基于AutoForm的后轮罩外板拉伸筋模拟研究

以某车型后轮罩外板为研究对象,对其进行AutoForm分析,研究不同拉伸筋对成型性影响。采用不同形式拉伸筋对成型结果进行优化分析。通过对比分析周圈拉伸筋、分段拉伸筋和双层拉伸筋,并结合失效原因分析,得出对于深拉伸制件,双层拉伸筋更有利于制件成形。     

基于Dynaform的汽车后围板成形过程仿真研究

采用实验和数值模拟法相结合的方法,利用单向拉伸试验测量汽车后围板材料的力学性能,利用数值模拟分析了汽车后围板的成形过程。结果表明,单向拉伸试验所测结果和材料库中参数存在很大差异。数值模拟过程中,为了使材料能够发生充分的变形,拉延筋的设计是很必要的,但是拉延筋的存在并不能完全解决零件破裂问题,可能还有其他的因素导致零件产生破裂趋势。     

压路机前围拉伸模设计

对于拉伸模最大的难度就是要求有合理的工艺方案、良好的工艺补充，只有确定好方案．才能够拉伸出合格的产品。该前围覆盖件拉伸模经过工艺分析，采用1模2件对称方式拉伸。经过CAE拉伸软件的模拟分析，对于拉伸不足的区域采用增加拉伸筋的方式，通过试模最终加工出合格的零件。     

CAE技术在冲压工艺中的应用

简述了CAE技术在汽车覆盖件冲压工艺中的应用,通过对拉伸工序设置等效拉伸筋进行模拟分析,能够提前预知局部成形缺陷,并采取有效措施。实践证明,其分析缩短了模具制造周期,减少了模具试模次数。     

薄板冲压成形中的拉伸筋阻力及其影响因素研究

拉伸筋阻力的形成是一个非常复杂的过程，并受多种因素的影响。通过对板料经过拉伸筋时变形特点的分析，叙述了拉伸筋阻力的形成机理，并在大量实验的基础上获得了各种因素对拉伸筋阻力的影响规律。     

中薄板冲压成形中的拉伸筋阻力及其影响因素研究

通过对铁路货车零部件的中薄板冲压成形中板料经过拉伸筋时变形特点的分析，叙述了拉伸筋阻力的形成机理，并在大量实验的基础上获得了各种因素对拉伸筋阻力的影响规律。     

拉伸筋在盒形件拉伸成形中的应用

用盒形件拉伸成形工艺参数判断油底壳的拉伸成形时,油底壳需要2道拉伸工序成形,拉伸模具增加拉伸筋后,可使油底壳1道工序拉伸成形,并介绍了几种拉伸筋的结构、形状及布置注意事项。     

7B04铝合金带筋构件蠕变时效成形数值模拟与试验

基于7B04铝合金165℃单轴拉伸蠕变试验数据,拟合得到时间硬化本构方程,利用有限元软件ABAQUS对带筋构件的蠕变时效成形过程进行数值模拟,分析筋条的变形规律,并进行验证试验和性能研究。结果表明:筋条的塑性变形有效减小蒙皮的回弹,和蠕变变形共同决定构件外形;数值模拟与试验结果吻合较好,构件95%外形区域的绝对偏差值≤0.50 mm;构件的筋条强度高于蒙皮强度,与无应力时效相比,构件的伸长率降低,电导率升高;应力松弛试样的性能和筋条的性能相近,可以进行等效表征。     

板料成形模拟系统的开发应用

介绍了拥有自主版权的板料成形动力显式有限元模拟系统VIFORM ,其包括基本原理和有关接触搜索、压边力处理、拉伸筋模拟和惯性效应避免等关键技术。最后通过对汽车矩形反光镜、仿车门及方盒的模拟 ,对系统进行了验证     

