Towards Further Understanding of the Mechanics of Tube Hydroforming
The objective of this work is to shed some further understanding into the mechanics of tube hydroforming. Initially this process was developed with the philosophy of forming the tube around the pure shear line, such that the deformation can be obtained with the least changes in thickness. To design a process to achieve this intent is very challenging, considering the complex shapes that are designed. The work starts by examining some simple geometries to provide an understanding and a methodology for the process design. It is shown that by changing the amount of material feed in, the part can be made to split, wrinkle or form around the pure shear line, and hence with the least thinning at the areas of interest. The work also confirmed that the material r value has a major impact on the ability of the material to maintain its thickness in this process; the higher the r value, the better the formability and the less changes in thickness.