当前位置:首页 >> 信息与通信 >>

FEM Simulation of Cold Roll Forming in the Car crash beam


FEM Simulation of Cold Roll Forming in the Car crash beam Liu Hua-min1, Liu Zhi-qing1, Zou Zhong-ping2 1. Institute of roll forging technology, Jilin University, Changchun, Jilin 130025,china 2.Hot Rolling Workshop of Strip And Plate Mill, Laiwu Iron and Steel Group Co., Ltd, Shandong Laiwu,271104,china Abstract: The cold roll forming process of car’s rubbing beam was simulated by MSC.Marc. The history-curves of the stress and strain of the special node were obtained and the deformations of the transition zone were analyzed. The simulation results show that as the metal sheet is bending, deformation changed from the elastic to plastic deformation, in each pass, the bending stress increased, then decreased, and after some fluctuation it tends to a steady state, from this point of view, Cold Roll Forming is a multiple loading and unloading process. Keyword: Rubbing beam;Cold roll forming;FEM simulation shown in Figure 1, the material is 20MnCr5 in 1. Introduction The cold-formed steel sections, As an the material library, table 1 shows the economic cross-section, has been used to save mechanical properties of the material. resources by optimizing the cross-sectional According to Roll Forming characteristics, the shapes, rather than simply increasing material cold forming process of car crash beam can usage or improving the material properties, make such a simplification: the rigid roller which makes it own broad application areas, rotates with a constant speed , plate and strip and it has been widely used in automotive, moved to the roll seam with a constant initial aerospace, construction and other velocity, after get into the roll gap, by the [1-3] industries . friction power led strip campaign to complete Cold Roll Forming which involves contact the bite, due to the sheet metal biting into the between the roller and the rolling friction is a process is very complex [7], the contact area of plate front-end and roll groove is very small, process of large displacement and finite strain, relying on friction is very difficult to make Also it is a nonlinear problems such as sheet metal. geometric nonlinearity, material nonlinearity [4-5] The This article uses the following a method to and boundary nonlinearity . deformation process is a the coupling process achieve the sheet metal to bite into the sheet: of lateral bending, lateral torsion, vertical fixed lower roller, the sheet metal placed stretching elastic, elastic-plastic and plastic under the roller, the upper roller downward to deformation, so the simulation analysis of generate sufficient pressure between the [6] sheet metal forming process is very difficult . rollers and sheet, then rollers rotates with a Use of finite strain elastic-plastic finite velocity, and the friction between the rollers element analysis can simulate this process and sheet drives the sheet forward to complete effectively, and provide some theoretical the follow-up forming. Taking into account the guidance for the actual production. symmetry, only half of the models are simulated, as shown in Figure 2. 2. Finite element simulation of cold-forming 2.1 The simplification of simulation model This paper simulated the roll forming process of car crash beam The products is

Fig 1 cold roll forming product Table 1 the mechanical properties of 20MnCr5
Rp0.2 Rm E 530MPa 885MPa 2.1e5MPa ? Δ5 ρ 0.3 13% 7850kg/m3

2.2 Creation of model Rollers use rigid body, there are 16 groups of rollers totally, sheet metal use deformable body, it’s size is 700x112.3x1.6mm, grid cell types are three-dimensional solid element Solid16, using the principle of network structure local refinement, namely, the mesh, in the deformation zones and near the zone, is intensive, but other is sparse, and it satisfies the mesh distortion caused by forming process of sheet metal deformation. Whole piece of sheet metal is a total of 6,000 units, 12462 nodes. At the same time contact analysis function provided by MSC.Marc is used for better coordination on displacement and force transfer of the node in both sides of intensive-sparse grid interface. Finite element model is shown in Figure 2.

position, in addition, due to local deformation is larger, there is some deformation in the edges and the middle part of the sheet. Deformation process from the point of view, in the first-pass, maximum of the equivalent stress is 517.7MPa, close to the material yield stress, sheet mainly occurs elastic deformation, and the value of equivalent strain is small, the maximum is only 0.02084, the stress value is increasing with bending, at the last pass, the value of stress reaches 688MPa, beyond the material yield stress, sheet occurs plastic deformation. Thus, as the conduct of bending, metal sheet bending deformation changes from the elastic deformation to plastic deformation.

