Axial compression deformability and energy absorption of hierarchical thermoplastic composite honeycomb graded structures

Thermoplastic composites have advantages of high damage tolerance, reprocessing and recycling capacities which are in growing demand in lightweight engineering applications. Structural gradient were introduced to designed continuous woven glass fiber reinforced hierarchical thermoplastic composite honeycomb graded structures (HTCHGS) aim to improve on deformation stability and induce the failure processes. Axial compression tests were conducted to investigate compression behavior, energy absorption capacity and influence of structural gradient distributions. Experimental observation showed that failure of HTCHGS was induced and constrained as expected, stable rising load plateau achieved by presented staggered conical HTCHGS. The staggered conical HTCHGS obtained mean value of 0.64 and 1.56 J/g on crushing force efficiency and specific energy absorption at the densification displacement. FEM simulations were carried out among presented configurations by parameterized modeling, validated the induced deformation processes by structural gradient which matched well with the tests. Stress distributions were compared among six configurations at typical deformation stage, found core components of staggered configurations contribute more to energy absorption than that of regular configurations. Staggered dumbbell HTCHGS provide long and stable deformation plateau fill densification, and staggered conical HTCHGS are considered as optimal energy absorbing components among the configurations which give possible guidance for engineering structural designs.