case is the ke to icease the sevice lie o welded ale. Impulse weldig ale housig is a ke compoet o the bodwok, the mateial popeties o the ale case aects its pocess peomace ad sevice lie diectl. he high stegth steel o ale case steel 90 was mied with Ni,i ad othe allo elemet, this make it have a good capabilit o ield stegth ad tesile stegth,ad the cotolled ollig ad cotolled coolig i ollig pocess wee also studied ad the obtaied the supeie cstal paticle.it has high mechaical popeties ad its possible to substitute o the 16ML steel ad become to the mateials o the medium ad heav dut tuck ale case i the utue [1]. he steel weldig pocess paametes o the high stegth steel 90 was simulated b usig FEM simulatio sotwae ANSYS, ad povided a epeimetal evidece o the pactical poductio. 1 A weldig tempeatue ield b iite elemet method 1.1 he basic euatios o the iite elemet Weldig is a pocess o heatig the patial o wok pieces to a high tempeatue istl ad the cools dow apidl. Alog with the movemet o the heat souce, the tempeatue o the weldmet chages with time ad space apidl. At the same time, the themal phsical popeties uickl va with tempeatue, ad thee is the pheomeo o latet heat whe usio o phase chage takes place. heeoe, the aalsis o weldig tempeatue belogs to the tpical oliea tasiet heat All ights eseved. No pat o cotets o this pape ma be epoduced o tasmitted i a om o b a meas without the witte pemissio o as ech Publicatios, ID: , Peslvaia State Uivesit, Uivesit Pak, USA-05/0/16,1:50:5

2 coductio poblem. he D o-liea heat coductio euatio is as ollow: Whee C is the speciic heat capacit o mateial; is coeiciet o heat coductivit; is the tempeatue distibutio uctio; is the heat souce; t is the heat tase time. hese paametes,ρ,c ae chage with the tempeatue. Calculatio o weldig tempeatue ield is usuall used i the ollowig two bouda coditios: 1 Heat lu distibutio o the kow bouda Objects ad the suoudig media betwee the heat echage o the Kow bouda Whee: s is pe uit aea o the eteal iput heat; β is the suace heat tase coeiciet; a is ambiet tempeatue; s is the tempeatue o the bouda kow;, ad is the outwad omal diectio cosies o the bouda. 1. he basic model o weldig heat souce 1..1 Gauss heat souce model Eaga ad sai [] the heat spot weldig heat lu distibutio o appoimatel Gaussia model used to descibe the weldig heat souce o heat lu ca be epessed as ollows Gaussia distibutio uctio: 1.4 ep R m 1.5 m πr 1.6 ηui Whee: m is the maimum heat lu heatig spot cete, J/m s. R is the ac eective heatig adius, mm; is the heat souce i a poit-to-ac heatig spot cete distace, mm; is the heat souce tasiet to the weldmet heat, W; η is the weldig themal eiciec; U is the ac voltage, V; I is Weldig cuet, A. 1.. Double ellipsoid heat souce model Did ot coside the Gaussia distibutio uctio o the peetatio o the ac, i ode to ovecome this shotcomig, A Goldak [-4] poposed a double ellipsoid heat souce model. his model o the weld pool beoe will be o a 1/4 ellipsoid ad the est o pat will be o aothe 1/4 ellipsoid. Let the ist pat o the eeg actio o ellipsoidal 1, the latte pat o the eeg actio ellipsoid ad 1 he ist hal o the ellipsoid heat souce distibutio uctio: 7. 1 ep 6 / 1 c b a abc π he secod hal o a ellipsoid heat souce distibutio uctio: 8. 1 ep 6 / c b a abc π 1.1 t c ρ 1. s a β. 1,,, t s Advaced Mateials Reseach Vols

3 7 Advaced Mateials, CEAM 011 I euatio 4 ad 5 o a, b, c, c ma be desiable dieet values, the ae idepedet o each othe. I the weldig o dieet mateials ca be divided ito 4 double ellipsoid 1/8 ellipsoid lap, each ma coespod to dieet values o a, b, c, c. Phsical model.1 Fiite elemet model Usig ANSYS sotwae modelig, sample sie is 100mm 70mm 10mm, mateial is 90 steel, Ac moves alog the weldig cete. he iite elemet model is a smmetic costuctio. We ca take hal o model i iite elemet aalsis Figue -1: Figue -1 hee-dimesioal diagam Figue -hee-dimesioal mesh diagams. he deiitio o mateial paametes he calculatio o weldig tempeatue ield belogs to o-liea tasiet heat tasmissio, the themal peomace paametes o the mateial va with tempeatue ad the phsical peomace paametes o ma mateials wee ot completed. Fom the liteatue [5] [6], we kow that the themal phsical peomace paametes o 90 steel was withi the scope o 0 ~000. I ode to achieve the covegece o calculatio, we ca adjust the paametes i high tempeatue, duig the pocess o calculate, we ca also popel adjust the paametes o mateial popet i high tempeatue. he esults have o chages obviousl.. he deiitio o elemet tpes ad mesh Because o the weldig is a ve ueve heatig pocess ad the tempeatue gadiet at the weld seam is lage, the poducig stess distibutio is ot uiom. Applicatio ecpted mesh to weld ad patl i meshig, i the a awa om the weld aea, eeg tase is slow, stess gadiet is elativel small ad the we ca use a elativel spase gid o cells. I a wod, we should maitai accuac ad educe the umbe o the gids at the same time. Fo this issue's chaacteistics, I we cotiue to adopt the tempeatue ield o meshig sie 1mm, while its computatio time is too log, theeoe, i ode to educe the computig time ad esue accuac, the coespodig lage mesh we use i the weld ad heat aectig oe ea the mesh aea sie wee set as 1.75mm,.5mm,.85mm, speciic mesh case show i Figue -..4 Cotol o load ad pocess Calculatio he load imposed i Calculatio o themal stess is the esult o calculatio o the tempeatue ield, so we just iput the tempeatue value o each ode.he time step legth we set is the same as tempeatue ield calculatio, I ode to iput the tempeatue load ad impove accuac o calculatio.

