Project Details
Projekt
Model reduction and substructure technique - application to modular shell structures made of ultra high performance concrete
Applicant
Professorin Dr.-Ing. Stefanie Reese
Subject Area
Applied Mechanics, Statics and Dynamics
Term
from 2014 to 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 257611820
Shell structures are especially suited for the construction of light-weight buildings, since they can be constructed to have relatively thin dimensions. Shells can be also found in nature, so that in the context of bionics the construction can be oriented to examples in nature. In reinforced concrete construction the use of reinforced shells has been common for a long time. The construction of monolithical shells, however, needs a very high effort for rigging and formwork. This is the reason why concepts have been developed where shells are made out of modules which are then put together on the construction site. This concept of modules also offers the possibility to work with fractal structures. This idea is picked up and developed further in this project. The main focus of the research work lies in the supply of suitable numerical methods for the design and efficient static and dynamic simulation of such shell structures. This means to employ already existing substructure and model reduction techniques. These have to be adapted to the new field of use and have to be connected with non-linear finite element technologies. The main and in this existing research field so far unused advantage of the new combination of methods lies in the possibility to take into consideration the non-linear performance of the single modules with only very few (in the area of 3 to 5 inner) degrees-of-freedom per module. Redundant calculations for different elements of the same shape can be avoided. On the one hand optimal configurations of modules for different load combinations can be determined quickly. On the other hand the distinctive non-linear behavior of the (ultra high performance) concrete, also after the opening of the joints between the modules, can be taken into account. Due to the expected residual load bearing capacity the structures have high ductility. The concept mentioned here provides the composition of curved shell structures made of plane polygonal modules. The connecting zones between the modules shall be at right angle to their plane. In order to achieve the necessary angles for curved shells in the connection between two modules, joining parts are being used. These are being formed as semi-manufactured parts for different angles and are cut in length respective to the edges of the modules. The connection of the modules is achieved by centered unbonded prestressing . This joining technology allows the dismantling without destruction of the shells and therefore a further use of the elements. For the latter reason this form of construction can be used especially for temporal buildings. The already used parts can be used to build new shells with an entirely different shape.
DFG Programme
Priority Programmes
