Analysis of honeycomb core properties under different parametric conditions for the head injury criteria compliance in aerospace applications

There has been enormous boom in the air travel in recent times. There is increasing demand for the technological advancement nowadays towards the safety of the onboard passengers. Certification of aircrafts requires engineers to demonstrate that a head contact with any aircraft interior complies with the Head injury criteria (HIC) threshold of 1000 units specified in 14CFR 23.562, 25.562, 27.562. Analyzing injuries to the head of the occupant when it comes to contact with any aircraft cabin interiors is of serious issue. HIC compliance is a major concern for all the segments of the aircraft industry due to high cost involved in the certification.; This research is an attempt to find a cost effective and yet valid approach to solve the HIC problem for the front row bulkhead seats in transport aircrafts. Previous experience, Quasi static testing, Finite element modeling and Madymo biodynamic simulations are utilized for the HIC compliant bulkheads. Madymo (Mathematical Dynamical Model) is a software package which can be used to simulate the dynamic behavior of Mechanical systems. It has a unique combination of fully integrated multibody and finite element techniques.; Quasi static testing on various cell size honeycomb core configurations was carried out. Finite element modeling of honeycomb core was done using Msc Patran software package. Comprehensive parametric study has been carried out on different boundary conditions in which the bulkhead may be fixed. Variable thicknesses of the bulkhead which can be used has been looked upon in this study. Different restraint systems and varied seat setback distances have been used for the parametric study. Nylon belt and the Polyester belt are the two different types of belts with different elongation characteristics which are used in this study. The validated madymo models are then used to conduct a parametric study on the effect of the stiffness and strength of the bulkhead on HIC attenuation below the injury levels.