AiF-Project Laser welded T-Joints


Development of basics and optimization of production an design of laser-welded T-joints – Development of connections of laser-welded pre-products for the application in ship- and steel bridge constructions

Field of Research: Fatigue Strength; Construction and development of laser welded profiles und steel-sandwich panels

Duration: 01st Jan. 2012 – 30th June 2015

Project Leader: Technical University Dortmund – chair of structural steelwork

Sponsorship: AiF IGF-No. 16935 BG / 1:

Transacted via:

  • FOSTA (Forschugnsvereinigung Stahlanwendung e.V.)
  • CMT (Center of Maritime Technologies e.V.)

Research partners:

Sponsoring companies:

Website: Laser welded T-Joints


The laser welding technique is getting common in more and more fields of joining technologies. Also in the shipbuilding branch the laser is well-established because of its positive attributes as the high welding speed and the low heat input by maintaining good welding qualities. Furthermore new assemblies and semi-finished products can be produced efficiently. For example it is possible to join closed structures such as steel-sandwich constructions in a cost-effective way by using laser-stake welding. In the conventional way three plates have to be joint with additional effort, see figure 1.

Figure 1: Cross-section of a steel-sandwich panel

Up to now experimentally approved design criteria for laser welded T-joints under loads, relevant in steel-superstructure, steel-bridge building and shipbuilding, are missing. Neither the above mentioned laser-stake welds are mentioned in the codes or classification rules nor examinations for the fatigue of laser welded T-joints under bending and shear loads and their combination, shown in figure 2, are existing.


Figure 2: T-joint under bending and shear loading

Thus the aim of this research project is the development and allocation of all needed scientific and technical knowledge for the application of laser and laser-hybrid welded T-joints in steel constructions. Furthermore basic connecting possibilities of laser welded sandwich plates for their application in large steel constructions should be investigated, as well as the specification of these connections for their field of application in the shipbuilding and steel-bridge building branches and their different requirements for load carrying constructions should be carried out. In this manner the cost-effectiveness and quality of such steel constructions will be improved significantly by the use of laser welded profiles and sandwich plates.


Peters, R.; Sumpf, A.; Ungermann, D.; Rüsse, C.; Fricke, W. und Robert, C.: Laserstrahlgeschweißte T-Stoß-Verbindungen in Stahlhohlplatten. Stahlbau 84 (2015), Heft 9, 643-649.

Fricke, W.; Robert, C.; Peters, R. and Sumpf, A.: Fatigue Strength of Laser-Stake Welded T-Joints Subjected to Combined Axial and Shear Loads. IIW-Doc. XIII-2597-15, International Institute of Welding 2015.

Robert, C.; Fricke, W.; Peters, R. and Sumpf, A.: Ermüdungsfestigkeit von laserstrahlgeschweißten T-Stoß-Verbindungen unter kombinierter Axial- und Schubbelastung. DVS-Bericht 315, 159-165, DVS-Media, Düsseldorf 2015.

Rüsse, C.; Fricke, W.; Peters, R.: Laserstrahlgeschweißte T-Stoß-Verbindungen (T-Stöße) – Entwicklung der Grundlagen und Optimierung der Herstellung und Bemessung lasrgeschweißter T-Stoß-Verbindungen – Entwicklung von Anschlüssen lasergeschweißter Halbzeuge für die Anwendung im Schiff- und Stahlbau, CMT-Forum Schiff & Hafen Heft Nr. 6, Juni 2012.


Prof. Dr.-Ing. Wolfgang Fricke

Dipl.-Ing. Christoph Robert