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- Vorobyev, Alexey, 1985-, et al.
(författare)
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Evaluation of displacements by means of 3D laser scanning in a mechanically loaded replica of a hull section of the Vasa ship
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Tidskriftsartikel (refereegranskat)abstract
- For development of full-scale finite-element models of large objects in culturalheritage it can be useful to mechanically test replicas of key parts toidentify structural properties which would otherwise not be available. Thispaper presents full scale tests on a replica of a section of the hull of the17th century warship Vasa in three load configurations. We focus on determiningdisplacement of the loaded replica from 3D laser measurements.Two measures were found useful, namely (i) 3D displacements at well-definedintersections of the wooden replica, and (ii) normal displacements of largersurfaces. Wood surfaces were preferred to steel parts of the rig since the lattershowed more scatter in displacement values in their point clouds caused bytheir reflective properties. The measurements were verified with draw-wire sensors. Some of these sensors were attached to the steel rig supporting thereplica and, therefore, measured relative displacements. The scanning datawas also useful to quantify the absolute movement of the steel rig supportingthe replica, which improved the precision of the measurements of replicadeformation. Finally, it is discussed how the replica test results can be usedin a model of the complete museum ship.
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| 3. |
- Vorobyev, Alexey, 1985-, et al.
(författare)
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Relations of density, polyethylene glycol treatment and moisture content with stiffness properties of Vasa oak samples
- 2017
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Ingår i: Holtzforschung. - : Walter de Gruyter GmbH. ; 71:4, s. 327-335
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Tidskriftsartikel (refereegranskat)abstract
- Treatment with polyethylene glycol (PEG) is the preferred method for conservation of waterlogged archaeological wooden objects. However, PEG impregnation leads to softening and increased hygroscopicity of the material. The present study compiles experimental results concerning the full elastic properties of PEG impregnated archaeological wood from the Vasa ship in relation to its basic density, PEG content (PEGC) and moisture content (MC). The results show a correlation between a more porous microstructure and high PEGC, and consequently, higher MC. The PEG and moisture contribute to the mass of the wooden object as well as to softening of the material, which are undesired properties in a larger load-carrying wooden structure. A compromise between the improved dimensional stability and degradation of mechanical properties should therefore be considered in the conservation of wooden object treated with PEG.
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