汽车B柱Rollforming成型的有限元仿真

在汽车车体构件制造中的辊弯成型工艺应用项目研究中,利用大型非线性有限元分析软件MSC.Marc研究了汽车B柱变截面辊弯成型仿真的有限元建模方法,主要包括板料模型和成型辊模型的建立、单元选择、边界条件、各种参数的设置及成型辊的速度加载等内容,然后采用刚性轧辊沿板料长度方向平动的方式对板料成型过程进行仿真模拟,分析了板料在...     

槽钢辊式冷弯成型孔型设计

以槽钢辊式冷弯成型理论分析为基础,论述了槽钢辊式冷弯成型的孔型构成及孔型尺寸的确定方法。此孔型成型法在实际中的应用证明了该方法的有效性。     

基于CCD的应变测量系统在辊弯成型中的应用研究

介绍了自行研制开发的CCD应变测量系统基本原理。通过辊弯成型试验,并与msc．marc有限元仿真结果进行比较,验证了结果的有效性,为辊弯成型应变测量提供了一种可行的的方法。     

冷弯中梁轧辊孔型的计算机辅助设计

介绍了铁道货车用冷弯中梁成型与普通冷弯型钢成型的不同之处,分析了冷弯中梁的设计难点及解决方案.给出了冷弯中梁的成型原理、成型道次分配及孔型尺寸的确定方法.建立了数学模型;并应用计算机辅助孔型设计计算了冷弯中梁各架次孔型尺寸;进行了孔型优化.对冷弯中梁辊式成型的轧辊结构进行了设计.     

外卷边槽钢辊弯成型过程模具的设计及可靠性分析

根据弹性变形和塑性变形的基本原理,利用ANSYS有限元软件对冷弯型钢外卷边槽钢辊弯成型过程进行模拟,并分析了成型过程中各种型材工艺参数对板材冷弯的影响。该分析不仅可以充实辊弯成型理论,同时对设计新的辊弯模具及模具优化具有促进意义。     

冷辊轧成型的弯扭曲校正

在冷辊轧成型加工中,由于设备加工和安装误差,工件产生弯扭曲变形是不可避免的。故常在辊轧机出口处增加校正装置,以防止变形。本文介绍了在轻型辊轧机上,不改变设备结构,利用轧辊对弯扭曲的影响进行校正的方法。一、辊轧机简介辊轧机以10kW电机为动力,装有8组轧辊,前两组为导向输送轮,3～7组为成型轮,第8组为定形     

挤压-弯曲一体化成型铝合金弯曲型材的质量与性能

通过改造传统挤压机,增加弯曲装置,对铝合金型材进行挤压-弯曲一体化成型,研究了辊轮半径和辊轮移动速度对成型质量的影响,基于有限元模拟获得了辊轮半径和辊轮移动速度等最佳工艺参数。结果表明:当型材挤出速度与辊轮移动速度相同时,铝合金型材的成型性较好;挤压-弯曲一体化成型工艺避免了传统拉弯工艺存在的回弹、表面划伤和截面变形等缺陷,提高了弯曲型材力学性能的均匀性。     

一种用于电力二次设备机柜的冷辊弯型钢

首先概括介绍了冷弯型钢辊轧成型工艺,其次着重阐述了一种电力二次设备机柜冷辊弯型钢结构设计,并进行了全面的刚强度计算分析,分析表明,此冷辊弯型钢完全满足性能需求,同时对采用此冷辊弯型钢加工的机柜进行静载荷及动载荷试验验证,从而在理论和实践上验证了此冷辊弯型钢的合理性和可行性,为今后电力二次设备机柜及冷弯辊轧类产品设计、制造提供了经验.     

