上海交通大学学报

上海交通大学学报, 2023, 57(10): 1329-1336 doi: 10.16183/j.cnki.jsjtu.2022.165

机械与动力工程

铝合金半球壳拉深-旋压复合成形工艺仿真

余小鹏1, 王紫旻2, 于忠奇,1, 罗益民2, 郁立1

1.上海交通大学 上海市复杂薄板结构数字化制造重点实验室, 上海 200240

2.上海航天精密机械研究所, 上海 201600

Numerical Simulation of Stamping-Spinning Hybrid Process for Aluminum Alloy Hemispherical Shells

YU Xiaopeng1, WANG Zimin2, YU Zhongqi,1, LUO Yimin2, YU Li1

1. Shanghai Key Laboratory of Digital Manufacture for Thin-Walled Structures, Shanghai Jiao Tong University, Shanghai 200240, China

2. Shanghai Spaceflight Precision Machinery Institute, Shanghai 201600, China

通讯作者: 于忠奇,副教授,电话(Tel.):021-34206068;E-mail:yuzhq@sjtu.edu.cn.

责任编辑: 王一凡

收稿日期: 2022-05-16   修回日期: 2022-06-18   接受日期: 2022-06-30  

基金资助: 国家重点研发计划(2021YFB3400900)
国家自然科学基金(52175346)

Received: 2022-05-16   Revised: 2022-06-18   Accepted: 2022-06-30  

作者简介 About authors

余小鹏(1998-),硕士生,从事铝合金薄壁构件旋压成形研究.

摘要

针对航天铝合金半球壳传统拉深成形精度差的问题,引入旋压成形,提出铝合金半球壳拉深-旋压复合成形新思路,充分发挥拉深成形和旋压成形的技术优势,实现该构件厚度均匀性好和贴模精度高的成形加工.建立了铝合金半球壳复合成形过程有限元仿真模型,实现了铝合金半球壳复合成形过程仿真,分析了不同旋压占比复合成形件的壁厚分布和贴模度变化规律.结果表明,旋压占比为50%的复合成形铝合金半球壳壁厚均匀性改善明显;强力旋压可改变成形构件应力状态,显著提高复合成形构件尺寸精度.同时,进行了直径1 m级铝合金半球壳复合成形工艺试验验证,实现了构件厚度均匀性和贴模精度的提高.

关键词： 铝合金; 薄壁件; 旋压; 冲压; 成形精度

Abstract

Aimed at the poor accuracy in traditional deep drawing of aerospace aluminum alloy hemispherical shells, and by introducing metal spinning, a stamping-spinning hybrid process strategy for aluminum alloy hemispherical shells is proposed, which can achieve the forming processing of the formed component with a high thickness uniformity and high shape accuracy. The finite element simulation model of the hybrid process of the aluminum alloy hemispherical shell is developed, which realizes the simulation. In addition, the variation law of the wall thickness and shape fitting of the hemispherical shells formed by the hybrid process are analyzed. The simulation results show that the uniformity of wall thickness of the hemispherical shells formed by 50% stamping + 50% spinning is significantly improved. The shape accuracy of the component can be obviously improved by changing the stress state of the forming component by power spinning. Meanwhile, the hybrid process is verified by using an aluminum alloy hemispherical shell with a diameter of 1 m in processing test, which improves the thickness uniformity and the shape accuracy of the hemispherical shell.

Keywords： aluminum alloy; thin-walled part; spinning; stamping; forming accuracy

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本文引用格式

余小鹏, 王紫旻, 于忠奇, 罗益民, 郁立. 铝合金半球壳拉深-旋压复合成形工艺仿真[J]. 上海交通大学学报, 2023, 57(10): 1329-1336 doi:10.16183/j.cnki.jsjtu.2022.165

YU Xiaopeng, WANG Zimin, YU Zhongqi, LUO Yimin, YU Li. Numerical Simulation of Stamping-Spinning Hybrid Process for Aluminum Alloy Hemispherical Shells[J]. Journal of Shanghai Jiaotong University, 2023, 57(10): 1329-1336 doi:10.16183/j.cnki.jsjtu.2022.165

运载火箭铝合金球形贮箱由冲压成形的两个半球壳焊接而成[1],为了减轻贮箱质量,需要在冲压半球壳表面进行铣削加工.生产中半球壳采用多道次拉深+中间退火工艺,拉深件贴模精度差导致后续铣削厚度基准确定难,造成半球壳壁厚均匀性差、结构偏重问题出现.通过增加法向压应力调控变形区应力状态是提升半球壳成形精度的重要途径之一.苑世剑等[2⇓-4]通过充液拉深方法调控变形铝合金应力状态,实现了半球壳精确成形,并在直径3 350 mm箱底上应用.除此以外,强力旋压工艺也可以通过施加法向应力提高成形件贴模精度.旋压成形方法具有工艺柔性高、加工载荷低、制造周期短等技术优势[5],已成为国内外箭体箱底整体化制造的一种方式[6].为此,本文针对铝合金半球壳成形精度差问题,开展基于旋压技术的半球壳成形精度提升方法研究.

