Hydroforming of Aluminum Tubes for Automotive Applications

汽车应用铝管液压成形

• 批准号: 0140599
• 负责人: Stelios Kyriakides
• 金额: $ 29.98万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0140599&HistoricalAwards=false
• 关键词: Hydroforming; Aluminum; Tubes; Automotive; Applications

Hydroforming is a relatively new process for shaping tubular components out of metals. A simple tube can be hydroformed into a fairly complex shape suitable for use as a frame for a structural component. A tube is placed between two half dies and then pressurized internally. It expands, comes into contact with the dies and is forced to conform to their shape. The simple radial expansion of the tube can lead to a number of defects, with a major concern being thinning of the expanded wall. This can lead to tube burst. In order to reduce thinning, the burst strain can be increased by axially feeding undeformed material into the dies from the two ends using actuators. However, the extent of the developed axial compression in limited by buckling and wrinkling and by friction. Thus, for every part, a working envelope in the axial feed-pressure plane must be established which is free of these modes of failure. While aluminum in tube form is ideal for hydroforming, it is less ductile than steel and has more complex constitutive behavior, which make the hydroforming working envelope tighter. This need for a better understanding of processing control coupled with the empirical manner in which the dies and the process have been designed, have not allowed wide use of hydroforming for aluminum components. The objective of this three-year project is to develop a scientific basis for establishing the working envelopes of the process parameters. The problem will be tackled in a three prong manner consisting of hydroforming experiments, development of constitutive models for appropriate aluminum alloy extruded tubes, and development of several levels of numerical models for analyzing hydroforming and establishing its limits. An important component of the project is a custom hydroforming facility, which will be fabricated and used to study the process parametrically. Alcoa and GM will be act as industrial partners to the project and will interact with graduate and undergraduate students on a regular basis.

水理是从金属中塑造管状成分的相对较新的过程。简单的管可以被水理成一个相当复杂的形状，适合用作结构成分的框架。将管子放置在两个半模具之间，然后在内部加压。它扩展，与模具接触，并被迫符合其形状。管子的简单径向膨胀会导致许多缺陷，主要问题是扩张的壁变薄。这可能会导致管爆裂。为了减少稀疏，可以使用执行器将未变形的材料从两端的模具中添加到模具中来增加爆发应变。然而，在屈曲和皱纹和摩擦的限制下，开发的轴向压缩程度限制。 因此，对于每个部分，都必须建立轴向进料平面中的工作包络，这没有这些失败模式。虽然管形式的铝非常适合氢化成型，但它的延展性较小，并且具有更复杂的组成型行为，这使得水样的工作包膜更紧密。这种需要更好地理解加工控制的需求，再加上设计模具和过程的经验方式，不允许广泛使用用于铝制组件的水理。这个为期三年的项目的目的是建立科学基础来建立过程参数的工作信封。该问题将以三个插脚方式解决，该方法包括水理实验，开发适当的铝合金挤出管的组成型模型，以及开发几个数值模型，用于分析水平成型并确定其限制。该项目的重要组成部分是定制的水理设备，该设施将被捏造并用于参数研究过程。 Alcoa和GM将担任该项目的工业合作伙伴，并定期与研究生和本科生互动。