The use of intelligent material systems in advanced automotive systems

Smart structure technology or adaptronics enables new and innovative approaches to optimise engineered structures with increased functionality in all fields of mechanical engineering. Basically, an increased functionality can be achieved by embedding sensors and actuators in loadcarrying structures combined with advanced control strategies. Over the last decades, these smart structures are mostly applied to noise and vibration control in high-cost light weight components where nowadays more and more light weight mass products such as automotives have to be considered. But particular light weight design in automotives is facing contradicting requirements such as safety, comfort and weight which cannot be overcome with conventional design rules. A reasonable balance between safety, weight and comfort has nowadays to be met by electronically means, active systems or new materials. But future even stricter legislations and higher demands for safety and comfort do need the introduction of smart structures and multifunctional material systems allowing. Particular noise, either from the vehicle radiated noise or vehicle interior noise will be one of the most challenging specifications for light weight vehicles only are met by active noise reduction concepts. As underlying principle for noise reduction concepts, Active Structural Acoustic Control (ASAC) is primarily being considered. Applying ASAC concepts, the noise radiation is controlled either by controlling the structural vibration of the radiating structure or by interrupting the structure borne sound path. Beside the challenges in designing a suitable control strategy, special focus has to be given to intelligent material systems as construction material or to high performing actuator systems which can be integrated in the vehicle body and capable of withstanding high and harsh operational loads. An example of the latter is the smart interface as a generic element which is currently being developed at the Fraunhofer Institute LBF. Various aspects of this smart interface as well as selected applications will be discussed. Further the application of intelligent material system for actively enhancing the crashworthiness will be addressed. The applications are taken from the European Integrated Project InMAR "Intelligent Materials for Active Noise Reduction" which deals with the development of active systems for mass production such as automotives, trains and infrastructure and the Integrated Project APROSYS "Advanced Protection Systems" dealing with crashworthiness of modern automotives.