旋压成形是机床主轴带动金属板坯和芯模一同旋转过程中侧压旋轮按照设定的加载轨迹将板坯逐渐贴靠芯模表面获得回转薄壁件的工艺方法.对于铝合金曲面薄壁构件旋压成形,国内外目前已开展了相关基础性研究.Gao等[7⇓⇓⇓-11]研究了大型薄壁壳体旋压形成机理与不均匀协调机理,从而确定了成形质量与旋压参数的关系,并建立对应的起皱预测模型;夏琴香[12]对铝合金曲面薄壁构件旋压过程中的有限元建模仿真关键技术进行了详细的研究;Zhang等[13]通过实验和有限元模拟手段,揭示了薄壁封头旋压过程中的起皱机理;林波等[14]采用两轮法旋压成形试验实现了半球壳体多道次普通旋压成形;杜陈阳等[15⇓-17]对铝合金曲面薄壁件旋压中的法兰起皱发生规律进行了研究,并提出了起皱预测模型.除了对成形缺陷的研究,针对铝合金曲面薄壁件旋压成形壁厚均匀性的改善也有诸多研究成果.Biplov等[18]采用数值模拟方法研究了流动旋压参数对于半球形件厚度分布的影响;Jia等[19]分析了不同旋压路径对锥筒组合薄壁件成形性能的影响;宋金龙等[20]提出了基于普旋和剪旋规律的变厚度板坯设计方法,以此来改善半球件的壁厚均匀性;Gan等[21]对多道次普通旋压加工中正程和反程轨迹分别进行了参数化设计,并研究了轨迹关键参数对成形件壁厚的影响.

前期研究表明,半球形件普通旋压成形过程在球形底部存在剪切旋压变形特征,导致球形底部厚度遵循近似剪旋正弦律,减薄率在30%以上.为此,大型半球壳整体成形采用剪切旋压和普通旋压的复合成形技术.相对整体加载的拉深成形而言,半球壳旋压成形件减薄量更大,但也具有更好的成形精度.为此,综合考虑拉深和旋压的技术优势,针对中等规格航天铝合金半球壳提出拉深-旋压复合成形工艺.通过利用两种工艺优势,实现构件壁厚均匀性和轮廓精度协同提升,因只有拉深和旋压工序转换需要中间退火,也提高了加工效率.

1 拉深-旋压复合工艺仿真模型

拉深-旋压复合成形工艺如图1所示,即先将板坯进行拉深到一定的高度,中间退火后再进行旋压成形剩余部分.在半球壳拉深-旋压复合成形中,冲压和旋压两种工艺的分配比例不仅影响着成形件厚度均匀性和贴模精度,还影响着中间退火次数.定义旋压占比为其评价参数,即旋压占比δ为成形件与拉深件高度之差hs占成形件高度ht的比值,如图1所示,并以全尺寸铝合金半球壳为对象,研究该复合工艺中旋压占比对半球壳成形件厚度和贴模度的影响,寻找合适的旋压占比,为航天中小型铝合金半球形件高精度加工提供技术支持.

图1

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图1   铝合金半球壳拉深-旋压成形示意图

Fig.1   Schematic diagram of deep drawing-spinning forming of aluminum alloy hemispherical shell


1.1 有限元模型建立

拉深-旋压复合成形中,板料拉深处于平面应力状态成形,而强力旋压属于板材体积成形.该半球壳使用圆形坯料为直径1 666 mm、厚度8 mm的铝合金退火材料,其屈服强度和抗拉强度分别为75 MPa和170 MPa.考虑到米级薄板坯料尺寸大,三维实体单元精确计算拉深-多道次旋压耗时冗长,本文基于Abaqus/Explicit平台建立了拉深-旋压复合工艺的二维轴对称有限元模型,兼顾了强力旋压阶段仿真精度与多道次全程加工计算效率.

仿真模型中,铝合金板坯假设为各向同性弹塑性材料,板坯的网格类型为CAX4R,控制沙漏效应的四节点缩减积分双线性轴对称四边形,网格尺寸为4 mm;拉深模具和旋压模具均设置为解析刚体.拉深模具的凹模圆角为50 mm,凸模为500 mm半球面;旋压模具的芯模与拉深凸模同尺寸,旋轮圆角半径为50 mm,尾顶直径根据拉深件贴模区域大小进行设计;假设变形铝合金与凸模(芯模)、凹模、压边圈的接触界面为滑动摩擦,摩擦因数假设为0.15,实际压边力对应载荷为2 MPa;而变形铝合金与旋轮的接触界面为滚动摩擦,因数假设为0.02.

