The takraw ball is a very unique interwoven ball used in the action game of sepak takraw. The traditional takraw ball is manufactured by conventionally weaving split rattan strips into a spherical basket. Modern takraw balls are manufactured by forming strips of plastics materials into interwoven hoop. These interwoven hoops form 12 pentagon holes and 30 intersections. The purpose of this study is to construct a finite-element (FE) model of a takraw ball in particular for normal impact simulation on flat surfaces under low speed conditions. Two FE models were developed to observe the dynamic behavior including impact forces, contact time, coefficient of restitution and deformation of the ball. The first model consists of a single solid hollow ball with 12 pentagon holes and the second model consists of six center strips and 12 side edge strips of
extrusion hoops to form 12 pentagon holes and 270 cross-sections. The models were also compared with results of experimental impact tests whereby the ball was impacted normal to a rigid plate at three different heights. The ball is described in the FE model as a linear elastic material.
It was found that the FE analysis solution of the ball model was found to be reasonably close with the experimental results. However further improvement need to be done by taking into consideration the nonlinearity of the takraw ball under large deformation as well as at high impact velocity.
Sepak takraw is a traditional sport in Asia in which the players use various
parts of their bodies to hit the ball, with the exception of their hands. Unlike
other sports such as soccer, boxing, and rugby, it is observed that none of
the studies in the literature have examined the injuries resulting from the
impact of the sepak takraw ball on the players’ heads during a game. This
study was initiated following the incidents of the 24th SEA Games in Korat,
Thailand, in year 2007, whereby a number of players from the Malaysian
Sepak Takraw Association (PSM) had to withdraw themselves from the
championship. These players suffered from headaches which were believed
to be caused by the impact of the sepak takraw ball, considering the fact that
heading is one of the basic movements used to hit the ball. Moreover, it is
expected that the sepak takraw ball travels at high velocities during the
game. Hence, the objective of this study is to investigate the impact of the
sepak takraw ball and its corresponding level of head injury among sepak
takraw players in Malaysia by means of numerical simulations and
experiments. In order to achieve this objective, a model of the scalp, skull,
cerebrospinal fluid and brain is first developed and simulations are then
carried out using finite element analysis (FEA) software. The results show
that the maximum speed of the sepak takraw ball before heading is 13.581 m/s while the maximum impact force on the head obtained from the simulations is 688.11 N. The maximum displacement and maximum linear acceleration of the brain’s centre of gravity is found to be 0.0080 m and 1674.5 m/s2, respectively, while the head impact power (HIP) is determined to be 11.366 kW. According to Newman, Shewchenko, and Welbourne(2000), the probability of concussion is 39% and based on the resultsobtained in this study, it can be concluded that the players may suffer from mild traumatic brain injuries (MTBI) due to the high impact of the sepak takraw ball during heading. Hence, it is recommended that the players wear protective headbands to reduce the impact during heading and prevent the occurrence of MTBI in the long term.