Engineering Structures that Adapt to Changing Environmental Conditions

Weather conditions such as wind and snow loads can cause failure and collapse of supporting structures in roofs and similar constructions. Based on new hybrid intelligent construction elements (HICE), researchers at the University of Stuttgart have developed a shell structure which is able to adapt to changing environmental conditions. In a further step, the scientists will now use their knowledge to develop machines from these new structural elements which will also be able to react to their environments and adapt to given conditions. According to experts, this development may eventually lead to a significant acceleration of entire construction processes in mechanical, electrical and control engineering.

A research group of six engineers from different fields such as civil, aerospace, mechanical and process engineering is funded by the Deutsche Forschungsgemeinschaft (German Research Foundation) with a grant of 1.858 m € assigned for the first three years of a six-year project. The research group has started to operate in June.

The structural elements (e.g. shafts, levers, tractive or surface elements) are provided with integrated sensors, actuators and control elements. Light-weight and wear-resistant materials increase their functionality. Within the course of three years, the scientists from Stuttgart hope to assemble six newly-developed HICEs (membrane shells, adaptive cover elements, tile coating elements, inflexible force transmission elements, hybrid rope elements, bearing and lever elements) into a large-scale demonstrator shell structure measuring five square metres, which will combine all of the HICEs' functionalities. The adaptive shell structure will be translucent and much lighter than conventional supporting structures. If a change in environmental factors such as wind load, wind direction or snow load occurs, the structure shall be able to dissipate strain autonomously and adaptively via levers, ties and shell elements in order to prevent failure. The demonstrator will be exhibited by the University of Stuttgart.

Portability to all engineering disciplines

In a second phase of the project, the participating researchers will try to show by means of further constructions that HICEs can be applied in all engineering disciplines. By way of example, a hybrid engine bonnet shall be developed which may be combined with state-of-the-art "active" bonnets. This could improve pedestrian safety significantly by preventing severe injuries in case of a collision with this type of bonnet: Standard active bonnets are able to report the clash via additional sensors to an electronic control device which then prompts the rear part of the bonnet to be lifted upwards via a lever structure. This creates a protective distance between the accident victim and the hard engine parts beneath the bonnet. An intelligent hybrid engine bonnet would additionally create a specific deformation of the bonnet in reaction to the parameters of the actual collision. Based on new materials, the bonnet shall be able to soften or harden relevant areas of its structure autonomously in order to prevent injuries as far as possible.

In addition, demonstrators for the application of HICEs in shaft-to-collar connections and machine enclosures will be developed.

The participating institutions are the Institutes of Mechanical Handling and Logistics, of Construction Technology and Technical Design, of Textile and Process Engineering, of Aircraft Design, of Design and Construction and of Metal Forming Technology. "Within six years, the research group will have developed an entirely new class of hybrid intelligent construction elements together with its respective constructional and computational methods. We will have reached a new level of systems integration", says research group spokesman Prof. Karl-Heinz Wehking.