拉深筋结构参数与约束阻力的回归正交试验

利用拉伸筋试验系统,通过回归正交试验的方法对梯形拉深筋结构参数与拉深筋约束阻力的定量关系进行实验研究,建立了梯形拉伸筋结构参数与约束阻力关系的一次线性回归方程,并对回归方程和偏回归系数的显著性进行了F检验,校验了回归方程的准确性;分析了梯形拉伸筋结构对约束阻力的影响规律:凸筋圆角半径、凹槽半径对约束阻力具有显著性影响,筋高对约束阻力影响不显著。用结构参数实际值与板材厚度t的比值替换回归方程中的试验因素,保证了回归方程的通用性,实现了通过回归方程即可根据梯形拉伸筋结构参数预测出板材通过拉深筋时的约束阻力,为冲压模具拉深筋设计提供了基于实验的可靠依据。     

汽车支架零件模拟分析与工艺结构优化

以汽车支架零件为载体,以一步成形法模拟分析理论为基础,应用AutoForm冲压工艺有限元分析软件,针对典型汽车薄壁件的工艺结构进行压延筋结构与压料面尺寸模拟成形工艺分析。结果表明,控制了材料流动,解决了零件冲压成形工艺过程中的开裂问题,优化了材料片尺寸与压延筋工艺结构,取得了良好的应用效果。     

不同排气塞数量下的泡沫模样的射料充填数值模拟

建立了欧拉/拉格朗日离散颗粒模型,采用数值模拟方法,研究消失模铸造泡沫珠粒射料充填过程中稠密气/固两相流动的流体动力特性。泡沫珠粒的运动与气相压力分布密切相关,泡沫珠粒充填过程中在排气塞附近区域形成型腔内外压力差,是珠粒充填的动力。在其他条件相同时,对3种不同排气条件下的射料充填过程进行了数值模拟,结果表明,排气不畅时射料充填过程持续时间最长,易在型腔内的高压区出现充填不密实的现象。     

基于盒形件拉深成形的激光拼焊板数值模拟研究

为了解决拼焊板覆盖件零件成形过程中焊缝移动以及与此相关的成形性能下降的难题,本文基于静态隐式算法和动态显式算法,分别建立两种不同焊缝模型,通过数值模拟和应力分析得到了焊缝移动规律,获得了焊缝移动量曲线.数值模拟中采用阶梯压边圈,通过对模拟结果的应力、单元厚度分析,比较模拟结果和试验的吻合程度,验证了数值模拟和应力分析的正确性.     

基于Dynaform的激光拼焊板成形性能数值模拟研究

为了解决同种材料、等厚度激光拼焊板在数值模拟研究中如何建立准确的焊缝模型这一难题,通过显微硬度试验测量拼焊板焊接接头焊缝区和热影响区的硬度值,并对这些数据进行分析和计算,得到两个区域的材料力学性能参数,建立焊缝模型,并采用有限元模拟软件Dynaform 5.5对建立的焊缝模型进行数值模拟.通过模拟和试验结果的对比,验证...     

激光拼焊板成形性能的数值模拟研究

在拼焊板的数值模拟研究中,如何建立准确的焊缝模型是一个亟待解决的难题。本文通过对母材和拼焊板进行拉伸实验获得拉伸实验数据,并基于等应变假设条件和力平衡条件方程,计算得到拼焊板焊缝的力学性能参数,建立了4种不同的焊缝模型。采用有限元模拟软件Dynaform,分别对4种不同焊缝模型进行拼焊板杯突试验数值模拟。通过对4种焊缝模型模拟结果中杯突值、开裂位置、主应变和试验得到的相应值进行比较,验证了精确焊缝模型的实用性。     

