A Method for the Assessment of the Dynamic Performance of Neck Protection Devices

In this paper a method for the evaluation of the dynamic performance of neck protection devices for motorcyclists is presented. The research project involves both experimental and numerical activities. An impulsive load is applied to the head of a 50th percentile male Hybrid III dummy while wearing a helmet by means of a pendulum of calibrated mass starting from a well-defined initial condition. The impact load and the load at the neck of the dummy are measured by means of two six axes load cells. Additionally, head linear and rotational accelerations are measured. The test procedure shows a very good repeatability and allows for the comparison of the force passing through the neck with and without neck protection devices. Since neck protection devices should work in situations in which no relevant head injuries are present, the experimental parameters (pendulum mass and speed) are chosen to cause a high probability of injuries to the neck together with a low probability of damages to the head while wearing a standard helmet. Injury indices, found in the literature, have been used to determine the neck injury level. A multibody model of the human neck, developed in Matlab™ SimMechanics™, is validated by using the data acquired during the tests. A study of real-world crashes has allowed the identification of reference impact scenarios which have been simulated by using the multibody model. The validated model is suitable to determine the chance that a motorcyclist would have significant neck injury with or without a neck protecting device.