Perpustakaan Digital ITB

The increasing population of electric vehicles is also accompanied by a rise in the accident rate caused by components in electric vehicles, one of which is battery damage. To minimize battery damage, a crashworthy protection system is needed. This is achieved by using materials that can absorb a large amount of energy. One such material with these properties is auxetic material, which is a structure with a negative Poisson's ratio, lightweight, and capable of absorbing large amounts of energy. This study is conducted by combining various types of auxetic materials or its base structure which then be optimized to obtain maximum Specific Energy Absorption (SEA). This study is carried out by conducting simulation using LS-Dyna. In this study, there are five new designs evaluated to analyze which design have an auxetic behavior. There are the combinations of chiral and hierarchical honeycomb, anti-chiral and half of hierarchical honeycomb, anti-chiral and half of hierarchical honeycomb with direction changes, anti-chiral and half of hierarchical honeycomb with ligament shape changes, and the combination of octagon base structure with anti-tri-chiral unit cell that connected with quadratic and hexagon base structure as addition. The design with octagonal base structure combined with anti-tri-chiral unit cell that connected with quadratic and hexagon base structure giving auxetic behavior, where the deformation kinematics in the form of rotating nodes appear and the lateral deformation of the structure is inward and resulting in a negative Poisson's ratio. Therefore, the novel auxetic design has been discovered and optimized with DFSS. In this study, DFSS together with Taguchi’s method and ANOVA will be employed to optimize structural design by leveraging simulation data. The most contributing factor in the simulation is the octagon ligament length and material with contribution percentage are 37.93% and 37.63%, respectively. The optimum configuration obtained from the study is the configuration with nodes diameter of 6.25 mm, octagon ligament length of 10 mm, quadratic vertical ligament length of 12 mm, and Al-Si12 material with thickness of 3 mm. This optimized design’s S/N ratio gain is 13.75 dB and yields 382.63% higher SEA compared to the baseline model, also it can protect the battery from failure by avoiding excessive deformation and have been proven by conducting the battery protection system simulation that the battery deformation is less than 2.9 mm which is under the deformation limit of battery before failure.