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摘要：本论文利用DEFORM有限元软件对镦粗变形过程中圆柱体坯料内部孔洞闭合过程进行了模拟研究，并对坯料内部不同位置处及不同形状的孔洞闭合过程进行了计算，得到其闭合规律，定量给出了孔洞闭合时所需的临界变形程度。模拟结果表明：不同位置处孔洞的闭合具有相同的过程，且孔洞尺寸变化与变形程度之间近似成线性关系。随变形程度的增大，孔洞闭合程度均增大，但不同位置处孔洞闭合程度存在差异。对于不同形状的孔洞，四面体孔最难闭合，为所有孔洞闭合所需临界压变形程度的上限值。随后,通过物理实验对上述数值模拟结果进行了验证,模拟结果与实验结果基本一致，从而验证了本文采用的有限元模拟法在分析镦粗变形过程中孔洞闭合方面的可行性和可靠性。6506
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关键词：孔洞缺陷；孔洞闭合；数值模拟；铝合金
Aluminum compression process of closing holes
Abstract：In this paper, the finite element software DEFORM upsetting deformation process billet cylinder internal voids closing process was simulated, and the billet at different locations inside the holes of different shapes and closing process was calculated to obtain its closed rule, quantitatively the hole is closed and the critical degree of deformation. The results showed that: the closed position of holes with the same procedure, and the pore size between the change and the degree of deformation is approximately linear. With the deformation increases, the degree of closure holes are increased, but the degree of closure holes at different locations differ. The different shapes of holes, closed tetrahedral hole difficult, closed holes required for all critical pressure upper limit of the degree of deformation. Subsequently, respectively, through physical simulation and experimental verification of these two aspects of numerical simulation results verify, validate the results are basically the same, which proves this paper, the finite element method in the analysis of the deformation process upsetting aspects of the feasibility and closed pores reliability.
Keywords：Hole defects; Holes closure; Numerical Simulation; Aluminum
目录
1 绪论 1
1.1 铝合金基本简介 1
1.1.1 基本信息 1
1.1.2 铝合金的分类 1
1.2 圆柱形坯料变形过程孔洞闭合的模拟研究 2
1.2.1前言 2
1.2.2镦粗过程中孔洞变形分析 3
1.2.3压下率对孔洞闭合度的影响 3
1.3 DEFORM-3D在模拟金属塑性变形过程中的应用 4
1.3.1发展现状及应用 4
1.3.2 DEFORM-3D 在冷镦方向应用 5
1.4选题的目的和意义 6
1.5 课题的研究内容 7
2 有限元数值模拟及DEFORM简介 8
2.1 引言 8
2.2 有限元数值模拟简介 8
2.3 DEFORM简介 8
2.4 DEFORM软件操作流程 9
3 材料内部孔隙性缺陷闭合的模拟研究 10
3.1 引言 10
3.2 建立有限元模型 10
3.3 数值模拟结果及分析 14
3.3.1 变形程度对镦粗过程中孔洞闭合规律的影响 14
3.3.2 孔洞位置对镦粗变形过程中孔洞闭合规律的影响 17
3.3.3 孔洞形状对镦粗变形过程中孔洞闭合规律的影响 20
3.4 实验验证 22