Additive manufacturing in steel construction: reinforced thin sheet metal for use in façade construction

Grebner Philipp, M.Sc.

In some cities there are already free-form facades made of sheet steel. However, these can only be realized with large sheet thicknesses and complex substructures. This results in high material consumption, manufacturing effort and the associated high costs.

By using wire and arc additive manufacturing (WAAM), much thinner sheets can be reinforced with welded-on ribs. This could replace previous manufacturing methods.

welding parameters

The determination of suitable welding parameters has shown that with the use of modified short arc welding (CMT), the temperature effect on thin sheet metal can be reduced that rib welds on thin sheets up to a thickness of 0.75 mm are possible.

In order to be able to weld sheet thicknesses of 0.75 – 1.0 mm, extensive process parameter studies are required. The welding process, the robot speed and the shielding gas play a decisive role here. The back of the sheet must not suffer any burn-through in order not to destroy the thin sheet for use in façade construction.

Deformation meets shaping

There are two options for shaping a WAAM-stiffened thin sheet:

1. plastic preforming of the sheet and subsequent stiffening using WAAM

2. to control the rib welds in such a way that a free-formed sheet is created from an initially flat sheet.

The adjacent image shows investigations into 2.

load-bearing capacity

Tensile specimens were taken from the weld metal to determine the load-bearing capacity of thin sheets reinforced with WAAM. The results show considerable potential with regard to the load-bearing capacity of the stiffened sheets. Both the yield strength and tensile strength are significantly higher than the base material of the thin sheets. In addition, similar stiffnesses and ductile material behavior are achieved.

Publications

[1] https://onlinelibrary.wiley.com/doi/10.1002/cepa.2299

[2] https://dast.deutscherstahlbau.de/veroeffentlichungen/dast-kolloquium

[3] https://zenodo.org/records/11453894

Funding

Open research topics for Bachelor students

Open research topics for Master students