https://cronfa.swan.ac.uk/Record/cronfa24898/Download/0024898-19022016141050.pdf

The mechanics of composite corrugated structures: A review with applications in morphing aircraft

Experimental and numerical study on honeycomb sandwich panels under bending and in-panel compression

Nature has provided us with extraordinary resources to tackle design challenges facing in modern society nowadays. The multistate structures inspired by animal shell have proven effective to improve the impact resistance of composite laminate. This study aims to identify the crash responses and crashworthiness characteristics of bio-inspired sandwich structures composed of carbon fiber reinforced plastic (CFRP) panels and aluminum honeycomb. The crash responses, failure mode as well as the effects of core side length, height and impact velocity on peak load and energy absorption were explored herein. The differences of crashworthiness characteristics between the CFRP aluminum honeycomb sandwiches and bare CFRP panel were quantified. Two typical load-displacement relations, namely single-peak and double-hump curves, were observed in the tests. It was noted in the energy-displacement curve, where the slopes corresponding to the failure stages of the upper and lower face-sheets, were greater than that in the honeycomb failure stage, indicating that the bare aluminum honeycomb was of lower energy absorption capacity than the CFRP face-sheet. By comparison, the honeycomb filling was an effective way to improve the impact resistance of CFRP structure, yielding higher energy absorption and lower peak load during the impact. It was also found that the crashworthiness characteristics were more sensitive to the core length than to the core height; and the specific energy absorption (SEA) varied insignificantly with the increase in the core height. It was noted that the peak load, absorbed energy and SEA increased significantly under high impact velocity.

Dynamic crash responses of bio-inspired aluminum honeycomb sandwich structures with CFRP panels

An innovative sandwich structure with auxetic re-entrant cell honeycomb cores was proposed in this paper, and the dynamic responses and blast resistance of the honeycomb sandwich structures under blast loading were investigated numerically by employing the LS-DYNA. The honeycomb structures with thicker walls have a higher plateau force and specific energy absorption (SEA) under the compression loading. Deformation modes and deflections distribution along the axis direction caused by plastic stretching and bending were investigated in detail to have a better understanding of the deformation mechanism. Results show that the sandwich structures have a higher ability of resisting deformation along the longitudinal(Y)-direction than the transverse(X)-direction. In addition, the dynamic responses of honeycomb sandwich structures with different stand-off distances, graded cores and arranged orientations were studied. Results show that both the graded honeycomb cores and cross-arranged honeycomb cores can significantly improve the resistance ability of the sandwich structures under blast loading, compared with the ungraded honeycomb cores and regular-arranged cores. Comprehensively, the cross-arranged graded honeycomb cores with higher density of the upper layer performs the best under the blast loading compared with the other configurations, taking the effects of graded cores and arranged orientations into consideration. This work provides a reliable basis to design the sandwich structures with auxetic re-entrant cell honeycomb cores under compression and blast loading.

Dynamic response of sandwich structures with graded auxetic honeycomb cores under blast loading

Low-velocity impact response of composite sandwich structures: Modelling and experiment

Crashworthiness optimization of corrugated sandwich panels

Experimental and numerical studies on multi-layered corrugated sandwich panels under crushing loading

In this study, the energy absorption characteristic of two-layered corrugated core sandwich panels with different arrangements under quasi-static compression loading were firstly investigated experimentally. Then compared the experimental results of these two different arrangements two-layered sandwich panels, it was found that the symmetric-arranged corrugated sandwich panel has better energy absorption characteristic, which is more than 17.17% at 6 mm displacement before densification stage compare to regularly-arranged. Numerical calculations were carried out and good agreement is achieved between the experimentally results and numerical results. Finally, parameter analysis and optimization study of the symmetric-arranged two-layered corrugated sandwich panel under planar impact was carried out with crashworthiness criteria by using finite element model and response surface method. The selection of parameters in optimization study were determined by parameter analysis. The size of sandwich panel was firstly optimized for maximizing specific energy absorption (SEA). Then the multi-objective optimization of core cell shape with optimal sandwich panel size was optimized by maximizing SEA and minimizing the peak force, a Non-dominated Sorting Genetic Algorithms (NSGA-II) code was used to perform the optimization process in a gradual evolution trend, which led to obtain the Pareto front that consisted of a set of optimal objective function vectors.

Crashworthiness analysis of two-layered corrugated sandwich panels under crushing loading

The invention discloses an energy absorption structure for a corrugated sandwich panel. The energy absorption structure consists of an upper panel, multiple layers of corrugated cores, a sandwich panel and a lower panel, all of which are sequentially stacked and are adhered by an epoxy-structure adhesive or brazed to form an integrated structure; the section of the corrugated core is in a trapezoid, triangle or sine curve shape, and when the layer number of the corrugated cores is larger than or equal to two, the arrangement manner of the corrugated cores is regular arrangement, staggered arrangement or 0-degree or 90-degree arrangement. The energy absorption structure for the corrugated sandwich panel has the characteristics of light weight, strong toughness and good shock resistance; in the whole energy absorption procedure, the impact force is stable; due to the openness of a core material structure, the energy absorption structure can effectively and actively dissipate collision heat during collision, so that the structure material avoids yielding in advance under the influence of high temperature. The energy absorption structure for the corrugated sandwich panel can be applied to an automobile buffering energy absorption device, and also can be applied to any load and field needing the buffering energy absorption structure.

Shuyun Zhao

Papers

Crashworthiness optimization of corrugated sandwich panels

Experimental and numerical studies on multi-layered corrugated sandwich panels under crushing loading

Crashworthiness analysis of two-layered corrugated sandwich panels under crushing loading

Energy absorption structure for corrugated sandwich panel