AirbagApplication for Structural Racing Car Component

In motorsports, there is a deep research in order to make cars more and more competitive, throughout an accurate study on aerodynamics, powerful and advanced engines, structural component design, materials and, of course, on racing strategy. That’s even more true when racing conditions are extremely severe, like in endurance races, such as 24 Hours of Le Mans, where changes in drivers and in racing conditions make the race more exciting. To improve performances, weight is one of the most strict design conditions: a lighter car is faster, more efficient and more competitive so that performances can be improved, with more controllability in acceleration and braking phases, reducing emissions and consumptions. Evolution in studies upon materials and structural applications has got a key role to reduce weight and the use of innovative structures is an open field for experimental tests. Many research works were performed upon materials used in motorsports, especially composite fiber reinforced ones. In [1], Adam presented a general overview on composite mechanical characteristics, production methods, and design principles for racing cars composite applications. In [2], a similar study was presented by Cole and Sherman referring to different light-metals and their use for automotive structural components. Innovative structural applications on car components were also studied in order to improve strength and reduce, at the same time, weight. In the fifties experimental tests carried out at Langley Aeronautical Laboratory of National Advisory Committee for Aeronautics (NACA) revealed that a small amount of pressure inside cylindrical components could increase strength. The first rigorous study upon this topic was performed by Lo, Crate and Schwartz [3]. From the comparison of experimental tests and analytical studies, they demonstrated that internal pressure can positively influence the resistance of cylindrical structures under torsional and compressive loads. Later some studies were carried out on specific cases, like silos and pipes, and Mathon and Limam [4] showed that the effects of internal pressure on closed cylinders under pure bending are dependent on the geometry and, particularly, on the ratio radius/thickness (R/t) and length/radius (L/R). Other studies [5] presented the effects on composite structures with different loads and with or without internal pressure. In this work, the effects of internal pressure on closed cylinders subjected to different loads were ® numerically investigated. Internal pressure was created throughout the use of LS-DYNA 971 airbag models and increasing levels of pressure were tested to evaluate the effect on the analyzed structure. Several FE models of different cylindrical geometries and loads were created and a comparison between metals and composite materials was numerically performed. A focused research on an innovative shape, that can take advantages from this kind of application, was also performed and its results compared with previous model ones.