Current Eurocode 3 regulations for the design of Combined Walls lead to uneconomical designs in case of shells where a substantial part of the shell yields before buckling. In such cases, strain based design will lead to more economical designs with adequate safety.
A European research project has been started, which aims to provide economic and safe guidance for tubes in Combined Walls. In this project, full scale four point bending tests on spirally welded tubes are performed. After providing background information, this paper discusses the test procedures and measurements before and during the tests. Extensive documentation of geometrical imperfections before the tests and their developments during the tests is presented. Comparisons are made with models and current design rules according to Eurocode 3.
In the buckling tests performed so far, the location of the local buckles was clearly influenced by the imperfection patterns. These imperfection patterns relate to the production method of the tested spirally welded tubes. Qualitative and quantitative analyses of the tests indicate that strain based design rules for this type of tubes in the considered D/t range are appropriate.