为了更好地模拟多道次成形过程中间退火的影响,在每一道次拉深仿真完成后,提取变形板坯的节点位置,对提交文件中的模具位置和板坯形状进行修改,消除板材应力应变场,并进行下一道次成形过程仿真.

在拉深-旋压复合成形仿真时,根据需要调节旋压占比δ.旋轮工艺轨迹按照宋金龙[22]的规划方法进行设计.旋压阶段采用多道次旋压的逐段贴模工艺,旋出轨迹采用凹曲线的线型,旋轮工艺轨迹规划如图2所示.图中:φ为半径与y轴夹角,即母线角度.相邻道次的旋出点角度间隔为10°,根据不同旋压占比增减普通旋压道次数;最后采用强力旋压贴模整形,旋压最大减薄率为原始板坯厚度的12.5%,需要说明的是在最初10° 范围内减薄率逐渐加大至12.5%.

图2

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图2   多道次旋压工艺轨迹设计图

Fig.2   Trajectory diagram of multi-pass spinning process


1.2 有限元模型可靠性分析

现有半球壳拉深工艺涉及多道次成形和中间退火,为了验证所建立模型的可靠性,将全程拉深件壁厚仿真结果与实际测量值进行对比,结果如图3所示.图中:t为壁厚.从图3中看出,壁厚仿真值与实测值分布相吻合,只有在成形件底部仿真误差偏大,最大壁厚偏差约为10%,这可能是实际冲压过程中润滑油涂抹不均匀性造成的.这说明所建立的多道次拉深数值仿真结果是可信的,可为复合成形过程的旋压阶段仿真提供偏差较小的预制坯.

图3

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图3   拉深件厚度对比

Fig.3   Thickness comparison of deep drawing parts


2 拉深-旋压复合成形工艺分析

为了研究拉深-旋压复合过程旋压占比对铝合金半球壳成形精度的影响,获得合适的旋压占比,尽可能减少现有冲压道次,本研究主要讨论旋压占比与壁厚和贴模度的关系.

2.1 旋压占比对壁厚的影响

针对全程拉深(δ=0%)和旋压占比δ=30%,50%,70%以及全程旋压(δ=100%)共5种过程,完成多道次成形数值计算并提取拉深件和旋压件的壁厚分布,绘制出铝合金半球壳成形件壁厚分布曲线图,如图4所示.图中:h为成形件上的点对应板坯初始点到板坯中心的距离.

图4

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图4   复合成形壁厚数值仿真结果

Fig.4   Numerical simulation results of hybrid process of wall thickness


图4(a)为5种成形条件下拉深阶段成形件壁厚分布,图4(b)为后续旋压件的壁厚分布.需要说明的是:在δ=100%仿真中采用强力旋压+普通旋压的复合工艺路径;图4(a)中初始点水平径向距离600 mm处的板坯在拉深过程中位于凹模圆角位置,受到一定的弯曲作用,进而发生一定程度的减薄;初始点水平径向距离700~833 mm的板坯为法兰.从图4(b)可以看出,对于铝合金半球壳全程拉深件,顶部φ≤30° 范围内壁厚减薄较多,φ>30° 后,越靠近端口则壁厚减薄越小,其壁厚最薄处为6.5 mm.因采用复合旋压方式,全程旋压件强力旋压部分构件壁厚减薄较大.δ=30%,50%,70%的半球壳壁厚变化规律相似,这3种复合成形都在20° 附近出现壁厚最薄的区域,超过该区域成形件壁厚有所增加,且在旋压开始后会出现一定程度的二次减薄.对比图4(a)的拉深贴模段可见:拉深部分的构件厚度分布在旋压前后基本一致,这表明在δ≤70%时,旋压加工对拉深件贴模部分的铝合金壁厚影响不大.因此,相对于全程拉深或旋压而言,拉深和旋压复合的成形方法可以提高半球壳壁厚均匀性分布.

为了更好地选择拉深-旋压复合工艺旋压占比,对复合工艺的构件壁厚分布进一步对比研究.可以得出:在球面件的顶部φ≤45°范围内,δ=30%,50%,70%这3种情况的构件壁厚变化规律基本一致,且随着旋压占比的减小,最小壁厚有减小趋势,其中δ=30%对应的构件最小壁厚为6.7 mm,减薄率为16.25%;其他区域(45°<φ≤90°范围),这3种工艺均在引入旋压后出现二次减薄,且减薄程度随着旋压占比的增加而增加.主要原因是:尽管球顶部分完成拉深贴模,然而,因法兰外缘的刚性约束,普通旋压前期仍存在剪切变形成分,造成半球壳壁厚减薄,旋压占比越大,二次减薄越明显.综合得出:δ=30%的半球壳旋压二次减薄较大,δ=70%的半球壳拉深阶段减薄率较大.因此,旋压占比选择过大或过小均会导致构件减薄率过大的情况发生.