矿用W钢带多道次辊弯成型数值仿真

矿用W钢带作为一种新型的支护材料,与锚杆结合广泛用于矿井下巷道工作面、切眼、峒室及其他不稳定围岩。随着有限元理论研究的深入,运用弹塑性有限元法,采用大位移和大变形理论,对辊弯成型过程的数值模拟与分析。通过计算得到了矿用W钢带的尺寸参数,基于非线性有限元Marc建立了W钢带成型模型,对其多道次辊弯成型进行了仿真模拟分析,并与实际比较,验证了数值模拟的可靠性。重点分析了钢带成型时弯角处的应力应变,回弹,各道次板宽变化,摩擦系数和辊压力等关键问题,为W钢带成型提供理论依据,对多道次辊弯成型具有一定的参考价值。     

辊弯成型工艺分析及优化方法研究

依据辊弯成型原理,对辊弯成型过程进行工艺分析,进而寻求工艺优化方法,为生产实际提供技术支持.     

基于DEFORM-3D的花键成形分析

基于刚塑性有限元法基本理论,并借助于通用三维有限元分析软件DEFORM-3D建立了花键冷滚压成形全过程三维动态有限元模型,对花键冷滚压成形过程进行了有限元模拟分析。揭示了花键冷滚压成形过程的等效应力、等效应变的分布情况和金属流动规律,从而为花键冷滚压成形工艺研究提供理论依据。     

单轴柔性滚弯成形的有限元分析研究

利用弹性介质(聚氨酯橡胶)对钣金件进行单轴柔性滚弯成形是一种先进的钣金制造工艺。论文介绍了单轴柔性滚弯的工作原理,同时,将大变形弹塑性有限元引入单轴柔性滚弯成形领域,利用高级非线性有限元软件MSC/MARC,建立了单轴柔性滚弯挤压矩形管成形过程的三维有限元模型,成功模拟了板料滚弯成形及回弹的实际过程,对工件滚弯成形过程的主要影响因素进行了分析,获得了滚轴的压入量、橡胶硬度、滚轴直径与回弹后工件的曲率半径之间的关系曲线。     

三辊非对称滚弯成形的数值仿真及试验验证

基于有限元法对三辊非对称滚弯成形工艺进行了研究,对比分析了三辊非对称滚弯成形和三辊对称滚弯成形过程中,变形区应力场、板材上表面的塑形应变场及卷制力的变化规律。仿真结果表明：侧辊位移进给量相同的工况下,三辊非对称滚弯成形的卷制力大于三辊对称滚弯成形的卷制力;三辊非对称滚弯变形区的纵向应力和径向应力均大于三辊对称滚弯成形的纵向应力和径向应力;三辊非对称滚弯成形板材压弯段的成形质量高于三辊对称滚弯成形的成形质量。最后,经三辊非对称滚弯试验验证,有限元模型的成形误差为6.8%,有较高的精度。     

方矩形管连续辊弯成形过程的变形和应力场

应用三维大变形弹塑性有限元法,对方矩形管连续辊弯成形过程中金属流动规律以及应力分布进行了模拟分析.考虑了各道次之间的数据信息传递,保证了下一道次变形历史的延续,从而真实模拟了方矩形连续辊弯成形过程.获得的结果对连续辊弯成形中的产品质量的控制和孔型的优化有着重要意义.     

Finite element simulation of flexible roll forming with supplemented material data and the experimental verification

Flexible roll forming is a promising manufacturing method for the production of variable cross section products. Considering the large plastic strain in this forming process which is much larger than that of uniform deformation phase of uniaxial tensile test, the widely adopted method of simulating the forming processes with non-supplemented material data from uniaxial tensile test will certainly lead to large error. To reduce this error, the material data is supplemented based on three constitutive models. Then a finite element model of a six passes flexible roll forming process is established based on the supplemented material data and the original material data from the uniaxial tensile test. The flexible roll forming experiment of a B pillar reinforcing plate is carried out to verify the proposed method. Final cross section shapes of the experimental and the simulated results are compared. It is shown that the simulation calculated with supplemented material data based on Swift model agrees well with the experimental results, while the simulation based on original material data could not predict the actual deformation accurately. The results indicate that this material supplement method is reliable and indispensible, and the simulation model can well reflect the real metal forming process. Detailed analysis of the distribution and history of plastic strain at different positions are performed. A new material data supplement method is proposed to tackle the problem which is ignored in other roll forming simulations, and thus the forming process simulation accuracy can be greatly improved.     

