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Mark Nichols

Ford, Axalta + University of Michigan

Stone Chipping of Automotive Coating Systems: Experiments and Simulations


The damage induced in automotive paint systems due to the high-speed impact of a well-defined projectile was investigated both experimentally and via finite element analysis. Impact variables studied included: projectile velocity, impact angle, and projectile shape, while paint system variables included intercoat adhesion levels, bake conditions, basecoat color, and layer thickness. Coating constitutive properties were assessed via a combination of quasi-static and high strain rate measurements. Chip performance was quantified via volume loss measurements with a non-contacting profilometer. Finite element simulations on a subset of the experimental impact conditions were conducted to assess the ability of the simulations to quantitatively predict the effect of constitutive property changes (adhesive and cohesive strength and toughness) and impact conditions on the chipping behavior. The simulations were shown to correctly reproduce the chip shape and size under a number of chipping conditions, and provided insight into formulation pathways to potentially improve stone chip resistance.


Biography coming soon.