Effects of nonlinear moisture coefficients of expansion on rectangular Craquelure of oil panel paintings

Abstract In the subject of cultural heritage, understanding how craquelure develops and how it affects historical objects—especially panel paintings—is of importance. Here a bilayer system of panel painting made of gesso and wood support is considered. Gesso is a primed surface to adhere to oil. Because it is composed of paint pigment, chalk, and binder it has complex mechanical and chemical properties. The fully nonlinear gesso moisture expansion model is both used in this research to find the optimal rectangular patterns based on constructal theory. The constructal theory is utilized, which is in charge of the crack development during the initial drying phases of the produced painting. The compromise of two mechanisms—diffusion of moisture content and advection drying by fluid flow through the cracks—detects the ideal scale of rectangular patterns because the constructal theory is based on increased access to the drying currents that flow through the crack pattern. The two-dimensional rectangular solid is dried by the normal air fluid flow at the boundaries while moisture diffusion happens inside the domain. The spacing between blocks of crack islands which has the smallest drying time is then determined using parametric research as an optimal configuration. The capability of the constructal theory is shown by comparing the numerical findings with prior research and experimental data that have already been obtained. The approach and findings are generalizable to different craquelure pattern kinds and structural conservators.