A multi-scale and uncertainty approach for the analysis of the aging of timber art objects adhesively bonded by animal glues.

Panel paintings and decorated furniture are among the most significant timber art objects. Timber is generally a durable material. However, it is extremely sensitive to climate variations, which may cause its accelerated aging and degradation. Animal glues, used to hold wooden boards together, also play a crucial role in the decay process. This is due either to aging of the glue itself or to the stress redistribution caused by the swelling/shrinkage of adjacent wooden parts. As a consequence, the climate-related degradation of wooden panels often is due to failure of the glue joints between wood boards. These phenomena have been largely observed within the Climate4Wood project, a large museum study held at the Rijksmuseum in Amsterdam; however, a deep comprehension of the responsible physical mechanisms is still lacking. To limit the degradation process, current practice is to maintain very restrictive climate conditions. However, this involves huge costs and unsustainable energy policies for the museums. This project proposes a novel combined experimental/numerical study aimed at the true mechanistic understanding of aging and degradation of panel paintings and decorated furniture, exploring the roles and interactions between wood and the animal glues. The experimental work will characterize the aging response of wood, animal glues, and especially the wood/glue-line interfaces. A numerical multi-scale model, incorporating the behaviour of the underlying wood micro-structure, will predict the artefacts response over time, as a function of the climate conditions. Data-science techniques will interpret the large amount of data generated by the numerical simulations. Input parameters and validation of the model will be directly linked to the experiments. This study will provide an estimate of the artefacts degradation as a function of time and climate conditions. This will assist conservators in minimizing aging and degradation of these artefacts, and in applying a more aware and sustainable climate control.

Panel paintings and decorated furniture are among the most significant timber art objects. Timber is generally a durable material. However, it is extremely sensitive to climate variations, which may cause its accelerated aging and degradation. Animal glues, used to hold wooden boards together, also play a crucial role in the decay process. This is due either to aging of the glue itself or to the stress redistribution caused by the swelling/shrinkage of adjacent wooden parts. As a consequence, the climate-related degradation of wooden panels often is due to failure of the glue joints between wood boards. These phenomena have been largely observed within the Climate4Wood project, a large museum study held at the Rijksmuseum in Amsterdam; however, a deep comprehension of the responsible physical mechanisms is still lacking. To limit the degradation process, current practice is to maintain very restrictive climate conditions. However, this involves huge costs and unsustainable energy policies for the museums. This project proposes a novel combined experimental/numerical study aimed at the true mechanistic understanding of aging and degradation of panel paintings and decorated furniture, exploring the roles and interactions between wood and the animal glues. The experimental work will characterize the aging response of wood, animal glues, and especially the wood/glue-line interfaces. A numerical multi-scale model, incorporating the behaviour of the underlying wood micro-structure, will predict the artefacts response over time, as a function of the climate conditions. Data-science techniques will interpret the large amount of data generated by the numerical simulations. Input parameters and validation of the model will be directly linked to the experiments. This study will provide an estimate of the artefacts degradation as a function of time and climate conditions. This will assist conservators in minimizing aging and degradation of these artefacts, and in applying a more aware and sustainable climate control.