铸态7075铝合金筒形件强力热反旋基于鼓包的成形极限研究

发布时间：2018-03-02 20:21

  本文选题：铸态7075铝合金　切入点：筒形件　出处：《南昌航空大学》2017年硕士论文　论文类型：学位论文

【摘要】：铸态7075铝合金薄壁筒形件由于具有质量轻、强度高和耐腐蚀强等优点,广泛应用于航空航天等技术领域。多道次强力热反旋成形是加工此类薄壁筒形件的最有效方法之一。然而,鼓包是筒形件旋压过程中常见的缺陷之一,它严重制约着筒形件成形质量和成形极限的提高。为此,本文采用均匀正交试验,针对该筒形件进行了多道次强力热反旋有限元数值模拟。并结合旋压实验,对该筒形件旋压过程基于鼓包的成形极限进行研究。主要的研究内容和成果如下:(1)本文基于ABAQUS/Explicit有限元平台,完善了已有的铸态7075铝合金筒形件多道次强力热反旋三维热力耦合弹塑性有限元模型。(2)采用方差分析法对均匀正交试验数据进行处理分析,并考虑到工艺参数与鼓包高度耦合的关系模型和鼓包极限预测模型的建立,每一道次均取影响鼓包较大的3个工艺参数。影响筒形件第一、二、三、四道次鼓包高度的显著性工艺参数依次取为:sv、mT、s?;mT、mn、(35)t;(35)t、sv、mT;sv、mn、mT。(3)采用极差分析法对均匀正交试验结果进行处理分析,并对比分析验证性试验结果,获得各道次最优工艺参数组合:在第一道次,压下量(35)t取2.4mm,芯模预热温度mT取220℃,芯模转速mn取3.0r·s-1,旋轮进给速度sv取0.6mm·s-1,芯模与工件间摩擦m?取0.15,旋轮与工件间摩擦s?取0.35。第二、三、四道次的(35)t、mT、mn、sv、m?、s?分别取值:2.4、200、3.5、0.8、0.15、0.30;1.9、100、4.0、0.6、0.15、0.35;1.4、100、4.0、0.6、0.20、0.45。(4)基于对筒形件鼓包影响的显著性工艺参数,建立了各道次工艺参数与鼓包高度耦合的关系模型,推导出了各道次鼓包极限预测模型。获得工艺参数对各道次鼓包极限的影响规律:第一道次鼓包极限随着sv的增大先减小后增大,随着s?的增大而增大;第二道次鼓包极限随着mn的增大先减小后变化不大,随着(35)t的增大而减小;第三道次鼓包极限随着(35)t的增大先减小后增大,随着sv的增大而增大;第四道次鼓包极限随着sv、mn的增大均先减小后变化不大。此外,还建立了筒形件各道次鼓包极限图。
[Abstract]:The as-cast 7075 aluminum alloy thin-walled cylindrical parts have the advantages of light weight, high strength and strong corrosion resistance. It is widely used in aerospace and other technical fields. Multi-pass hot reverse forming is one of the most effective methods to process this kind of thin-walled cylindrical parts. However, the drum is one of the common defects in the spinning process of cylindrical parts. It seriously restricts the improvement of forming quality and forming limit of cylindrical workpiece. In this paper, the finite element numerical simulation of multi-pass strong thermal counter-rotation is carried out for the cylindrical part by uniform orthogonal test, and combined with spinning experiment, The forming limit of spinning process based on drum is studied. The main research contents and results are as follows: (1) this paper is based on ABAQUS/Explicit finite element platform. In this paper, the existing finite element model of multi-pass strong thermal inverse rotation three dimensional coupled elastoplastic finite element method for as-cast 7075 aluminum alloy cylindrical parts is improved. The uniform orthogonal test data are processed by variance analysis method. Considering the relationship between the process parameters and the height coupling of the bulge and the establishment of the model for predicting the limit of the bulge, the three technological parameters affecting the bulge are taken for each time, which affect the first, second, and third parts of the cylindrical part. The significant technological parameters of the height of the four times of bulging were taken as: 1% svvm TX? The uniform orthogonal test results were processed and analyzed by using the range analysis method, and the results of the validation tests were compared and analyzed. The optimum technological parameters of each pass were obtained: in the first time, the reduction of 35 t was 2.4 mm, the preheating temperature of the core mould was 220 鈩，

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