综上所述,δ=50%的构件减薄率相对较小,壁厚均匀性更好;从实际工序来看,δ=50%时,此时是实际全程拉深的第一道序,后续两道拉深工序被一道旋压替代,并减少了一道中间退火,缩短了工艺链长度.因此,选择δ=50%的复合成形策略,可以将成形件的最小壁厚控制在7 mm附近.

2.2 回弹量及贴模度分析

对δ=0%,30%,50%,70%共4种工况的回弹进行仿真计算,并提取回弹后构件内表面坐标与理论型面的距离,得到构件贴模间隙曲线,如图5所示.图中:c为成形件的贴模间隙.由图可见:φ≤30° 范围内回弹均较小;30°<φ≤90° 范围内4种方案的贴模间隙呈先增大后减小的趋势,其中全程拉深件在φ≥70° 时出现较大的回弹量,最大贴模间隙值为1.78 mm,其他3种复合成形(δ=30%,50%,70%)成形件贴模间隙走势大致相同,均在φ=70° 附近出现较大回弹,最大间隙值为1.28 mm,相较于全程拉深有明显下降.在3种复合成形中,δ=50%的贴模间隙值相对较大,δ=70%的间隙值相对较小,但是尺寸偏差仍没有明显改善.

图5

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图5   四种方案仿真结果贴模间隙

Fig.5   Simulation results of four schemes for springback clearance


综合考虑壁厚均匀性以及尺寸偏差,选取δ=50%成形方案进行成形件强力旋压,从而提高贴模精度.从上述仿真结果看出:复合工艺在φ≥30°出现较大的贴模间隙.因此.选取强力旋压起始点为 φ=30°,并采取逐渐减薄工艺策略.成形件强力旋压数值仿真结果如图6所示.图6(a)和图6(b)分别为δ=50%成形件强力旋压前后和全程拉深件的壁厚与贴模间隙对比.可以看出:加入强力旋压后,0°≤φ≤30° 的成形件厚度基本没有发生改变,30° <φ≤90°的板坯出现进一步减薄,但是最终稳定在7 mm附近,相比于强力旋压前壁厚更加均匀.成形件在引入强力旋压后构件尺寸偏差更小,贴模间隙控制在0.75 mm以下.相比于全程拉深工艺,复合工艺得到的铝合金半球壳具有更好的厚度均匀性和更小的贴模间隙.

图6

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图6   半球壳强旋阶段数值仿真结果

Fig.6   Numerical simulation results of power spinning stage of hemispherical shell


为了分析复合工艺和全程拉深过程的差异性,对成形完成时板坯中间层的应力(σ)进行提取,得到的应力分布曲线如图7所示.从图7(a)中可以看出,两种方案在经向基本都是拉应力,因此在回弹阶段板材会往半球底部收缩,应力越大收缩的变形量越大.由图7(b)可得,全程拉深件在70°≤φ≤80° 时产生纬向压应力,这导致铝合金半球壳卸载后在这个范围尺寸变动更大,与经向尺寸变动耦合后产生了更大回弹量,造成贴模度差.相比较而言,复合成形件应力变化更加均匀,由于采用了逐渐减薄强旋策略,所以只在30°≤φ≤60° 时纬向应力变化较大.

图7

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图7   回弹前中间层应力分布

Fig.7   Stress distribution of intermediate layer before springback


综合以上研究结果,相较于原拉深工艺,复合成形构件壁厚更加均匀且贴模精度更高,这主要是由于旋压的加入改变了半球壳的应力状态.

3 拉深-旋压复合成形实验验证

为了验证复合成形方法在1 m级铝合金半球壳上的可靠性,进行了退火态铝合金拉深-旋压复合成形试验.先将铝合金板坯在原有的半球壳生产线上冲压50%的高度,即冲压深度为250 mm,随后将退火态半成品工件安装到双旋轮强力旋压机上进行六道次普旋和强力旋压成形,旋压加工现场如图8所示.

图8

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图8   旋压加工现场图

Fig.8   Engineering test of spinning process


试验所制得的半球样件如图9所示.对其4条母线上分别取13个不同测点进行壁厚测量.经过测量,最小壁厚为6.63 mm,高于6.5 mm,达到厚度标准.最小壁厚低于前面仿真结果的原因是:在实际旋压试验时,为了消除二次装夹带来的定位误差,预先对拉深部分进行强力旋压保证工件和芯模紧密贴合,导致该部分厚度的减薄.按实际旋压工艺路线对半球壳成形进行仿真,得到壁厚仿真结果如图10所示.可以看出:仿真值与试验值的分布规律基本吻合,最大壁厚误差为4.5%,从而验证了上述结论的可靠性.另外,从工程应用角度,采用本文数值仿真方法可以获得可接受的计算精度,为大中型球面形构件兼顾精度与效率的旋压过程数值仿真提高了技术性验证.

