Comparison of Bulge Test vs. Conical Expansion Test for Hollow Extruded Profile Characterization

Abstract:

An experimental campaign on a tubular hollow profile, extruded in industrial environment at two ram speeds, was performed to compare two testing methodologies used for the assessment of the seam welds strength: the cone expansion and the bulge tests. In the former, a cone-shaped punch is driven into the tube causing the expansion till the specimen fracture; in the latter, an internal rubber plug is used to expand the specimen allowing to apply an hydrostatic tensile state. Results and repeatability of the two tests were analyzed in terms of loads and tube radius elongations at fracture; location and morphology of the fracture were also inspected. In each condition, and for both tests, ductile fractures appeared at seam weld location. The bulge test showed a significant reduced data scattering if compared to the cone test and provided more conservative outcomes in terms of elongation at fracture; in addition, it marked more prominently the effect of the increased ram speed that promoted a weld strength decay.

• Periodical: Key Engineering Materials (Volume 585)
• Pages: 111-119
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.585.111
• Online since: December 2013
• Authors: Barbara Reggiani, Antonio Segatori, Lorenzo Donati, Luca Tomesani, Alberto Terenzi, Alberto Salice
• Keywords: AA7003, Extrusion, Hollow Profiles, Mechanical Property, Seam Welds

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