Enhancing Scratch Damage Resistance of PMMA via Layer Assembly with PVDF: Numerical Modeling Prediction and Experimental Verification

Abstract In this work, finite element modeling (FEM) and experimental test were combined to study the scratch damage behaviors of poly(methyl methacrylate) (PMMA) side of alternating multi-layered PMMA/polyvinylidene fluoride (PVDF) materials. Firstly, FEM was conducted to uncover the effect of layer thickness on critical normal load of material removal (Fcr) of the PMMA side, and the optimal thickness was determined. Then scratch tests were performed on PMMA side of the multi-layered materials, the layer thickness of which was controlled by changing layer numbers. It was found that 8-layer material possessed the highest Fcr on PMMA side (even 25% higher than pure PMMA), which was consistent with the FEM results. A more uniform deformation occurring at the surface layer was ascribed to decreasing the von Mises stress and ultimately preventing localized large deformation of PMMA, which therefore opened a new strategy to improve the scratch resistance of rigid polymers by introducing soft components.