Optimization of Conformal Joints in Axial Tension

<p>Electromagnetic forming uses high current to form conductive material. It has been a possible manufacturing technique for joining materials since the 1960s. In the past decade the process has seen a resurgence due to the desire for lightweight manufacturing. The process provides a means to join dissimilar metals, reduce material costs, and the potential for energy savings in manufacturing. One issue that the process faces is the lack of a model to predict the forming process and effectiveness of resulting joints. There has been work done to characterize high strain rate deformation and to couple electro-mechanical systems, but there are still opportunities to provide better and more specific models of joint formation and behavior. A model was developed to describe the process of electromagnetically compressing aluminum tubes onto a steel mandrel. The model was then used to assess potential mandrel geometries for a tensile joint.</p><p>The process of characterizing the joint formation uses a combination of a numerical code to describe the tube compression pressure and an LS-DYNA computer model to describe the tube compression. The resulting conformal joint predicted by the model was experimentally verified and compared to three purposed mandrel geometries. The purposed mandrel designs were an attempt to evenly distribute the tensile load using three gradually increasing groove depths. The simulation then tested the tensile strength of the joints, verified with physical testing, and identified possible improvements in groove design. A test matrix was used to assess the effect of groove radius and groove depth on joint strength. The results showed that, in terms of strength, the groove depth is the most critical dimension and that the groove entry radius had little effect. The final optimized joint had a rectangular groove profile, with a groove entry radius the same size as the depth. The joint evenly distributed the tensile load and was shown to be more resistant to a reduction in friction than previously purposed geometries.</p>

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor dc:publisher

The Ohio State University

Year dc:date

2012

Author dc:creator

• Hansen, Matthew Martin Kenneth

Contributors dc:contributor

• Luscher, Anthony

• Automotive Engineering
• Electromagnetism
• Engineering
• Materials Science
• Mechanical Engineering
• Mechanics
• electromagnetic forming
• EMF
• LS-DYNA
• mechanical joints
• lightweight structures
• joining methods

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=osu1355847865

OAI identifier oai:identifier

oai:etd.ohiolink.edu:osu1355847865