图9

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图9   半球壳试验件

Fig.9   Work piece of hemispherical shell


图10

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图10   复合工艺成形件厚度对比

Fig.10   Thickness comparison of hybrid process forming parts


随后用圆弧形样板对试验件内表面贴模度进行检验,如图11所示,样板与试验件内表面没有光缝,表明贴合良好,获得了高的轮廓精度.

图11

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图11   试验件贴模情况评估

Fig.11   Evaluation of shape accuracy of work piece


通过铝合金半球壳拉深-旋压复合成形工艺的实施,实现了该构件厚度均匀性和贴模精度的提高,解决了传统单一拉深工艺的不足.同时,中间退火减少至1次,提高了加工效率.

4 结论

针对铝合金半球壳现有制造质量的现状,提出了拉深-旋压复合工艺成形策略,提高成形件壁厚均匀性和尺寸精度.利用有限元方法研究了其改善厚度和精度的可行性,并开展试验验证,主要得到了以下结论:

(1) 基于Abaqus建立了拉深-旋压复合工艺有限元模型,仿真结果表明:旋压占比δ=50%的复合工艺的综合成形效果最优,能有效改善半球壳的壁厚均匀性.

(2) 多道次普通旋压件经过强力旋压改变了端口位置的应力状态,有效提高了半球壳的贴模精度.

(3) 复合工艺试验结果表明,旋压占比δ=50%复合工艺可以获得壁厚和贴模精度满足制造要求的直径1 m级铝合金半球壳.

参考文献

方宝东, 陈昌亚, 王伟, 等.

俄罗斯Fregat上面级

[J]. 上海航天, 2012, 29(3): 34-37.

[本文引用: 1]

FANG Baodong, CHEN Changya, WANG Wei, et al.

Russian Fregat upper stage

[J]. Aerospace Shanghai, 2012, 29(3): 34-37.

[本文引用: 1]

苑世剑, 刘伟, 徐永超, 等.

大尺度非均质壳体流体压力成形机制与缺陷控制方法

[J]. 中国科学基金, 2021, 35(Sup.1): 192-196.

[本文引用: 1]

YUAN Shijian, LIU Wei, XU Yongchao, et al.

Mechanism and defects control of fluid pressure forming for large sized inhomogeneous shell

[J]. Bulletin of National Natural Science Foundation of China, 2021, 35(Sup.1): 192-196.

[本文引用: 1]

YUAN S J.

Fundamentals and processes of fluid pressure forming technology for complex thin-walled components

[J]. Engineering, 2021, 7(3): 358-366.

DOI:10.1016/j.eng.2020.08.014      URL     [本文引用: 1]

刘伟, 徐永超, 苑世剑, 等.

薄壁曲面整体构件流体压力成形起皱机理与控制

[J]. 机械工程学报, 2018, 54(9): 37-44.

DOI:10.3901/JME.2018.09.037      [本文引用: 1]

塑性失稳诱发起皱是制约薄壁曲面构件整体成形的瓶颈问题，通过考虑悬空区反胀效果的曲面薄壳流体压力成形力学分析，推导抑制起皱和破裂的非线性流体压力加载曲线，建立临界起皱应力模型为塑性失稳提供理论判据；在此基础上，针对大型贮箱整体箱底构件流体压力成形起皱预测和控制难题，理论计算大型箱底流体压力成形加载路径，分析流体压力加载路径对反胀区形状、失稳行为和应力分布影响规律，揭示曲面薄壳流体压力成形起皱抑制机理；采用我国自主研制的超大型数控流体压力成形装备（成形力1.5万t/高压液体体积5 m<sup>3</sup>），首次试制出直径3 m级运载火箭燃料贮箱整体箱底，解决了大型超薄（厚径比2‰）曲面薄壳失稳难题。

LIU Wei, XU Yongchao, YUAN Shijian, et al.

Mechanism and controlling of wrinkles during hydroforming of integral thin-walled curved shell

[J]. Journal of Mechanical Engineering, 2018, 54(9): 37-44.

DOI:10.3901/JME.2018.09.037      [本文引用: 1]

Wrinkling induced by plastic instability is a critical problem for the forming of integral thin-walled curved shells. Considering the reverse bulging effect in unsupported area, the mechanical characteristics of sheet hydroforming process is analyzed. Loading paths of liquid pressure about wrinkling and rupture are deduced, a model about critical wrinkling stress is built which can be regarded as a criterion for the plastic instability. Focusing on the forming process of storage tanks of rockets, a theoretical loading path is calculated, the influence of loading path on bulging geometry, instability behavior and stress distribution is discussed. The mechanism of wrinkling suppression is revealed. A large numerical control sheet hydroforming equipment with the biggest power in the world was successfully built (forming power 15000 t, volume of high pressure liquid 5 m<sup>3</sup>). An integral storage tank with diameter of 3m is successfully obtained using the proposed method and equipment. The problem on plastic instability of thin-walled shell (ratio of thickness to diameter equals 2‰) is solved.