Simulation and experimental verification of flexible roll forming of steel sheets

Roll forming is a sheet metal forming process that has been used for decades. Usually roll-formed sections have a constant cross section. Flexible roll forming is a brand new forming process that produces parts with variable cross sections, in which the rollers translate back and forth in a direction that is perpendicular to the sheet feeding direction. Theoretical analysis gives an explanation of the plane strain state, compressive stresses, tensile stresses, and shear stresses in flexible roll forming. In order to analyze the mechanics and the deformation characteristics of flexible roll forming, the finite element method (FEM) model of a 17-step flexible roll forming process is established. The yield criterion used in the FEM simulation is Hill 48, and the parameters of which are solved with the yield stresses under different loading conditions and are firstly verified with a plane strain tensile test. The complicated roller paths are realized with data extracted from the computer-aided design (CAD) files with VC++ programs developed by the authors. We developed the first flexible roll forming prototype machine in China, with which the roll forming experiment of a side door beam is performed. Final shapes of the experimental and numerical results are compared. It is shown that the numerical results based on Hill 48 yield criterion that is solved with yield stresses agree well with the experimental results, which indicates that the simulation model can well reflect the real forming process. Detailed analysis of the distribution and history of plastic strain, longitudinal strain, shear strain, and thickness of both the constant cross section and the variable cross section is performed, which is of great help to understand this forming process.     

成形法制备半蜂窝波形条的有限元模拟

航空工业上采用的以成形法成形半蜂窝波形条的方式,成形的波形条结构均匀、精度高、工艺间单.根据某厂生产波形条的工艺,利用非线性有限元法开发了成形法的有限元模型,运用该模型对现场的实际成形过程进行仿真计算,得到与现场实测相吻合的结果.比较板坯在单、双主动辊加栽的条件下,成形结果的优劣性.在此基础上,对影响成形结果的主要因素进行分析.     

铝带坯连续铸轧过程热力耦合有限元分析

根据铝带坯连续铸轧过程瞬态凝固、流变成形的特点,同时考虑影响辊套与铸坯传热界面的接触热导问题,建立了铝带坯连续铸轧过程热力耦合有限元分析模型。在对AN SYS有限元分析软件进行二次开发的基础上,探索了适合于铝带坯连续铸轧这一复杂多重非线性问题热力并存耦合分析的途径,得到了铝带坯连续铸轧过程的温度场及应力-应变场的分布规律。仿真分析结果与实测结果进行了对比分析,二者基本相符。     

Analytical modeling and numerical simulation for three-roll bending forming of sheet metal

The three-roll bending forming of sheet metal is an important and flexible manufacturing process due to simple configuration. It is suitable for forming large sheet parts with complex, curved faces. Most researches on roll bending forming of large workpiece are mainly based on experiments and explain the process through macroscopic metal deformation. An analytical model and ABAQUS finite element model (FEM) are proposed in this paper for investigating the three-roll bending forming process. A reasonably accurate relationship between the downward inner roller displacement and the desired springback radius (unloaded curvature radius) of the bent plate is yielded by both analytical and finite element approaches, which all agree well with experiments. Then, the three-roll bending forming process of a semi-circle-shaped workpiece with 3,105 mm (length)?×?714 mm (width)?×?545 mm (height) is simulated with FEM established by the optimum tool and process parameters. Manifested by the experiment for three-roll bending forming of this workpiece, the numerical simulation method proposed yields satisfactory performance in tool and process parameters optimization and workpiece forming. It can be taken as a valuable mathematical tool used for three-roll bending forming of large area sheet metal.