Support Vasa
| Reference number | |
| Coordinator | Statens maritima museer - Vasamuseet |
| Funding from Vinnova | SEK 2 000 000 |
| Project duration | November 2012 - December 2016 |
| Status | Completed |
Purpose and goal
The goal was to develop a computer model, which can be used to assess and rank different support solutions, has been achieved. It is currently being tested in detail. The model is implemented in the software Ansys, which is widely used in industry. It can, however, be transferred to other finite element softwares if desired by the end users. The goal to be able to predict deformations and stresses is attained. A model for creep exists to predict future deformation.
Expected results and effects
Specimens of Vasa oak show that the material creeps (long-term deformation) more than expected, which can be explained by the presence of the preservation agent PEG having a softening effect on the wood material. The creep behaviour is part of the computer model and compared with measurements of the ship movement logged during the last 15 years. As expected, the computer model gives predictions of the how large the stresses become and how the ship deforms. These measures have reasonable values. A mimisation of the stress concentrations can be used to rank different support solutions.
Planned approach and implementation
Mechanical testing of Vasa oak has been performed under static and creep conditions. The constitutive properties have after homogenisation for structural variations and PEG contents been implemented in the finite element program. The geometry from laser scanning and optical measurements has been adjusted for stress and deformation calculations. For efficient calculations, suitable element types have chosen for the different parts of the ship, notably for the joints. Calculated values corroborate with expected and measured ones.