4 Advaced Mateials Reseach Vols he metal has bee melted i the weldig pocess i the weld pool aea. Its mechaical popet is eo, all its stess ad stai will disappea. heeoe, we adopt the method o etaiabado [7]. I eve step o the themal stess calculatio, we choose the coespodig esults o calculatio o tempeatue ield, ad abado the uit o eceedig the meltig poit, ad etai the uit below the meltig poit. Whe the sstem ead the tempeatue, it will abado the uit that the tempeatue is above 1500 meltig poit ad etai the uit that the tempeatue is below 1500.We used the data etaied to simulate the molte metal is i the eo-stess state. Reeece tempeatue is still set at oom tempeatue 0 he esults ad aalsis o weldig speed simulatio Accodig to the mateial ad thickess o steel plate we choose the most appopiate weldig paametes as ollow,ac voltage u is 18V; weldig cuet is 140A; themal eiciec η is 0.7; ac eective heatig adius is 5mm Weldig speed is 4mm/s, weldig time is 5s. a the stess ield o the weldig time at s b the stess ield o the weldig time at 1s c the stess ield o the weldig time at 4s d the stess-stai cuve o weldig time at 4s o weldig steam Figue -1 he stess ield ad stess cuves o the weldig speed at 4mm/s We ca kow om Figue -1 that whe the weldig speed is 4mm/s ad the weldig time espectivel is s,1s ad 4s, the stess distibutio espectivel is 059~7 109MPa, 5511~ MPa ad ~1 109MPa. Figue - o the 5s, 10s ad 19s alwas cloud is the stess ield ad stess distibutio cuve whe the weldig speed is 5mm/s ad the weldig time o the 0s.

5 74 Advaced Mateials, CEAM 011 a he stess ield o the weldig time at 5s b the stess ield o weldig time at 10s c he stess ield o weldig time at 15s d the stess cuves o weld seam at dieet positios Figue - he stess ield ad stess cuves o the weldig speed at 5mm/s Figue - om the thee dieet weldig times o stess cloud ca be see that whe the weldig speed is 5mm/s, the weldig time espectivel is 5s,10s ad 19 s, the stess distibutio espectivel is ~ MPa, ~ Mpa, ~ 7 109Mpa Figue - o the 5s, 1s ad 15s alwas cloud the stess ield ad stess distibutio cuve: Whe the weldig speed o 6mm/s ad the weldig time is16.67s. a he stess ield o the weldig time at 5s b he stess ield o the weldig time at 1s c he stess ield o the weldig time at 15s d the stess cuves o weld seam at dieet positios Figue - Weldig speed o 6mm/s o the stess ield ad stess cuves

6 Advaced Mateials Reseach Vols Figue - i thee dieet weldig momets o stess cloud ca be see that whe the weldig speed is 6mm/s, the weldig time espectivel is 5s,1s ad 15s, the stess distibutio espectivel is 590 ~.7 108MPa, ~ Mpa ad96948 ~.7 108MPa. It ca be see i the stess distibutio image, the wok piece stess is lesse whe the time o the begiig, the stess is maimum whe the weldig pocess to the hal. Stess is agai deceases whe the weldig pocess is comig to a ed. I igue -1, - ad - o the stess distibutio cuves, it ca be see i thee dieet weldig o speed, weld dieet locatios o the stess vaiatio ted is cosistet. Ca be see om Figue -4, whe the weldig speed is 5mm/s, the whole weldig stess value is the miimum Figue -4 he speed ad stess compaiso diagam o weld seam at dieet positios Coclusio 1 I this pape we used the ANSYS sotwae which ca be moe accuate simulate the weldig stess ield withi a cetai age ad it has a cetai value to this eseach. he weldig paametes ca be optimied ad the epeimets umbe ca be educe b dieet weldig speed o Numeical Simulatio o weldig stess. I the ale case with high stegth steel 90 o the weldig pocess ma select the weldig paametes: U18V, I140A, V 5mm/s.that based o the simulated stess esult. Reeeces [1] Yu Ya et al. he weldig popet o the high stegth ale case steel 90 i the heav tuck [J]. Mechaical Egieeig Mateials, 008, 8: 5 ~ 55 [] Eage W, sai N S. empetue ields poduced b tavelig distibuted heat souces [J].Weldig Joual.198, 61:46-55 [] Goldak A,Chakavati A ad Bibb M.A double ellipsoid iite elemet model weldig heat souces [Z].IIW Doc,1985. [4] Goldak A,Chakavati A ad Bibb M.A iite elemet model o weldig heat souces[j].met as.1984,115b:99-05 [5] Weldig Hadbook [M], 199 [6] Hoghai Xu. empeatue Field Aalsis o Cotol Valve Based o ANSYS Joual o Liaoig Uvesit o Petoleum & Chemical echolog,009 [7] Yaodog Gao.Simulatio o Weldig Based o ANSYS Uit Bith ad Death [J]echiue RECHULI JISHU YU ZHUANGBEI BVol.1No.1Feb,010

7 Advaced Mateials, CEAM / he Numeical Simulatio o Weldig Stess Field o High Stegth Steel o Ale Case Steel /