Simulation Study on the Mechanical Properties of Fuzz Buttons

Fuzz buttons are formed by interweaving and compacting fine metallic wires, resulting in a highly porous architecture with complex internal contact interactions. Their compressive behavior is governed by the evolution of wire-wire contacts, frictional sliding, local bending, and plastic deformation, which cannot be adequately captured by conventional homogenized models. To address this limitation, a process-informed finite element modeling approach based on virtual fabrication is proposed. First, the spatial trajectories of 24 beryllium copper wires are generated using a parametric three-dimensional weaving algorithm and smoothed by cubic spline interpolation to obtain continuous wire centerlines. The resulting preform is then virtually compacted to reconstruct the densified wire network and its contact topology. The model employs a globally controlled solid-element mesh, a penalty-based general contact algorithm, a Coulomb friction model, and an explicit quasi-static solution scheme. The size-dependent plastic response of the fine wires is further incorporated through a Nix-Gao-based correction to the constitutive relation. The model is validated against quasi-static compression experiments at compressive strains of 15%, 20%, and 25%. The relative errors in the predicted peak forces are 2.12%, 5.65%, and 6.81%, respectively, while the corresponding coefficients of determination for the force-displacement curves are 0.984, 0.970, and 0.973. The model successfully reproduces the nonlinear loading-unloading response and hysteretic energy dissipation over the investigated strain range. The proposed approach provides a physically grounded numerical framework for predicting the compressive behavior of fuzz buttons and investigating the mesoscopic mechanics of complex interwoven wire networks.