Formability consideration during bead optimisation to stiffen deep drawn parts

Beads that alter the geometry of sheet parts can increase the stiffness of deep drawn sheet parts. The locations and geometry of the beads have a great influence on the stiffness of the parts. The design of beads is the result of numerous bead optimisations, developed without considering the manufacturability. Therefore, a bead optimisation algorithm should be developed to increase the efficiency of the bead design while simultaneously considering manufacturability. The trajectory generated along the principal direction of bending stress determines the locations of the beads that maximise the stiffness of the parts. Formability is chosen as a criterion that effectively suggests itself for the initial bead geometry during bead optimisation. The influences of the deep drawing depth, initial specimen geometry and bead height on formability are then investigated by means of a sensitivity analysis. The maximum formable bead height as function of pre-strains is derived from this sensitivity analysis using linear superposition and second order polynomial fitting. The initial bead height function will play a crucial role in supplying the initial values and the validity of the simulation model is experimentally confirmed by the chosen bead locations and geometry.     

曲面零件拉深筋的数值模拟

在拉深筋成形能力理论、曲面零件变形计算结果、以及实际板料参数这3种条件的基础上,以拉深筋参数设置为重点,应用有限元分析软件Dynaform,分别在有拉深筋和无拉深筋这两种条件下,对曲面零件进行有限元模拟实验.通过模拟实验对比的结果,显示了拉深筋在曲面零件变形时的作用,使理论计算和模拟实验得到了相互验证.同时,也进行了实验验证,实验结果与计算机数值模拟结果相吻合.此方法在整个加工工艺工程中简便直观,对于实际生产有一定的推广应用价值.     

基于数值模拟的盒形件拉深成形变拉深筋技术研究

以盒形件为研究对象,建立了盒形件拉延筋成形的数值模型,分别对盒形件固定拉深筋和变拉深筋成形进行了数值模拟研究,并进行了工程试验的验证,对结果及误差进行了分析,实现了基于拉深筋高度变化的变拉深筋技术。这种方法能有效发挥板料成形性能,提高零件拉深成形质量。     

A new experimental test apparatus for angle binder draw bead simulations

A novel device for obtaining pulling and holding forces for draw bead tooling on inclined binder surfaces has been developed. A mechanical design featuring two load cells, a male–female draw bead set, translation and rotation degrees of freedom, and a screw-driven clamping system has been incorporated into a standard tensile test machine. On a real time basis, pulling force, holding force, and draw-in displacement are downloaded directly into a PC for data processing. Results for the sheet metal materials considered confirm quantitatively that the binder angle significantly influences the draw bead pulling force. For example, for the materials, bead penetrations, and bead geometries studied, the pulling force at a 20° binder angle ranged from 55% to 96% of that corresponding to a 0° binder angle. The pulling force data are useful for the purpose of theoretical and numerical draw bead model calibration. The proposed experimental system, called the Oakland University Angle Draw Bead Simulation (OU-ADBS) test, represents a significant breakthrough in draw bead simulation technology due to its relatively low cost and clever design.     

Stiffness effect of conductive composite powder on electrical properties of ACF for FPD

Elastic moduli of C/Ps were varied to develop an epoxy-based reparable thermosetting ACF for FPD without causing bounce-up in the contact resistance and fracture of the conductive composite powders (C/Ps). The modification of the elastic properties of the C/Ps was done by modulating of the elastic properties of the Polystyrene (PS) bead that is the core of the C/P. The elastic properties of the PS bead changed by crosslinking degree during seeded emulsion polymerization. A simulation based on the experimental results was done to find the optimum mechanical properties of C/Ps for future finer pitch size application. For better simulation, both cases (with/without consideration of interfacial friction and slip) were compared. From these experiments, the following results were confirmed. C//P stiffness was controlled by a change of cross-linking density of the PS bead. The mechanical behaviors between the C/P and PS bead were similar within error range. When the cross-linking density of the C/P was less than 50%, the C/P could be deformed over 40% without fracture. Also, the ACF with a 50% cross-linking density C/P didnt show any bounce-up in C/Ps contact resistance and fracture. Although differences between the cases (with and without consideration of interfacial friction and slip) were observed, neither case matched the experimental result. For a closer simulation, a variation in factional coefficient is needed.