Parametric study and multi-objective crashworthiness optimisation of reinforced hexagonal honeycomb under dynamic loadings

Abstract

Hexagonal honeycombs have exhibited significant advantages in energy absorption and they are increasingly used as absorbers under crush conditions. Rather than restating details of the existing traditional regular hexagonal honeycomb, this paper introduces reinforced hexagonal honeycomb. The full-scale elaborator finite-element model created through LS-DYNA is validated by available theoretical solutions and experimental results. Afterwards, the validated simulation model is further applied to do a number of parametric studies on the reinforced hexagonal honeycomb under dynamic impact. The parameters such as stiffener thickness, expanding angle, cell length, cell wall thickness, impact mass, impact velocity and end constraint are employed to determine their relative effects on crushing behaviour of the reinforced hexagonal honeycomb. In the multi-objective crashworthiness optimisation, optimal Latin hypercube design method is used to select the sampling design points from the design space. To obtain a maximum specific energy absorption per mass ( ) capability and minimum initial peak stress ( ), response surface method, which is an accurate surrogate modelling method is adopted. The optimisation results show that the reinforced hexagonal honeycomb has a better energy absorption performance within the same limit of . This research is hence significant in providing technical support in potential applications of the reinforced hexagonal honeycomb used as crashworthiness structures.