Development of design methodology for planar and shell structures made of cementitious composites.
Final Report Abstract
The major objective of the project was to provide a model-based framework for characterization, dimensioning, modelling and assessment of planar and shell structures made of strain-hardening cementitious composites (SHCC). The following four aspects of modeling and design and assessment methodology were addressed: (I) Novel test setup has been developed for the characterization of the both the tensile behavior and anchorage behavior. This test setup has been included in the RILEM recommendation and has been also applied for projects realized by TU Vienna and ETH Zurich. The test serves as the basis for developed dimensioning and assessment procedure. At the same time it provides the data for the model calibration both at the meso and macro scale. (II) The developed dimensioning approach reflects the combined normal and bending loading of a cross section. The n-m interaction diagram forms the basis for the numerical assessment of the ultimate limit state of TRC shell structures including the effect of oblique loading on the composite strength. The underlying n-m interaction diagram is based on the cross-sectional strength characteristic of the composite obtained by the developed test setup. The described design approach has been successfully applied and tested with respect to its practical feasibility for the real-size large-scale TRC structures. (III) For the characterization of multiple cracking and statistical representation of crack width during the tensile loading a general multi-scale modeling framework covering the crack tracing algorithm, crack bridge simulation and modeling of reinforcement and its bond interface was introduced. (IV) The nonlinear load-bearing behavior of TRC shell structures including stress redistribution has been investigated using the developed anisotropic damage model. The model was accompanied with a systematic calibration procedure reproducing the strain hardening response obtained in the tensile test. The numerical model is able to capture the development of oriented, finely distributed crack pattern in a phenomenological way. Verification and validation of the model was performed using bending tests, slab tests and large-scale vault shell. It demonstrated have demonstrated its capability to realistically predict the nonlinear structural response including stress redistribution owing to matrix cracking. The developed model is both accurate and efficient and contributes to a deeper insight into the structural behavior of TRC shells. The developed framework encompasses the steps of the experimental material characterization, simulation of material and structural behavior, and ultimate limit state assessment. It has decisively contributed to successful design and construction of the prototype shell structures realized at the campus of RWTH Aachen University.
Publications
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(2017) Structural behavior of a lightweight, textile-reinforced concrete barrel vault shell. Composite Structures 171 505–514
Sharei, E.; Scholzen, A.; Hegger, J.; Chudoba, R.
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Brittle matrix composites with heterogeneous reinforcement: Multi-scale model of a crack bridge with rigid matrix Composites science and technology 89, 98-109, 2013
Rypl R., Chudoba R., Scholzen A., Vořechovský M.
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Toughness of Brittle-matrix Composites with Heterogeneous Reinforcement Procedia Materials Science 3, 2168-2173, 2014
Rypl R., Vořechovský M., Chudoba R.
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Thin-walled shell structure made of Textile Reinforced Concrete; Part I: structural design and construction. Structural Concrete, 16:106-114, 2015
Scholzen A., Chudoba R., and Hegger J.
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Thin-walled shell structure made of Textile Reinforced Concrete; Part II: experimental characterization, ultimate limit state assessment and numerical simulation. Structural Concrete, 16:115-124, 2015
Scholzen A., Chudoba R., and Hegger J.
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A strain-hardening microplane damage model for thinwalled textile-reinforced concrete shells, calibration procedure, and experimental validation. Composite Structures, 152:913-928, 2016
Chudoba R., Sharei E., and Scholzen A.
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Leichte Dachschalen aus Carbonbeton (Lightweight precast shell elements made of textile reinforced concrete: production, experimental investigations and application potential). Beton- und Stahlbetonbau, 111(10):663-675, 2016
Scholzen A., Chudoba R., Hegger J., and Will N.