Stretch Bending of Aluminum Extrusions: Effect of Geometry and Alloy

An experimental stretch bending study is presented in this paper. A total of 24 tests on 2-m-long rectangular hollow section aluminum specimens are performed in a specially designed stretch bending rig. All tests are carried out with a constant tensile force corresponding to the material's yield stress. Factorial analysis is systematically used in the planning of the experimental program as well as in the result interpretation. Special attention is paid to the influence of the alloy, die radius, and specimen wall thickness on certain response parameters. As stretch bending is an important industrial forming process, die force, sagging, and springback are considered to be the most relevant responses. The tests show that the alloy has the largest influence on the die force and springback, while the sagging behavior is primarily controlled by the geometric parameters (i.e., die radius and thickness).