Computational modelling of manually stitched soccer balls

Abstract

Soccer is the major ball sport, which attracts both viewers and participants worldwide. The primary equipment requirement is the ball, and the soccer ball market is as competitive as the game itself. The global interest of the sport provides an ideal international stage for the marketing of sports equipment such as soccer balls, boots, gloves, shin guards, and apparel. Multinational sports equipment manufacturers strive for superior product performance to enable commercial advantage, and the design and development of soccer balls is a crucial activity in achieving this. This work details the development of a finite-element (FE) model of a manually stitched textile-reinforced 32-panel ball used in an elite competition. A basic icosahedron FE model was produced to describe a thin-walled isotropic homogeneous shell, and this was subsequently enhanced to include a skeletal-like stiffer stitching region. Material testing was carried out to determine the mechanical properties of the bladder, outer panel, and stitching materials and prescribed within each model by a hyperelastic strain energy potential equation. A stiffness proportional damping coefficient was also used to describe kinetic energy loss characteristics. Each model was validated by an experimental impact testing under dynamic conditions that are representative of play, evaluation of coefficient of restitution, contact time, and deformation. It was found that the advanced soccer ball model accurately represented the deformation behaviour of the ball throughout impact.

Advanced finite-element modelling of a 32-panel soccer ball

“…An in-plane Poisson's ratio of 0.5 was used as it was hypothesized that this may assist in the buckling behaviour of fabrics throughout compressive loading, as opposed to the material undergoing in-plane compression. It was found in a previous study [23], that the stitching seam exhibited an elastic modulus of a factor of five greater than the outer panel material, a material property was assigned to the stitching region to reflect this. …”

Finite element modelling and experimental study of oblique soccer ball bounce

“…These diagrams have been extracted by Price, Jones, and Harland (2006a) from uniaxial tensile tests (The soccer ball in this experiment is very similar to the ball used in the reference). These properties are applied in the finite element model as hyperelastic materials with a Poisson's ratio of 0.490.…”

“…This simplification has no effect on the simulation of the impact parameters like coefficient of restitution and impact time. However, adding the stitched seam to the model will improve the accuracy of the deformation modeling by applying more realistic structural stiffness to the model (Price, Jones, & Harland, 2006a).…”

Validated dynamic analysis of real sports equipment using finite element; a case study using tennis rackets

“…Tennis equipment manufacturers must also have an in-depth understanding of how design changes will affect the performance of a particular racket. One way of doing this is through Finite element (FE) models which have been used by previous authors to further the understanding of sports equipment [7][8][9][10][11][12][13]. A previous FE model by Allen et al.…”