Much of the work surrounding finite element simulation of bat–ball impacts has focused on techniques describing the ball. Determining the accuracy of these models has been hindered by challenges in experimentally characterizing the ball's response. In the following, dynamic mechanical analysis and an instrumented impact test were used to characterize the solid ball at deformation rates representative of play. The ball was described in the numerical model as a linear viscoelastic material. It was observed that a Prony series model based on small deformation dynamic mechanical analysis did not provide sufficient energy loss upon impact, while a simpler Power Law model, fitted to large deformation data, described the measured energy loss and impact force over a range of speeds. Results of a parametric study are presented as a guide towards tailoring the parameters of the Power Law model to match the measured energy loss and impact force. Discrepancies observed between the experiment and the numerical model suggest that the ball response should be characterized in environments closely resembling game conditions.

The following considers the lift and drag response of three commercially available golf balls. The balls were projected with spin through still air in a laboratory setting to investigate a reverse Magnus effect, where balls move in the opposite direction of the expected lift force. The drag and lift coefficients were found by measuring ball position and speed at three points along its trajectory. Three ball types, with different dimple patterns, exhibited reverse Magnus behavior between 5 × 10⁴ < Re < 7 × 10⁴ and 750 < ω < 2250 rpm. The golf ball with circular dimples had the least severe reverse Magnus effect, C_L = − 0.1, while the ball with hexagonal dimples had the greatest, C_L = − 0.15. The magnitude of the reverse Magnus effect was related to the drag crisis of each ball model. As the slope of the drag crisis became steeper, the magnitude of the reverse Magnus effect increased.

In this study, we consider the nonlinear viscoelastic–viscoplastic behavior of adhesive films in scarf joints. We develop a three-dimensional nonlinear model, which combines a nonlinear viscoelastic model with a viscoplastic model using the von Mises yield criterion and nonlinear kinematic hardening. We implement an iterative scheme for the viscoplastic solution and a numerical algorithm with stress correction for the combined viscoelastic–viscoplastic model into finite element analysis. The viscoelastic component of the model is calibrated using creep-recovery data from adhesive films in scarf joints. The viscoplastic parameters are calibrated from the residual strains of recovered creep tests with varying load durations. A two-dimensional form of the model shows good agreement with the three-dimensional model for the scarf joint considered in this work and is compared with experiment. The numerical results show favorable agreement with the experimental creep and recovery responses of two epoxy adhesive systems. We also discuss the contribution of nonlinear viscoelasticity and viscoplasticity to the stress/strain distribution along the adhesive center lines. Viscoplasticity tends to lower the stress concentration.