The findings are summarized in a user guideline. In the following different welding simulation models will be created, based on which the determination of the model parameters to be developed is carried out. The experimental determination of residual stress is realized using a combination of sectioning method and X-ray diffraction by the BAM Federal Institute for Materials Research and Testing. Influencing factors are the local heat effect, the inner and outer flexibility, the initial stress state of the plates to be welded as well as effects due to phase transformation. The development and verification of different approaches is based on a large experimental and numerical program to small and full-scale specimens from mild steel (S355J2+N) and HSLA steel (S690QL). A further distinction will be made between empirical, analytical and mechanical models. To ensure their practicability, relevant parameters are to be characterized and converted into simplified approaches. The scope of research is the development of validated models for determining the extent and distribution of residual stress. In terms of a more economic design practical as well as realistic models for the implementation of welding imperfections need to be provided. Especially for HSLA steels this leads to large deviations as has been shown in various studies. For the implementation of welding imperfections such as distortions or residual stress Eurocode 3 (EC3) provides only simplified models neglecting the influence of welding parameters, initial conditions and the material. In terms of optimization nowadays the design is often carried out using finite element software. The use of high-strength steels leads to light and economic structures with a reduction in material and especially weld fabrication costs. With the introduction of EN steels with yield strengths up to 700 MPa are standardized. In crane construction the use of quenched and tempered steel S690QL or S960QL can be considered as state of art for many years. Due to the advanced rolling and heat treatment technology such steels combine high s trength with a sufficient level of ductility and good weldability. Nowadays high-strength low alloyed (HSLA) fine-grained steels are being increasingly used in steel construction.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |