Numerical simulation of pressure-driven adhesive penetration into realistic wood structures

The material point method (MPM) was used to numerically model pressure-driven flow of adhesive into hybrid poplar wood. The cellular structure of the hybrid poplar was discretized in an MPM model by converting X-ray computed tomography (XCT) voxels from 3D scans of actual wood–adhesive bond lines into material points in the model. In the MPM model, a slab of adhesive between two wood adherends was forced into the modeled wood structure. The wood material was modeled as a rigid material and the adhesive as a compressible, non-Newtonian fluid. MPM is well suited for these simulations because it can handle the large deformation of the adhesive fluid as well as adhesive–wood contact. The MPM fluid model with contact was verified by 2D simulations of a geometry with a known analytical solution using the same parameters and resolution as the full 3D simulations. Multiple 3D simulations were run, and the modeled adhesive penetration at the end of the simulations was compared to experimental penetration observations in the source XCT data. The simulation results correlated well with experimental results.