Moisture-driven failure mechanisms in historical paintings: A phase-field approach

Craquelure significantly impacts the aesthetic and structural integrity of historical paintings. This study proposes a modeling strategy to simulate failure mechanisms in historical paintings subjected to humidity fluctuations. A simplified two-dimensional framework is proposed, where moisture diffusion is modeled within the painting, represented as two elastic-brittle solids connected through a cohesive interface. Two phase field fracture approaches are utilized: one simulates crack initiation and propagation within the paint layer, while the other describes adhesion at the interface. The model incorporates the interactions among the critical layers-canvas, rabbit skin glue, and paint-accounting for humidity-dependent changes in material properties and moisture-induced expansion. Numerical simulations under various scenarios demonstrate that the model effectively reproduces the complex failure mechanisms characteristic of craquelure, providing insight into moisture-driven degradation processes. This model can help design preventive conservation strategies that support the long-term preservation of cultural heritage.