TOWARDS DETERMINATION OF LOCAL AND OVERALL DISPLACEMENTS OF THE VASA SHIP STRUCTURE: EFFECT OF ITS MECHANICAL CONNECTIONS

摘要

The warship Vasa from the 17th century must be preserved for the future generations. There are many concerns currently being addressed by ongoing research efforts. The support structure is one of them, which needs to be redesigned. In order to do this, the local and overall deformation of the Ship’s structure must be identified. The earlier impregnation of PEG on the Vasa material is causing the material to creep significantly more than oak without PEG, resulting in an increasing deformation of the ship. In addition to this, the effect of the mechanical connections of the ship needs to be considered. Experimental tests were performed on a 1:1 scale replica of a representative section of the Vasa ship. Different load cases were applied in order to represent the current situation of the vessel’s connections. Linear displacement gauges as well as non-contacting image correlation systems were used as measurement methods to analyze the behaviour of the test sample. A validated computer model, using finite element method (FEM) simulations, with Vasa-material properties will be used to calculate the stiffness coefficients, which will be included in a simplified fullcomputer model of the entire vessel. Based on the latter, the overall and local displacements will be obtained. This is a necessary input in a full numerical model of the ship to optimize a new support structure.