Abstract
The degree to which a vehicle protects its occupants from the effect of accidents and lightweight requirements in the automotive industry has drawn the attention of composite materials, which have high specific stiffness, strength and energy absorbing capability. At present bumper design is made of single material which constrains it to the property of that particular material only. Additive manufacturing is a technique, which paves way for the manufacturing the combination of multiple materials. Among these combinations of materials, the main aim of the multi-material honeycomb structure is to resist the motion after impact and at the same time absorb energy progressively. The present study aims in providing new possibilities for combining multiple properties in a single product and investigating the effect of various design for additive manufacturing applications. From the results of dynamic FEA, a progressive failure is observed in the multi-material honeycomb structure with increased absorption of energy than single material. The force increases with increase in cell wall thickness due to the stiffness of the material and the force increases with decrease in cell wall size for both single and multi-material honeycomb structure. From the results of static FEA and static experimentation, a progressive failure is observed in multi-material honeycomb structure with increased absorption of energy than single material. The force increases with increase in cell wall thickness due to the stiffness of the material and the force increases with decrease in cell wall size for both single and multi-material honeycomb structure. From the static experimentation results of multi-material honeycomb structure the cell wall thickness of 1mm in multi-material the force experienced by cell size of 3.5mm is 82.3% lower than the cell size of 2.5mm. For cell wall thickness of 1mm in multi-material the force experienced by cell size of 3mm is 55.6% lower than the cell size of 2.5mm. For cell wall thickness of 1mm in multi-material the force experienced by cell size of 2.5mm is maximum. For cell wall thickness of 1.5 mm in multi-material the force experienced by cell size of 3.5mm is 77.8% lower than the cell size of 2.5mm. For cell wall thickness of 1.5 mm in multi-material the force experienced by cell size of 3mm is 28% lower than the cell size of 2.5mm. For cell wall thickness of 1.5 mm in multi-material the force experienced by cell size of 2.5mm is maximum. For cell wall thickness of 2 mm in multi-material the force experienced by cell size of 3.5mm is 77.6% lower than the cell size of 2.5mm. For cell wall thickness of 2 mm in multi-material the force experienced by cell size of 3mm is 28.6% lower than the cell size of 2.5mm. For cell wall thickness of 2 mm in multi-material the force experienced by cell size of 2.5mm is maximum.It is evident that the experimental results are in liaise with the theoretical equation where the thickness of the cell wall increases the force or stress induced increases and if the cell size increases the force or stress induced decreases.
| Date of Award | Feb 2020 |
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| Original language | English |
| Supervisor | Yuchun Xu (Supervisor) & Mark Prince (Supervisor) |