Structural Optimization of a Surrogate Test Vehicle using Honeycomb Material Open Access
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Roadside hardware devices play an important role in vehicle safety, they redirect vehicles, reduce their speed and absorb impact energy. All roadside hardware devices have to undergo extensive testing procedures in order to validate and guarantee their performance. In order to reduce costs and to shorten the time needed for testing, the US Federal Highway Administration allows the use of reusable surrogate test vehicles. This thesis focuses on a surrogate vehicle equipped with a honeycomb nose where a combination of aluminum honeycomb materials is used to represent the crush characteristics of an actual vehicle front. In the past, the process of finding a valid material combination involved trial and error, experience and intuition, no purposeful methodology was employed. This thesis presents a way that allows to find a suitable set of parameters to represent any desired vehicle front with the surrogate nose construction. A nonlinear optimization problem that is solved with the response surface methodology in combination with finite element simulations is set up. Input are vehicle characteristics in the form of acceleration-time, force-time and force-displacement curves, output is a combination of honeycomb materials and geometric parameters. The methodology is tested with surrogates for two different vehicles, a 1979 Volkswagen Rabbit and a 2004 Kia Rio. In both cases, sets of parameters allowing the construction of a honeycomb nose representing the crush characteristics of the actual vehicle are found. Furthermore, the results show that the most important variable influencing the crush characteristics of the nose is the honeycomb material, geometric parameters are found to be of less importance.