An Investigation Of Energy Absorption Characteristics Of Honeycomb Structure Under Lateral Loading

• Main Author: Chuli, Abd Jumaidi
• Format: Thesis
• Language: English; English
• Published: 2019
• Subjects: TA Engineering (General). Civil engineering (General)
• Online Access: http://eprints.utem.edu.my/id/eprint/24661/1/An%20Investigation%20Of%20Energy%20Absorption%20Characteristics%20Of%20Honeycomb%20Structure%20Under%20Lateral%20Loading.pdf; http://eprints.utem.edu.my/id/eprint/24661/2/An%20Investigation%20Of%20Energy%20Absorption%20Characteristics%20Of%20Honeycomb%20Structure%20Under%20Lateral%20Loading.pdf; http://eprints.utem.edu.my/id/eprint/24661/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=116900

Nowadays, aluminium honeycomb has become well-known as a good energy absorbing cellular structure. Due to its lightweight and high stiffness properties, this structure has been more preferable metallic material compared to others in term of producing an energy absorbing structure. This study is concerned with the energy absorption characteristics of aluminium honeycomb structure. For the crashworthiness of a material research area, this study offers more understanding of the behaviour of aluminium honeycomb when subjected to quasi-static and dynamic lateral compression. Five different densities of honeycomb structure (empty and Oil Palm Trunk-filled with different densities) were introduced to study their deformation mode as well as the energy absorption characteristic. Since lateral compression is involved, all specimens were compressed in two directions; x1-direction and x2-direction. The results show that the honeycomb cores exhibit anisotropic response during the compression. Under quasi-static and dynamic loading, honeycomb compressed in the x1- direction has higher energy absorption characteristics values such as collapse load, mean load, plateau load and energy absorption value compared to the honeycomb cores that were compressed in the x2-direction. This is due to the cell wall arrangement of double thickness wall (2t) in the honeycomb core; the 2t cell wall aligned vertically when compressed in x1- direction, and horizontally when compressed in the x2-direction. The vertically arranged 2t cell wall caused the honeycomb structure to be stronger and has a higher stiffness value. In term of deforming modes, all honeycombs show a very different response from each other. Besides, the addition of filler element material (Oil Palm Trunk sawdust) into the honeycomb core caused the energy absorption values to increase by 83% in x1-direction and 91% in the x2-direction. Since the honeycomb is a man-made structure, the imperfections are randomly distributed in all parts of the structure. This caused the initiation point for the deforming mode of the honeycomb which occurred at the weakest point in the structure to be started in a random manner. All experimental results were compared by using finite element software, and a good agreement between them was shown for the compression of empty honeycomb. The main factors that caused the dissimilarity between the experimental and simulation results were found to be the imperfections of the honeycomb cores; the irregularities of the cell wall and the geometrical imperfections of the honeycomb that occurred during the manufacturing process.