During collision, occupants and structures experience serious injuries and damages due to high impulsive force and poor impact energy absorption. Performance of energy absorption can be improved by selecting a suitable structure and material. A good crashworthiness structure should have low Initial Peak Force (IPF), high Crush Force Efficiency (CFE) and high Specific Energy Absorption (SEA). This paper introduces a new design that consists of stacked circular tubes within a square column which will be subjected to axial impact loading. The impact results were compared to static analysis of previous study in terms of IPF, CFE, SEA and DAF. Simulation results were validated by experiment before on embarking simulation parametric study. The experiment was conducted using the Drop Hammer Machine, Instron Dynatup 8250. Simulation results show good agreement with the experimental results. The increase in IPF and SEA were influenced by inertia compared to static at the same crush distance. Critical parameters were determined to give the best crushing performance among stacked tubes designs. From this study, it can be concluded that the best crushing performance depends on the dominant structure, amount of plastic hinge and structure stiffness.

Formula SAE is an international student design competition which is held in various parts of the world that challenges students to conceive, design, fabricate and test a single seater race car. Teams are evaluated based on business and technical presentations and dynamic performance of their cars. One of the important requirements of the Formula SAE car is its impact attenuator. It must be designed to absorb the specified impact energy. It is placed at the front of the car to protect the driver in the event of frontal collision. A new impact attenuator design which consists of aluminium circular tubes and L-sections arranged in a specified configuration is proposed. The attenuator is subjected to static and impact loads to determine its initial peak force (IPF), crush force efficiency (CFE) and specific energy absorption (SEA). Simulation result for static loading is validated by experiment. Minimum absorbed impact energy of 7350 J with peak acceleration of less than 40g and mean deceleration of 20g as specified in Formula SAE regulations is achieved. Impact simulation result also confirms that the impact attenuator is able to fulfil the requirements.