The brain is one of the most important organ in the human body. During sports, athletes lead a risk of suffering from blows to the head that cause injuries. To protect the athletes from head injuries, the helmet plays an important role. During this study, different parts of the liners have been examined to see if the liner is composed of one single material. Tests have also been done to analyze if the liners behave differently during different strain rates. To investigate the issues mentioned above, samples from four different liners were gathered. The samples were examined by doing compression tests and the results were used to calculate Young’s Modulus, Poisson’s ratio and stress-strain curves. This paper does not include testing of the outer shell of the helmet, but is solely about the liner.

The results of the tests show that the difference in the amount of absorbed energy, can vary depending on what material the liner is made of. Also, depending on the material, different liners behave differently when the strain rate is varied.