基于Dynaform的汽车前翼子板拉延成形有限元模拟分析

前翼子板的拉延工艺具有极其复杂的变形规律,运用Dynaform软件建立前翼子板的拉延工艺有限元模型,对拉延成形过程进行数值模拟。结果表明,拉延筋和压边力分布是影响汽车前翼子板成形的主要因素,数值模拟结果满足前翼子板的成形要求。     

三通阀体多向模锻工艺研究

针对三通阀体结构特点和性能要求,采用多向模锻近净成形的工艺方法,利用有限元数值模拟方法得到锻件在成形过程中的网格分布、温度场、应力应变场、载荷曲线等,运用分流成形原理提出一种改进方案,有效降低了合模力,为实际生产提供了依据。     

平板件电磁成形磁场力研究

磁场力分析是电磁成形理论分析的基础，其分析结果直接用于工件的变形分析。应用FEA软件ANSYS对平板件电磁成形磁场进行数值计算，分析了板坯上磁场分布特点及放电电压和脉冲电流频率对磁场力的影响。进行了锥形件电磁成形试验，验证了有限元模拟方法用于平板件电磁成形磁场力模拟的有效性。     

药物片剂压制成形过程的数值模拟研究

运用有限元软件ABAQUS,采用基于扩展的Drucker-Prager的本构模型对药物片剂成形过程进行了数值模拟.获得了药物片剂压制成形的密度分布及成形力等相关数据.结果表明:随着压制深度的增加,片剂材料密度及成形力整体呈现增大趋势.药物片剂压制过程数值模拟得到的片剂材料流动规律及力学行为,将为实际成形中工艺参数的改善...     

平板件电磁成形磁场力研究

磁场力分析是电磁成形理论分析的基础,其分析结果直接用于工件的变形分析.应用FEA软件ANSYS对平板件电磁成形磁场进行数值计算,分析了板坯上磁场分布特点及放电电压和脉冲电流频率对磁场力的影响.进行了锥形件电磁成形试验,验证了有限元模拟方法用于平板件电磁成形磁场力模拟的有效性.     

不锈钢管接头成形过程的有限元模拟与实验研究

根据不锈钢管接头的形状结构特点和材料成形性能，确定该零件可采用正挤压——镦粗二次成形和一次正挤压成形两种工艺进行加工。运用有限元软件Deform-3D对确定的成形工艺过程进行模拟分析，得到金属变形和载荷变化等规律，通过工艺实验，验证模拟分析结果。结果表明：采用正挤压——镦粗二次成形时工艺力较小、变形均匀性好，采用一次正挤压成形工艺力大。     

基于有限元的椭圆件变压边力冲压成形工艺研究

针对椭圆件的形状特点,对变压边力的研究提出了两种方案.运用有限元分析软件Dynaform,通过改变压边圈分区和变压边力方式进行了板料成形性能的有限元分析仿真.对不同变压边力曲线下成形极限图进行了观察,最终确定了较优的变压边力曲线.从模拟结果看,曲率半径较大区域上应该施加递增型的变压边力曲线,曲率半径较小区域上应该施加先减后增型的变压边力曲线.这可以显著提高拉深件的成形极限,且能减少或消除成形过程中出现的起皱、破裂等缺陷.     

粉末烧结体镦粗成形过程热力耦合有限元分析

依据成形中热与力的相互影响,建立了用于模拟粉末烧结材料锻造过程的可压缩刚粘塑性热力耦合有限元列式。对材料为AL6061的粉末烧结体坯料在不同条件下镦粗成形过程进行热力耦合模拟,得到成形过程中的变形、温度以及相对密度的分布状况。热力耦合技术的运用,可以更加精确地描述粉末锻造成形过程,这对确定工艺参数及提高产品质量有重要意义。     

基于板料冲压的压边力拉深成形数值模拟分析

压边力是板料拉延成形过程的重要工艺参数之一,合理控制压边力的大小,可避免成形件起皱或破裂等缺陷.建立了三角冲压件的有限元模型,利用DYNAFORM软件,采用数值模拟的方法研究了三角形冲压件拉深时,压边力随时间及位置变化对成形性能的影响.分析结果表明,通过控制拉深过程压边力值的大小和分布,能有效地控制金属的流动,提高板材的成形性能.     

齿轮粉末锻造的变形力分析及其过程数值模拟

应用粉末烧结材料广义塑性理论,分析和计算了齿轮粉末锻造成形镦粗、复压的变形力和密度,运用MARC有限元数值模拟了粉末锻造齿轮的成形过程,讨论了数值模拟和理论计算结果。     

Sensitivity analysis based preform die shape design using the finite element method

This paper uses a finite element-based sensitivity analysis method to design the preform die shape for metal forming processes. The sensitivity analysis was developed using the rigid visco-plastic finite element method. The preform die shapes are represented by cubic B-spline curves. The control points or coefficients of the B-spline are used as the design variables. The optimization problem is to minimize the difference between the realized and the desired final forging shapes. The sensitivity analysis includes the sensitivities of the objective function, nodal coordinates, and nodal velocities with respect to the design variables. The remeshing procedure and the interpolation/transfer of the history/dependent parameters are considered. An adjustment of the volume loss resulting from the finite element analysis is used to make the workpiece volume consistent in each optimization iteration and improve the optimization convergence. In addition, a technique for dealing with fold-over defects during the forming simulation is employed in order to continue the optimization procedures of the preform die shape design. The method developed in this paper is used to design the preform die shape for both plane strain and axisymmetric deformations with shaped cavities. The analysis shows that satisfactory final forging shapes are obtained using the optimized preform die shapes.     

