P 213 - Ensuring the use of steel in offshore structures at greater depths by testing higher-strength pipe node hybrid constructions on a component-like scale

Hybrid pipe nodes on a component-like scale were tested in artificial seawater in a single-stage test and under seaway-typical loading. Despite the reduction in wall thickness, the use of these higher-strength materials resulted in an increase in the crack resistance in the critical areas of the cast steel insert by a factor of 2. Supplementary investigations on two conventionally welded pipe nodes without cast inserts showed that a TIG post-treatment and shot peening of the weld seams on these pipe nodes means additional safety against cracking at high cost. The results of the investigation provide an extended basis for the design of pipe joints. In addition, calculation models for application to different load constellations have been developed and are available. Offshore construction with steel using the hybrid pipe node concept and high-strength steel remains a durable, technically and economically viable alternative to concrete, even for greater sea depths. The advantages of this concept also apply to steel and mechanical engineering, e.g. in conveyor technology, in steel building and bridge construction and in vehicle technology.