In this work a methodology for impact identification on composite stiffened panels using piezoceramic sensors has been presented. A large number of impacts covering a wide range of energies (corresponding to small and large mass impacts) at various locations of a composite stiffened panel have been simulated using the finite element (FE) method. To predict the impact location, artificial neural networks have been established using the data generated from FE analyses. A number of sensor signal features have been examined as inputs to the neural network and the effect of noise on the predictions has been investigated. The results of the study show that the trained network is capable of locating impacts with different energies at different locations (e.g. in the bay, over/under the stringer and on the foot of the stringer) in a complicated structure such as a composite stiffened panel.

https://iopscience.iop.org/article/10.1088/0964-1726/21/10/105026/pdf

Determination of impact location on composite stiffened panels

http://coneheadhelmets.com.au/wp-content/uploads/2015/02/1-s2.0-S0001457513001036-main.pdf

Motorcycle helmets--a state of the art review.

Shock absorption performance of a motorbike helmet with honeycomb reinforced liner

http://spiral.imperial.ac.uk/bitstream/10044/1/14742/2/manuscript-oblique%20impact-02-forGreenOA.pdf

Effects of the presence of the body in helmet oblique impacts

The objective of this study was to develop and validate a set of Hybrid-III head and neck (HIII-HN) and impactor models that can be used to assess American football design modifications with established dummy-based injury metrics. The model was validated in two bare-head impact test configurations used by the National Football League and research groups to rank and assess helmet performance. The first configuration was a rigid pendulum impact to three locations on the HIII head (front, rear, side) at 3 m/s. The second configuration was a set of eight 5.5 m/s impacts to the HIII head at different locations using a linear impactor with a compliant end cap. The ISO/TS 18571 objective rating metric was used to quantify the correlation between the experimental and model head kinematics (linear and rotational velocity and acceleration) and neck kinetics (neck force and moment). The HIII-HN model demonstrated good correlation with overall mean ISO scores of 0.69–0.78 in the pendulum impacts and 0.65–0.81 in the linear impacts. These publically available models will serve as an in silico design platform that will be useful for investigating novel football helmet designs and studying human head impact biomechanics, in general.

Development of Open-Source Dummy and Impactor Models for the Assessment of American Football Helmet Finite Element Models

https://hal.archives-ouvertes.fr/hal-00574810/document

S Wilkes

Papers

FEA of oblique impact tests on a motorcycle helmet