Lightweight structures have been well adopted in engineering fields. However, their mechanical properties and service life are strongly and negatively affected by structural imperfections. Efforts to reduce this negative effect were mostly focusing on quality control, which has drawbacks such as high cost and low yield. The hypothesis of this thesis is that by improving the structure’s tolerance for imperfection by utilizing liquid fillers such as water and the liquid nanofoam (LN), the safety of the structure and cost efficiency of manufacturing can be improved significantly.In this research, three criteria have been analyzed to indicate the structure’s imperfection tolerance capability, i.e. yield strength, post-buckling strength and energy dissipation capacity. Different dimensions and shapes of defects have been created on stainless steel TWTs in a controlled manner. The mechanical properties of the liquid-filled tubes have been investigated under quasi-static compression tests and compared to those of tubes without fillers.Our experimental results have shown that, while the hollow tube’s performance was significantly reduced by the structural defects, the hybrid structures had higher tolerance to the defects and maintained the mechanical properties with the presence of the defects. In addition, the selected liquid fillers improved the volumetric energy absorption efficiency of the lightweight hybrid structure by 148% compared to hollow structure.
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