Joint Focused Meeting IE0601-FP0802: Modeling mechanical behaviour of wooden cultural objects

JOINT FOCUSSED MEETING OF COST ACTIONS:

IE0601 “Wood Science for Cultural Heritage”

FP0802 “Experimental and Computational Micro-Characterisation

Techniques in Wood Mechanics”

Modeling mechanical behaviour of wooden cultural objects

Institute of Catalysis and Surface Chemistry Polish Academy of Sciences Krakow, Poland – April 12 – 13, 2010

Scientific outcome of the meeting

The meeting was divided into 3 sessions.

The first session was focused on modeling the time-dependant phenomena in wood. Authors of the presentations discussed influence of the dynamics of water sorption and time-dependant response of the wood on its deterioration. The bound water gain or loss is responsible for dimensional changes of the material, which leads to stress development in wooden objects. Therefore, the accurate modeling of bound water transport induced by the air parameter changes is the critical primary step in assessing environmental risks to wooden cultural objects. Developing models which can take into account the mechano-sorptive effects in the damage evolution have been a considerable problem in the damage mechanics. Such models were proposed by two authors who discussed critically their advantages and limitations in application to wooden art objects.

The second session concentrated on modeling mechanical properties of wood and wooden objects. A proper description of the mechanical properties of different wood species as a function of their age, water content and anatomical direction is necessary to predict response of the wood and wood containing objects. Mechanical characteristics and dimensional response of the wood to environmental conditions at the mesoscopic scale was critically discussed in connection with the transverse fracture of the material as well as construction of the historic wooden artefacts. Also the influence of different micromechanical parameters of waterlogged wood was discussed in the context of preservation of archeological artifacts. Finally, a concept of a multi-scale approach for the coupled modelling of mechanical and moisture behaviour of wood was presented and discussed.

The third session was focused on modeling of the environmentally-induced response of historic objects to evaluate risk and develop the best mitigation strategies. The authors presented different models capable of simulating response of objects of different level of complexity: panel paintings, historic pianofortes, or wooden ships. The most important problem discussed during this session was the interaction between different materials constituting historic artifact and consequences of the complex geometry of the object. The authors presented exemplary applications of the computer simulation which supported making practical decision about optimal climatic conditions in the vicinity of analyzed art objects.

Day 1, Monday 12 April

10:00 10:30 Roman Kozłowski / Karin Hofstetter Introduction of the two COST actions

Session I : Modeling of time-dependant phenomena in wood

Chairperson: Roman Kozlowski

10:30 11:00 Joseph Gril, Julien Colmars, Paola Mazzanti

Time-dependent mechanical behaviour of wood and implication for painted panels

11:00 11:30 Frederic F. Dubois

Differed damage modeling in wooden induced by environmental interactions

12:00 12,30 Callum Hill

Hydratation Kinetics experiments useful in predicting aging of wood

12:30 13:00 Wieslaw Olek

Accuracy of modeling of bound water diffusion in wood induced by variation of ambient air parameters