Project Details
Projekt
Optimization approaches for robust and durable reinforced concrete and fibre concrete structures under consideration of scale bridging polymorphic uncertainty modelling
Subject Area
Applied Mechanics, Statics and Dynamics
Term
from 2016 to 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 312921814
The overarching objective of this project is the development of computational reliability and optimization methods for the lifetime-oriented design of reinforced and steel fibre concrete structures, which allow to follow the influence of polymorphic uncertainties throughout the life of the structure. Interacting loading and environmentally induced deterioration processes and the propagation of uncertainties through multiple spatial and temporal scales are accounted for by scale bridging models in conjunction with physically sound models for reinforced and fibre reinforced concrete and multifield structural analysis. Consideration of polymorphic uncertain data (combinations of stochastic, interval and fuzzy numbers as well as generalized uncertainty models) and probabilistic load models on the structural level while employing computational models to represent structural degradation processes at lower scales leads to a highly increased complexity of the problem. To cope with this complexity and to reduce the modelling effort, computational strategies, characterized by combining high fidelity models at critical locations of the structure (hot spots) and low fidelity models at the structural level in conjunction with model reduction techniques able to account for time dependence and high dimensional input spaces must be developed.Taking into account the results achieved in the 1st funding phase, the following main scientific questions are addressed in the 2nd phase of the project:• How do uncertainties at the material scale (fibre distribution, crack roughness, steel-concrete bond properties) and human induced imprecisions (e.g. position of reinforcement) propagate through spatial and temporal scales and affect the structural reliability?• Can simulations of the casting process of FRC structures help reducing uncertainties in the design of FRC structures?• How does the concrete and reinforcement design (fibres vs. conventional reinforcement and hybrid designs) and the associated levels of uncertainty affect the durability and lifetime of a structure? • Is it possible to determine the concrete cover size for an optimized durability oriented design, considering uncertain interactions between reinforcement design, cracking, and the ingress of corrosive substances? • How does a (retrofitting) design of a prestressed concrete structure, using high performance FRC materials, affect the fatigue performance and, consequently, the expected lifetime of the structure?The computational methods considering polymorphic uncertainties in the design of RC and FRC structures will be tested by means of a reference bridge project, which is characterized by a combination of a UHPFRC and a RC bridge deck and prestressed girders, for which material data and data from moisture monitoring are available.
DFG Programme
Priority Programmes