周宇, 赵勇, 于忠奇, 等.

交叉内筋薄壁筒体错距旋压成形数值仿真

[J]. 上海交通大学学报, 2022, 56(1): 62-69.

[本文引用: 1]

ZHOU Yu, ZHAO Yong, YU Zhongqi, et al.

Numerical simulation of stagger spinning of cylindrical part with cross inner ribs

[J]. Journal of Shanghai Jiao Tong University, 2022, 56(1): 62-69.

[本文引用: 1]

周磊, 杨国平, 刘凤财, 等.

超大直径贮箱箱底整体旋压成形技术

[J]. 锻压技术, 2021, 46(3): 151-157.

DOI:10.13330/j.issn.1000-3940.2021.03.025      [本文引用: 1]

目前,国内大型贮箱箱底采用瓜瓣顶盖拼焊的方法制造,存在制造可靠性不足、生产效率低等问题。针对大型贮箱箱底制造现状,以某型号运载火箭贮箱箱底作为研究对象,设计了先预成形、后旋压成形的工艺方案,并提出了“一道次剪旋+多道次普旋”的旋压工艺方案,通过有限元仿真分析及工艺试验验证了超大直径贮箱箱底整体旋压成形技术的可行性。结果表明:采用预成形方案能够有效抑制零件边缘起皱,采用剪切旋压与普通旋压相结合的成形工艺能够实现箱底的高精度成形。箱底中心区域采用剪切旋压,构件形状可控性好,模具贴合良好;预成形法兰的边缘区域刚度高,采用多道次普通旋压,既能够达到收边贴模的目的,又能够避免边缘减薄量过大的问题。

ZHOU Lei, YANG Guoping, LIU Fengcai, et al.

Integral spinning forming technology of storage box bottom with super large diameter

[J]. Forging and Stamping Technology, 2021, 46(3): 151-157.

[本文引用: 1]

GAO P F, YAN X G, LI F G, et al.

Deformation mode and wall thickness variation in conventional spinning of metal sheets

[J]. International Journal of Machine Tools and Manufacture, 2022, 173: 03846.

[本文引用: 1]

CHEN S W, ZHAN M, GAO P F, et al.

A new robust theoretical prediction model for flange wrinkling in conventional spinning

[J]. Journal of Materials Processing Technology. 2021, 288: 11684.

[本文引用: 1]

詹梅, 李志欣, 高鹏飞, 等.

铝合金大型薄壁异型曲面封头旋压成形研究进展

[J]. 机械工程学报, 2018, 54(9): 86-96.

DOI:10.3901/JME.2018.09.086      [本文引用: 1]

大型薄壁异型曲面整体构件是航天航空等重要领域迫切需要的高性能轻量化构件。旋压和淬火是实现该类构件整体化制造和性能控制的一种有效途径。然而，大型薄壁异型曲面旋压是多因素耦合作用下的多道次局部加载/卸载复杂过程，成形过程中易出现局部损伤破裂、起皱、隆起、不贴模等缺陷，且旋压后的淬火过程还易造成大的残余应力和淬火变形，并决定着构件的最终使用性能。在建立大型薄壁异型曲面构件旋压和淬火全过程有限元模型的基础上，分析大型薄壁异型曲面构件旋压过程中应力应变分布与变化规律；研究失稳起皱缺陷的形成机理，获得旋压工艺参数对薄壁壳体凸缘周向压应力的影响规律，提出控制凸缘起皱的方法；研究板坯尺寸波动对成形质量的影响；研究获得大型薄壁异型曲面封头旋压件淬火残余应力分布规律和淬火变形规律。

ZHAN Mei, LI Zhixin, GAO Pengfei, et al.

Advances in spinning of aluminum alloy large-sized thin-walled and special-curved surface head

[J]. Journal of Mechanical Engineering, 2018, 54(9): 86-96.

DOI:10.3901/JME.2018.09.086      [本文引用: 1]

Large-sized thin-walled and special-curved surface heads are the urgent needs of aerospace and aviation industry for its high-performance and lightweight. Spinning-quenching is one effective integral forming process to manufacture these components. However, the spinning of large-sized thin-walled and special-curved surface head is one of the complicated local loading/unloading processes under the action of multi-parameters and their coupled effects. In this process, the heads are very prone to produce forming defects, such as local damage rupture, flange wrinkling, local bulge, and unfitting. Additionally, the quenching treatment after spinning will lead to heavy quenching distortion and residual stress, thus seriously deteriorate the material performance. In this work, a finite element model for the whole process of spinning-quenching are established. Based on the model, the distribution and evolution of stress and strain field of the large-sized thin-walled and special-curved surface heads during spinning process is analyzed. In order to obtain the effect laws of process parameters on flange circumferential compressive stress, the mechanism of flange wrinkling is investigated, and a method of controlling the flange wrinkling is proposed. The effect laws of the thickness variation of slabs on deformation quality are investigated. The quenching residual stress and distortion of the large sized thin-walled and special-curved surface heads are also studied.

