Design Of Impact Attenuator Research Articles

Design and experimental verification of composite impact attenuator for racing vehicles

Implementing measures to enhance collision energy absorption of a racing vehicle is essential to protect the vehicle and its driver and maximize the driving performance. In this study, based on the energy absorption characteristics of composites, the requirements of competition rules, and the overall vehicle arrangement, a preliminary design of an impact attenuator is performed. This paper will design the basic model with rules requirement in second section, and refer existing composite material-corrugated beam energy absolved structure, and write in half-corrugated beam energy absolved structure, so the model structure can be parameterize. Based on commercial nonlinear finite element analysis software LS-DYNA, established the numerical model. Subsequently, the optimization is divided into structural and lay-up optimizations. Using the LS-OPT software, and based on the response surface analysis method, the structure is optimized to obtain a composite impact attenuator model with the highest possible specific energy absorption. The lay-up of the model is optimized to attain a final lay-up with the minimum weight. Quasi-static axial compression and dynamic drop-weight impact tests are conducted to verify the optimization design. Finally, the composite impact attenuator of the racing car with high energy absorption efficiency, high specific energy absorption, and light weight is achieved.

Novel Design of Impact Attenuator for an 'Eco Challenge' Car

Thin-walled metallic tubular structures are generally used as impact energy absorber in automotive structures due to their ease of fabrication and installation, high energy absorption capacity and long stroke. However, unlike a normal passenger car where the impact energy can be distributed throughout the whole structure, the impact energy absorbing system of an Eco-Challenge car is confined within a limited space on the front bulkhead. The challenge is to develop an impact attenuator system that can effectively absorb the impact energy within the given space and fulfil the specified rate of deceleration. This new design utilized the standard Aluminium 6063 circular tubes, cut and welded into specific configurations i.e. stacked toroidal tubes with central axial tube sandwiched between two flat plates. Two configurations were investigated; circular and square toroids. Explicit non-linear FEA software was used to determine the impact response i.e. energy absorption, impact force and rate of deceleration. Both configurations showed promising results but the configuration that can be readily fabricated was chosen as the final design.

Lightweight design and crash analysis of composite frontal impact energy absorbing structures

Carbon fibre composites have shown to be able to perform extremely well in the case of a crash and are being used to manufacture dedicated energy-absorbing components, both in the motor sport world and in constructions of aerospace engineering. While in metallic structures the energy absorption is achieved by plastic deformation, in composite ones it relies on the material diffuse fracture. The design of composite parts should provide stable, regular and controlled dissipation of kinetic energy in order to keep the deceleration level as least as possible. That is possible only after detailed analytical, experimental and numerical analysis of the structural crashworthiness. This paper is presenting the steps to follow in order to design specific lightweight impact attenuators. Only after having characterised the composite material to use, it is possible to model and realise simple CFRP tubular structures through mathematical formulation and explicit FE code LS-DYNA. Also, experimental dynamic tests are performed by use of a drop weight test machine. Achieving a good agreement of the results in previously mentioned analyses, follows to the design of impact attenuator with a more complex geometry, as a composite nose cone of the Formula SAE racing car. In particular, the quasi-static test is performed and reported together with numerical simulation of dynamic stroke. In order to initialize the collapse in a stable way, the design of the composite impact attenuator has been completed with a trigger which is consisted of a very simple smoothing (progressive reduction) of the wall thickness. Initial requirements were set in accordance with the 2008 Formula SAE rules and they were satisfied with the final configuration both in experimental and numerical crash analysis.