The sensor array was then put under an expanded polypropylene or EPP (a commonly used multiple impact helmet foam) with three different foam's densities 54.8, 69.0, and 86.1 kg/m3. A 20kN loaded cell was at the base of the array to collect the impact recording. The setup tried to evaluate the contact force between the helmet foam and the head. The helmet foams were tested at 5 J with the cold (-25C) and the room (20C) temperature. The sensor array covered only 36% of the total tested area but still good enough to capture the load. Knowing the impact stress could not cause the bone fracture; it can induce local tissue distress or propagate stress wave pulses to the underlying cortex. The data revealed how much the stress was absorbed by the bone and neurovascular structure under an impact. The Ouckama et al. 2010's test faced a challenge with the sensor impact duration and loading rates. At the time, these sensors reading on flexible and curvature surface were
The sensor array was then put under an expanded polypropylene or EPP (a commonly used multiple impact helmet foam) with three different foam's densities 54.8, 69.0, and 86.1 kg/m3. A 20kN loaded cell was at the base of the array to collect the impact recording. The setup tried to evaluate the contact force between the helmet foam and the head. The helmet foams were tested at 5 J with the cold (-25C) and the room (20C) temperature. The sensor array covered only 36% of the total tested area but still good enough to capture the load. Knowing the impact stress could not cause the bone fracture; it can induce local tissue distress or propagate stress wave pulses to the underlying cortex. The data revealed how much the stress was absorbed by the bone and neurovascular structure under an impact. The Ouckama et al. 2010's test faced a challenge with the sensor impact duration and loading rates. At the time, these sensors reading on flexible and curvature surface were