宋晓飞, 詹梅, 蒋华兵, 等.

铝合金大型复杂薄壁壳体多道次旋压缺陷形成机理

[J]. 塑性工程学报, 2013, 20(1): 31-36.

[本文引用: 1]

SONG Xiaofei, ZHAN Mei, JIANG Huabing, et al.

Forming mechanism of defects in spinning of large complicated thin-wall aluminum alloy shells

[J]. Journal of Plasticity Engineering, 2013, 20(1): 31-36.

[本文引用: 1]

杨合, 詹梅, 李甜, 等.

铝合金大型复杂薄壁壳体旋压研究进展

[J]. 中国有色金属学报, 2011, 21(10): 2534-2550.

[本文引用: 1]

YANG He, ZHAN Mei, LI Tian, et al.

Advances in spinning of aluminum alloy large-sized complicated thin-walled shells

[J]. The Chinese Journal of Nonferrous Metals, 2011, 21 (10): 2534-2550.

[本文引用: 1]

夏琴香. 特种旋压成形技术[M]. 北京: 科学出版社, 2017: 29-96.

[本文引用: 1]

XIA Qinxiang. Special spinning forming technology[M]. Beijing: Science Press, 2017: 29-96.

[本文引用: 1]

ZHANG Y Q, SHAN D B, XU W C, et al.

Study on spinning process of a thin-walled aluminum alloy vessel head with small ratio of thickness to diameter

[J]. Journal of Manufacturing Science and Engineering, 2010, 132: 014504.

DOI:10.1115/1.4000930      URL     [本文引用: 1]

The thin-walled vessel head with the ratio of thickness to diameter less than 3‰ has long been considered to be difficult to be spun because wrinkling is very likely to occur during the thin-walled vessel head spinning process when the thickness is far smaller than the diameter. Based on process experiments and finite element method, the spinning failure of thin-walled vessel head with a small ratio of thickness to diameter is analyzed in the present research. The mechanism of wrinkling is identified and some effective solutions are discussed to prevent the failure. The results show that the feed ratio, the blank geometry, and the roller trajectory are the main factors influencing the spinning qualities. In the shear spinning, the feasible roller feed ratio is found to be within a very small range because of the thin thickness of blanks. Wrinkling will occur if the feed ratio is slightly outside the operation range. Bending the edge of blank or enlarging the blank size can effectively prevent wrinkling at a larger feed ratio, which would increase the operation range of roller feed ratio. Due to the fact that the conventional spinning is a process of multiple passes, there are many factors affecting the forming quality of thin-walled aluminum alloy vessel head. Wrinkling is likely to happen by the influence of roller trajectory in the first pass due to the fact that the thickness of blank is far smaller than the diameter. The straight-line trajectory is the worst trajectory under which wrinkling is most likely to occur.

林波, 谷建民, 周尚荣, 等.

超半球壳体多道次拉深旋压工艺研究

[J]. 机械工程学报, 2011, 47(6): 86-91.

[本文引用: 1]

针对1060超半球壳体基于板坯多道次拉深旋压进行成形性分析，提出两模法和两轮法的旋压成形试验方案，并设计不同旋压试验方案的芯模和旋轮工装。通过MC2000型数控录返旋压机，分别采用R13、R20和R25、R8不同圆角半径的圆弧式旋轮对1060板坯进行两模法和两轮法的多道次拉深旋压成形试验。两模法旋压毛坯件的凸缘边减薄严重，成形效果差；两轮法旋压采用R25旋轮4道次快速进给，R8旋轮4道次中低速精整旋压的旋压工艺，其旋压件贴模度高，成形效果好。试验结果表明：两轮法旋压工艺能实现板坯经多道次拉深旋压成形为超半球壳体。通过降低芯模转速，调整进给比和降低道次减薄率，可以消除旋压成形过程中出现的反挤、波纹和起皮等缺陷。

LIN Bo, GU Jianmin, ZHOU Shangrong, et al.

Research on process of multi-pass draw-spinning of hyper-hemispherical shell

[J]. Journal of Mechanical Engineering, 2011, 47(6): 86-91.

[本文引用: 1]

The formability of aluminum hyper-hemispherical shell deformed from 1060 plates by multi-pass draw-spinning is analyzed. The testing scheme of two-mould and two-roller are proposed, and different mandrels and rollers are designed. Circle-arc rollers of different work-radius test two shaping schemes by MC2000 playback spinning machine. The figuration of two-mould blanks is bad and the thickness of flange is reduced greatly. The figuration of two-roller blanks and inner moulding surface are excellent by the spinning process that the four quick feeding processes of R25 roller and four low feeding processes of R8 roller. The test results show that the figuration of two-roller can shape hyper-hemispherical shell by multi-pass draw-spinning aluminum blanks. Backward extrusion, expansion scab scale and corrugation are controlled by the spinning process of reducing rotational speed of mould, decreasing thinning ratio of pass and adjusting feed rate.

