Modelling wooden cultural heritage. The need to consider each artefact as unique as illustrated by the Cannone violin

Abstract

This research work investigates the possibility to use a hygroscopic model based on Fick's law to predict the global moisture content variations an historical violin undergoes during a concert. To set up the model to work some input are required such as: the object geometries, the wood species used, the thicknesses, the moisture diffusion coefficients, the permeability of varnished surfaces, the anhydrous masses of the moisture exchanging parts, the sorption isotherms, information often far from being available or measurable. At a first extent, the model was run on the environmental conditions recorded during nine concerts played with the "Cannone" violin (1743) and the computed mass variations compared with the mass variations recorded during the same concerts. The model, set with simplifying conditions and with diffusion coefficients from literature, has shown a very little predictive capacity. On the other hand, the model was tuned on the experimental data using an inverse procedure for moisture diffusion coefficient identification. After the tuning the model has shown a very good predictive ability showing how Fick's low can be profitably used to assess the mass transfer in a complex heritage object such as a violin. This paper highlights the possibility to successfully use the Fick's law to model mass transfer in a violin but also makes evident how such models must be tuned with real measurements in order to be effective.

Hygromechanical behaviour of wooden panel paintings: classification of their deformation tendencies based on numerical modelling and experimental results

“…where D 0 is the value of isotropic moisture diffusion. This approach was already applied by [32,33] and particularly by [34]. Furthermore, it is theoretically supported by [35,36], because at room temperature, vapour movement makes only a small contribution to the total transfer movements.…”

The Contribution of IoT to the Implementation of Preventive Conservation According to European Standards: The Case Study of the “Cannone” Violin and Its Historical Copy

“…Previous studies on this masterpiece had the goal to model [20] the violin in order to identify its structural [21], hygroscopic [22] and rheological behaviors [23]. In order to develop a hygroscopic model of the violin during use, a series of environmental and mass measurements were recorded during concerts, evidencing that violin mass variation depends mainly on environmental conditions and that the role of the player is negligible [24].…”

The transfer of heritage modelling from research to practice

“…A range of model types were present, including computational fluid dynamic [4,[21][22][23][24], thermodynamic [25,26], biological [27] and fuzzy logic [28][29][30] models. The models described had been used to capture processes such as moisture regimes [31][32][33], pollutant deposition [4,34], wind-driven sediment abrasion [5,21,23] and salt weathering [35,36]. Our selection does not capture all process-based models that relate to heritage, but our dataset encompasses a range of model types, applications and approaches that give a reasonable understanding of the current state of modelling within heritage science.…”

“…Therefore, for models to be usefully applied to heritage, the modelled spatial and temporal scales need to be relevant to the impact of processes of change relevant to the heritage value and utility associated with sites and objects. These scales can be used imaginatively, as shown by Marcon et al [32] who used the timescale of a concert to model the moisture in a wooden violin.…”