Fig 3 the distribution of the equivalent strain in the first pass

Fig 4 the distribution of the equivalent strain in the sixteenth pass

1-8sets of rollers 9-16 sets of rollers Fig 2 FEM model 3. Analysis of simulation results 3.1 Some typical load-step strain and stress distribution Figure 3-6 are taken from horizontal to establish the path node. From the figure we can see that equivalent stress and strain concentrated in the bends in the horizontal

Fig 5 the distribution of the equivalent stress in the first pass

Fig 6 the distribution of the equivalent stress in the sixteenth pass 3.2 The history-curve of stress and strain of Special nodes In order to better show the changes of the stress and strain in deformation process, the following paper analysis the 1-8 passes’ history-curve of the stress and strain of the corner nodes, shown in Figure 7 and 8. From the figure we can see that in each pass deformation, the equivalent stress of the corners increased, then decreased, and after some fluctuation tends to a steady state, from this point of view, sheet occurred once loaded and unloaded through each set of rollers, so Cold Roll Forming is also a multiple loading and unloading process. Equivalent stress decreasing suddenly is due to the nodes of corner parts break away from rollers, the nodes leaved the roll gap, the deformation is no longer subject to the constraints imposed by rollers and elastic recovery occurs, so the stress and strain value decreases, as the distance between the node and the roll gap is farther and farther, elastic recovery is also weaker and weaker, and then the equivalent stress is stabilized. The equivalent strain of the corner nodes is also increasing, variation of the train is simpler than the stress, the difference is that the strain showed a gradual increase process in the ladder-shaped, when the sheet metal left the rolls, the strain has also been reduced, but not significantly.

Fig 7 the history curve of equivalent von miss stress of corner nodes

Fig 8 the history curve of equivalent von miss strain of corner nodes 3.3 Analysis of stress and strain in the transition zone The bending deformation between two rollers is not accomplished for an instant in the cold forming processes, but it requires a gradually forming transition process, so there is a deformation transition zone along the length direction of the sheet. Take transition zone between pass 4 and 5 for example to analysis the stress and strain distribution. Take the node for the path along the longitudinal direction building Figure 9 and 10 in the sheet metal bend, from the figure, we can see that the distribution of equivalent stress and strain of sheet metal transition zone in the length direction is gradually increased along motion of sheet, and the equivalent stress of bending zone between the 2 rolls is larger. It is about 700MPa, far more than the material yield strength, so sheet metal had been occurring plastic deformation in the transitional zone, it will be seen from this that the sheet metal deformation in the transition zone is a joint action of two sets of rollers in the forming process.

Reference [1] Cui Gaojian, Lv Xiangyan zhenghao chi. Cold Roll Forming Cold Roll Forming Section Design of Passes Development. Machinery, 2005, 43(494):41-44; [2] Liu Yang, Xie Weiping. the cold-rolling steel d esign criterion steel structure re view. Steel Construction,2004,(6) :36-39; [3]K. Sweeney, U. Grunewald . The Application of Roll Forming for Automotive Structural arts.J Mater Process Tech, 2003, 132: 9-15 [4]zhang Lipeng, Zhou Hongyu, Liu zhichong. Characteristics and Development of Curved Section Steel of Cold. , China Metal Forming Equipment & Manufacturing Technology,2005,40(2) : 26-28; [5] H.Ona,H. Watari,T. Nakako.Production method on pipe of thin-spring steel sheet,J. Mater. Process. Technol,2001, (115):92–96; [6] Alsamhana, Hartelyb, Pillingerb. P. I. The computer simulation of cold-roll-forming using FE methods applied real time remeshing techniques , Journal of Materials Processing Technol,2003, (142):102–111; [7]Liu Huamin.FEM Simulation in Cold Roll Forming Process of Stainless Steel Corrugated Plate. China Metal Forming Equipment&Manufacturing Technology, 2008:70-72。

Fig 9 the curve of equivalent strain between the fourth pass and the fifth pass

Fig 10 the curve of equivalent stress between the fourth pass and the fifth pass 4 Conclusion (1) In the Cold Roll Forming process, the equivalent stress and strain concentrated in the bends zone in the horizontal position, in addition, there are some deformations in the middle part and edges of the sheet metal. As the rolling proceeds, the deformation of sheet metal bends change from elastic-plastic deformation to plastic deformation; (2) In the sight of characteristic of stress variation of bending zone nodes, cold Roll Forming is a multiple loading and unloading process, sheet metal occurred the elastic recovery through the rollers; (3) In the Cold forming process of car crash beam, there is a transitional zones between two sets of rollers. In this zone, equivalent stress reached a larger value, sheet occurred plastic deformation.


