The Dependency of Hollow Ball Deformation on Material Properties

The work presented in this paper details the development of a finite element (FE) model
of a soccer ball, allowing for a greater understanding of the performance of soccer balls under
dynamic conditions that are representative of play. The model consists of composite shell elements that include a hyperelastic strain energy potential equation to define the latex bladder layer and a plane stress orthotropic elastic material model to define the anisotropic woven fabric outer panels. The model was validated through a series of experimental tests whereby the ball was impacted normal to a rigid plate at an inbound velocity of approximately 34 ms-1 (76 mph), with each impact recorded using high speed video (HSV) techniques. It was found that the combined effects of ball design and panel material anisotropy caused impact properties such as impact contact time, deformation, and the 2D shape taken up by the ball at maximum deformation, to vary with pre-impact ball orientation. The model showed good agreement with the experimental measurements and was able to represent the effects of anisotropy in ball design.