基于DEFORM的支撑轴挤压凹模有限元模拟分析

借助有限元分析软件DEFoRM对支撑轴挤压过程进行了动态有限元模拟,得到了不同压下量时凹模的应力分布.研究了凹模应力在整个挤压过程中的变化情况,尤其是凹模内壁上的应力分布.为非均布载荷下组合凹模的优化设计和分析提供了依据.     

连续挤压工模具负载的计算机模拟

作为连续挤压成形零件的模具、挤压轮及堵头所受的成形力分析是其进行结构设计的关键。建立了铝合金扁线连续挤压成形的有限元模型,并应用有限元分析软件DEFORM-3D对铝合金挤压的变形过程进行了三维模拟,获得了铝扁线挤压过程中的挤压模具、挤压轮及堵头所受成形力的行程曲线,该行程曲线对挤压机模具、堵头、挤压轮的合理、优化设计提供依据。     

塑料异型材挤出流动数值分析

采用三维有限元数值分析方法,以通用有限元分析软件ANSYS为计算平台,在得出流道内场量分布的基础上,以流动平衡性为评判标准,分析讨论了模具结构对挤出流动的影响以及一些挤出流动规律在挤出成型模具设计中的应用。     

金属板件压接数值模拟及模具设计

以有限元分析软件ANSYS为平台,基于弹塑性有限元理论建立压接模具和板件的有限元模型,对金属板件压接过程中的应力场和应变场进行计算。通过模拟结果与试验结果的比较,证实了采用ANSYS数值模拟对压接模具进行优化设计的可行性,同时研究了影响连接强度的模具设计参数。     

基于有限元分析的汽车覆盖件模具设计

介绍了在有限元模拟基础上进行的汽车覆盖件模具设计 ,利用商业化软件AutoForm实现了模具压料面、工艺补充面以及拉伸筋设计和覆盖件成形过程模拟。改变了传统的在有限元模拟后依靠CAD软件进行频繁模具改进的方法 ,在有限元软件内部实现了模具的参数化设计 ,既缩短了模具设计时间 ,又提高了模具设计可靠性     

Sensitivity analysis based preform die shape design for net-shape forging

A sensitivity analysis method for preform die shape design in net-shape forging processes is developed in this paper using the rigid viscoplastic finite element method. The preform die shapes are represented by cubic B-spline curves. The control points or coefficients of B-spline are used as the design variables. The optimization problem is to minimize the zone where the realized and desired final forging shapes do not coincide. The sensitivities of the objective function, nodal coordinates and nodal velocities with respect to the design variables are developed in detail. A procedure for computing the sensitivities of history-dependent functions is presented. The remeshing procedure and the interpolation/transfer of the history-dependent parameters, such as effective strain, are stated. The procedures of sensitivity analysis based preform die design are also described. In addition, a method for the adjustment of the volume loss resulting from the finite element analysis is given in order to make the workpiece volume consistent in each optimization iteration. The method developed in this paper is used to design the preform die shape of H-shaped forging processes, including plane strain and axisymmetric deformations. The results show that a flashless forging with a complete die fill is realized using the optimized preform die shape.     

A three-dimensional steady-state finite element analysis of square die extrusion by using automatic mesh generation

Steady-state finite element analysis is made for three-dimensional hot extrusion of sections through square dies by using an automatic mesh generator which can generate three-dimensional meshes by shifting two-dimensional meshes. In industrial practice, the design of extrusion dies is still an art rather than science, especially for complicated profiles, because the die design for a new extrusion is developed from previous experience and in-plant trials. The objective of this study is to develop a steady-state finite element method for hot extrusion through square dies, and to provide a theoretical basis for an optimal die design and process control for the extrusion technology. In the present investigation, steady-state assumption is used for both the analyses of deformation and temperature. The analysis of temperature distribution includes heat transfer, and is carried out by decoupling from the analysis of deformation. Convection link element is adopted for the heat transfer analysis between the billet and the container, and also between the billet and the die. Computations are carried out for solid and hollow extrusion of several sections. The present method of analysis has been shown to provide good results comparable with the non-steady-state method with reduced computation time. Distributions of temperature, effective strain rate, velocity and mean stress are discussed for effective design of an extrusion die.     

材料塑性成形过程最优化设计—─灵敏度分析方法在模具设计中的应用

本文在已发表的基于有限元灵敏度分析的模具形状优化设计方法一文的基础上, 给出这一方法的具体应用技术。介绍有限元灵敏度分析和模具形状优化设计的步骤; 讨论网格再划分技术以及灵敏度参量的数据传递; 提出解决有限元分析大变形问题的体积损失问题的方法及其与优化迭代收敛性的关系。最后应用该灵敏度分析方法对锻造过程进行模具形状优化设计。设计结果表明, 采用优化设计的预锻模具所得到的终锻件形状与所要求的理想终锻件形状十分接近。     

型材挤压模工作带长度设计计算的数学建模

本文采用有限元方法 ,以型材挤压过程的有限元模拟为基础 ,研究了局部挤压比、挤压带面积和模孔距离对金属流动速度的影响 ,获得了型材挤压过程的变形流动规律。并综合主要模具结构参数对金属流动速度的影响 ,建立了铝型材挤压模模孔工作带设计计算的数学模型。选择实际型材零件按本文推导的公式设计了工作带长度 ,并与实验进行了验证 ,结果表明挤压效果良好。该公式可用于铝型材挤压模工作带长度设计计算