Evaluation of honeycombs with multidirectional load- carrying capacities in the crashworthiness design of helicopter cockpit model

Honeycomb is widely used in the collision field due to its excellent energy-absorption characteristics. However, for the traditional hexagon honeycomb, there is a huge gap between the in-plane and out-of-plane energy absorption capacity, which is not suitable for the scenarios with uncertain collision direction such as helicopter crashworthiness. In this study, an equivalent model for the bow-shaped honeycomb with multi-directional load-carrying and energy-absorption capabilities is established. The verification results show that the model has high accuracy. In addition, a cockpit finite element model is established and the honeycomb equivalent model was incorporated. Finally, a 15-degree drop simulation was carried out on the cockpit model, and the results are compared with those from the helicopter coupled with traditional hexagon honeycomb. It is found that the multi- directional load-carrying honeycomb has higher energy absorption capacity, which can provide better protection capability for pilots.