杜陈阳, 孔庆帅, 赵亦希, 等.

薄壁球面构件普旋法兰起皱预测方法评价

[J]. 上海交通大学学报, 2019, 53(4): 431-437.

[本文引用: 1]

DU Chenyang, KONG Qingshuai, ZHAO Yixi, et al.

Evaluation of flange wrinkling prediction methods of conventional spinning for thin-walled spherical components

[J]. Journal of Shanghai Jiao Tong University, 2019, 53(4): 431-437.

[本文引用: 1]

KONG Q S, YU Z Q, ZHAO Y X, et al.

Theoretical prediction of flange wrinkling in first-pass conventional spinning of hemispherical part

[J]. Journal of Materials Processing Technology, 2017, 246: 56-68.

DOI:10.1016/j.jmatprotec.2016.07.031      URL     [本文引用: 1]

万旭敏, 赵亦希, 孔庆帅, 等.

旋压法兰起皱预测

[J]. 上海交通大学学报, 2017, 51(11): 1312-1319.

[本文引用: 1]

WAN Xumin, ZHAO Yixi, KONG Qingshuai, et al.

Research on prediction of flange wrinkling in conventional spinning

[J]. Journal of Shanghai Jiao Tong University, 2017, 51(11): 1312-1319.

[本文引用: 1]

BIPLOV K R, YANNIS P. K, YOSHIO A, et al.

A study of forming of thin-walled hemispheres by mandrel-free spinning of commercially pure aluminum tubes

[J]. Journal of Manufacturing Processes, 2021, 64: 306-322.

DOI:10.1016/j.jmapro.2020.12.036      URL     [本文引用: 1]

JIA Z, YE T, HAN Z R, et al.

Study on die-less spinning of cone-cylinder combined hollow parts

[J]. Journal of Materials Processing Technology. 2019, 271: 488-498.

DOI:10.1016/j.jmatprotec.2019.04.028      [本文引用: 1]

Die-less spinning can achieve the thin-walled parts with the regular shape of cone and cylinder or even some non-axisymmetric shapes. And it has advantages in forming some difficult demolding shapes. In this study, dieless spinning in a cone-cylinder combined hollow part and its forming mechanism were investigated. A ballcrown-shape roller was used to replace a conventional roller in the spinning process. The roller movement and spindle rotation were controlled by a computer numerical control spinning machine to achieve a planned roller path. The pass sets of tilted and horizontal lines were designed to form the cone and cylinder shape, respectively. Further, two methods were adopted to link the two forming pass sets and spin the cone-cylinder combined shape. One is to connect the cone and cylinder forming lines directly (Schemes A); the other is to connect the cone and cylinder forming lines by transition lines (Schemes B). The effects of two key parameters (roller path and feed ratio f) on the wrinkling and wall thickness distribution were analyzed. The product exhibited wrinkling on the wall using the roller path of Scheme A with f = 0.5 mm/r. f affected the occurrence of wrinkling considerably. Larger f made the flatness of the cylinder wall worse, no matter which roller path (in Scheme A or B) was used. When f was set to 0.25 mm/r (f was lower than L-T1 in this study) with a blank thickness of 2.05 mm, wrinkling could be suppressed in the roller path of Scheme A. The product had an increasing thickness distribution on both the cone and the cylinder. The cylinder wall was even thicker than the disk blank with a blank thickness of 2.05 mm.

宋金龙, 赵亦希, 于忠奇, 等.

铝合金封头旋压成形变厚度毛坯设计方法

[J]. 上海交通大学学报, 2017, 51(11): 1304-1311.

[本文引用: 1]

SONG Jinlong, ZHAO Yixi, YU Zhongqi, et al.

Research on design method of variable thickness blanks for aluminum alloy head spinning forming

[J]. Journal of Shanghai Jiao Tong University, 2017, 51(11): 1304-1311.

[本文引用: 1]

GAN T, YU Z Q, ZHAO Y X, et al.

Effects of backward path parameters on formability in conventional spinning of aluminum hemispherical parts

[J]. Transactions of Nonferrous Metals Society of China, 2018, 28(2): 328-339.

DOI:10.1016/S1003-6326(18)64666-7      URL     [本文引用: 1]

宋金龙. 薄壁曲母线件多道次旋压成形精度研究[D]. 上海: 上海交通大学, 2017.

[本文引用: 1]

SONG Jinlong. Study on forming quality of multi-pass spinning of thin-walled curvilinear generatrix parts[D]. Shanghai: Shanghai Jiao Tong University, 2017.

[本文引用: 1]

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