相关文章:
FEM Simulation of Main Deformation during CageRoll-Forming ....pdf
FEM Simulation of Main Deformation during CageRoll-Forming Process_材料科学_...Numerical simulation of cold roll-forming processes. Journal of Materials ...
冷轧带钢拉矫工艺仿真参数修正方法的研究.pdf
andthe width coefftcient KWOSput forward讥FEM simulationincoldrollstriptensionwidthreductionratiowidthreduction specific algorithm WtI¥昏uen.In ordertoillustrate...
冷弯型钢弯圆的设计与有限元模拟.pdf
北京100144)SweepingdesignandFEMsimulationofcold-formedsteeILIHao,JING Zuo-jun,...withtherectangularcold-rollvoid 2 【Abstract】Based on theplasticlargebending ...
锥齿轮精密冷摆辗成形在“材料成型数值模拟”课程教学中的应用_....pdf
G424 Application of Precision Cold Roll Forming of Bevel Gear in the Teaching of “Numerical Simulation of Material Forming” QIAN Dongsheng[1][3], ...
连续辊弯成形过程模拟研究_图文.pdf
辊弯成形的轧 辊FEM模型如图6所示。 杂崔 图3母材试样l双线性模型拟 Fig....Pillinger I The computer simulation of cold-roll-forming using FE methods ...
FEM Simulation of Cold Roll Forming in the Car crash beam_....pdf
FEM Simulation of Cold Roll Forming in the Car crash beam_信息与通信_工程科技_专业资料。FEM Simulation of Cold Roll Forming in the Car crash beam 外文...
roll forming simulation thesis 冷弯的有限元分析论文.pdf
(see Figure 1-a), while in the cold roll forming process; the panel ...implicit and dynamic explicit methods for FEM simulation of sheet forming ...
...re-meshing technique for simulating cold-roll-forming ....pdf
Ahmetoglu, Simulation of roll forming process with the 3D FEM code PAM-...remeshing techniques in the computer simulation of cold-roll-forming, Ph.D....
cold roll-beating.pdf
the cold roll-beating forming technology can not only increase the part ...FEM Simulation of Cold... 4页 2下载券 Roll Gap Crown Adjustm... ...
Advanced_High_Strength_Steel_for_Roll_Forming_图文.pdf
car bodies were built of AHSS the global CO2 ...Simulation Docol Roll 1000 37 Form 04 38 Docol ...beams 45 Key y applications pp 46 Bumper p ...
The Fatigue And Nvh Optimization Of Engines.pdf
Advanced Numerical Simulation Techniques for the ...(FEM) enables detailed information about the ...in the beams - of the crankshaft was the ...
...multi-point forming of thick plates in shipbuilding.doc
FEM to calculate the residual deformation generated...Compared with flame bending, cold forming can ...simulation of shell structures and which permits ...
Process design of the cold forging of a billet by forward and....pdf
numerical simulation of the cold forging operation...One useful application of FEM in the multi-stage... Cold Roll Forming Proc... 暂无评价 9页 免费 ...
FEM STUDY ON THE PENETRATION OF PROJECTILES INTO STEEL.pdf
FEM STUDY ON THE PENETRATION OF PROJECTILES INTO ...cold work hardening and ductility are important ...The simulation of metal forming problems which ...
FEM Simulation of Distortion and Residual Stress Generated by....pdf
//dx.doi.org/10.4236/ojmetal.2014.42004 FEM Simulation of Distortion and Residual Stress Generated by High Energy Beam Welding with Considering Phase ...
...model for the FEM simulation of cross wedge roll_图文.pdf
The coupling thermal mechanical and microstructural model for the FEM simulation of cross wedge roll_机械/仪表_工程科技_专业资料。The coupling thermal ...
电动汽车正面碰撞仿真分析_图文.pdf
andFEMBand boundary conditionwith solvingcontrol...beamalSOwerecarriedon.Inthecrashprocess,the...Tatsuhiro.CrashSimulationof a PassengerCar.SAE952718...
Process simulation and optimization of laser tube bending_....pdf
Laser power, beam diameter, scanning velocity, and scanning wrap angle are ... the FEM process simulation can realize the optimization of forming processes...
...a High Performance Ultrasound Imaging Probe Through FEM ....pdf
(@ -20 dB bandwidth) Beam “steering” ...(stress-charge form): (the superscripts indicates...[MHz] Agreement between FEM simulation and ...
...a high performance ultrasound imaging probe through FEM ....pdf
(@ -20 dB bandwidth) Beam “steering” ...(stress-charge form): (the superscripts indicates...[MHz] Agreement between FEM simulation and ...