STRUCTURAL BEHAVIOUR OF VARIOUS CORRUGATED SANDWICH STRUCTURES SUBJECTED TO QUASI-STATIC AND DYNAMIC LOADING



Boonkong, T
(2017) STRUCTURAL BEHAVIOUR OF VARIOUS CORRUGATED SANDWICH STRUCTURES SUBJECTED TO QUASI-STATIC AND DYNAMIC LOADING. Doctor of Philosophy thesis, University of Liverpool.

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Abstract

New designs of sandwich structures for modern high performance shipcraft have been proposed to be used in the Royal Thai Navy ships. Here, novel hybrid sandwich structures based on corrugated reinforced foam cores have been developed by combining various corrugated cores and Fibre Metal Laminates (FMLs) based on aluminium alloy and fibre reinforced composites, to maximise the functionality of the structures. New manufacturing and fabrication techniques have been introduced to improve the integrity of the corrugated core and the skins by achieving a strong bond across the skin-core interface, as well as the fabrication efficiency. The aim of this research work is to investigate the mechanical properties and structural response of the various novel hybrid corrugated sandwich structures under three-point bending, quasi-static and dynamic compression, impact and blast loading. Firstly, tests are conducted to obtain mechanical properties of constituent materials. Then extensive experimental work is undertaken to determine the load-displacement relationships, the failure mechanisms and energy-absorbing characteristics of a large number of corrugated-cores with different cell wall thickness, core configurations and reinforcement, types of foam cores, foam core densities, unit cell sizes, core-layers, core materials and cores with vertical reinforcements. The results reveal relationships of the structural response and types of the failure mode occurred during the tests. The finite element models have then be developed to simulate the response of the corrugated structures tested, which are validated against the corresponding experimental results in terms of deformation and failure modes. The agreement between the numerical predictions and the experimental results is very good across the range of the structures and configurations investigated. Here, the fibre reinforced composites before the onset of damage is modelled as an orthotropic linear elastic material and the damage is modelled using Hashin’s criteria. The aluminium alloys are simulated as an isotropic elastic material before the yield point, followed by strain hardening. The ultimate failure is modelled using the shear failure and ductile failure available in the commercial code Abaqus. Parametric studies are also carried out using the validated numerical models to investigate the structural responses of the corrugated curvilinear aluminium structures subjected to various loading and geometric and material conditions. The dynamic characteristics of the composite sandwich structures through series of experimental tests and numerical predictions investigated in this project can be used in the design of lightweight composite structures for energy-absorbing applications in aerospace, marine and vehicle transportation industries.

Item Type: Thesis (Doctor of Philosophy)
Uncontrolled Keywords: Composite, Corrugated core sandwich structures, Curvilinear-core sandwich structures, Dynamic loading, Fibre Metal Laminates, Hybrid sandwich structures, Low velocity impact, Quasi static, Specific energy absorption, Triangular Corrugated core
Divisions: Faculty of Science and Engineering > School of Engineering
Depositing User: Symplectic Admin
Date Deposited: 08 Aug 2018 08:53
Last Modified: 16 Jan 2024 17:21
DOI: 10.17638/03014270
Supervisors:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3014270