P 354 - Mobile production of lightweight, simple steel tubes using hydroforming

This report deals with first respective relationships for curved modules based on special measurements. Multi-moment-receptions (MMA) on two shipyards showed the large share of welding work in the manufacturing process of curved assemblies, which is carried out mainly partly-mechanised. Additionally the MMA shows, that considerable additional work for fitting adjustment contains adequate rationalisation potential. The disposition of fabrication geometry data by CAD-systems has been analysed as well as suitable measuring techniques for the determination of as built data. As a result certain gaps and discrepancies related to the supply of manufacturing and measurement data by the CAD-system TRIBON were identified. Further investigations were carried out for the definition of references (nominal and as built levels for comparable positions) and for the determination of manufacturing and functional tolerances. Exemplary measurements of accuracy of pin device positions on a shipyard showed, that the accuracy of a number of used pin positions is not sufficient for accurate manufacturing. Within the scope of the project five curved assemblies were measured at two or three different manufacturing phases. The results lead to important understanding of the problems related to accurate manufacturing of curved modules. For the evaluation of welding shrinkages and the related variations in shape and dimensions practical manufacturing and functional definitions of reference points and representative geometry elements are necessary. For the determination of accuracy (i.e. the comparison of nominal and actual data) first concepts are proposed and trends regarding the data generation are indicated. The knowledge gained and the problems discovered along this research project lead to the need and the content of further research work necessary for accurate manufacturing of curved sections.