## ANSYS金属挤压成形数值模拟研究

本课题将利用有限元法，并通过ANSYS软件研究铝合金棒挤压成形过程，模拟摩擦系数与凹模半锥角变化时铝合金固态金属挤压过程中的应力场和速度场，以获得规律性的结论为生产实践作出指导。结果表明：在挤压过程中，内层金属的平均流动速度要高于外层金属。当摩擦系数增加时，坯料的轴向、径向、周向的拉、压应力峰值都增加，造成挤压后成品的残余应力增加，坯料的等效应力峰值变化不明显。模具的最大等效应力值要远远大于坯料的值。当凹模半锥角增加时，模具的最大等效应力有上升趋势，但在5.7°左右时，凹模的最大等效应力有最小值，此时为最适合的挤压条件。

Title      Aluminum Alloy Rod Extrusion Forming Numerical simulation

Abstract
With a stronger social consciousness of sustainable development,industries have a higher request on energy-efficient and environment-friendly.Since its light weight,high strength,corrosion resistance,excellent mechanical performance and easy recovery which traditional materials don’t have,nowadays, aluminum alloy is more and more important and widely applied in aerospace,communications,industrial machinery,construction and metallurgy.
My topic is focus on numerical simulation of aluminum alloy rod extrusion.With the modeling and simulation by ANSYS, I make research on transient stress field and velocity field in different condition to find basic principles on aluminum alloy extrusion. The result shows, in extrusion process, the average flow rate of inner metal is higher than the outer ones.With friction coefficient increasing, the max value of X-component, Y-component and Z-component stress increase, which would cause residual stress increasing after extrusion.The max Von Mises stress of die is much higher than the value of blank, and it is insensitive to friction coefficient. With the angle increasing,the max value of Von Mises stress on die increases, however, it has a min value when the angle is around 5.7 degree, which means extrusion with 5.7 degree is the best working condition.
Keywords  Aluminum alloy rod  extrusion forming  numerical simulation  stress field velocity field

1 绪论 1
2  挤压原理及铝合金挤压发展概况  2
2.1 挤压技术及其发展概况 2
2.2  铝型材挤压挤压加工工艺的基本原理及特点 3
2.3 铝型材挤压成型过程数值模拟研究现状  3
3  有限元数值模拟原理及发展概况  5
3.1 有限元法的基本思想 5
3.2  有限元法的发展过程 5
3.3  有限元法中的非线性问题5
3.4  状态非线性问题的特点和其ANSYS分析方法6

4  铝合金棒挤压实验及分析 8
4.1  挤压过程参数描述 8
4.2  问题分析 9
4.3  模拟步骤9
4.4  实验结果13
4.5  结果分析37

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