Keywords: numerical monitoring, uncertain processes, textile reinforced concrete.

Concrete layers with textile reinforcement provide an opportunity for increasing the load-bearing capacity of existing reinforced concrete (RC) structures [1]. New textile technologies permit the effective production of textile fabrics with filament threads made of carbon or alkaline resistant glass in up to four directions connected by stitching yarns. These fabrics are inlayed in a fine-grained concrete matrix. Thus the new composite material textile reinforced concrete (TRC) results. Although the efficiency of this new type of structural strengthening has been proven by experiments, clarification is still required concerning the modified load-bearing behaviour and an assessment of the structural safety.

The date and the necessity of strengthening with TRC can be determined by monitoring. The in-situ monitoring is the state-of-the-art [2]. The in-situ monitoring allows the retroactive interpretation of the results caused by alteration processes that have already occurred.

The prognostic numerical structural monitoring is both an alternative and a supplement to the in-situ monitoring. As well as the retroactive interpretation of already occurred alterations, the future structural behaviour may be predicted. The prognostic numerical monitoring is based upon the numerical simulation of the load and modification process regarding different paths of structural behaviour.

A close to reality analysis of a structure during its lifetime requires the consideration of the complete load and modification processes simultaneously. Both processes run discontinuously. They cause time-dependent, discontinuous result processes.

The parameters of the load and modification process are usually uncertainty parameters [3]. Due to their predominantly informal and lexical uncertainty, they are described as fuzzy random processes, respectively fuzzy random functions.

Taking account of this uncertainty in the numerical simulation of the load and modification process requires a fuzzy stochastic structural analysis in the time domain. The fuzzy random processes are mapped on the fuzzy random result processes with the aid of a crisp or uncertain analysis algorithm.

The time dependent state of the structure during the load and modification process is evaluated by different newly defined uncertain time dependent indicators. These indicators enable the assessment of the benefit of the structural strengthening.

In the paper the physically nonlinear analysis of RC folded plate structures with textile strengthening is applied as deterministic fundamental solution [4]. The algorithms are demonstrated by way of an example.

1

D. Balageas, C.-P. Fritzen, A. Güemes (eds.), "Structural Health Monitoring", ISTE, London, 2006.

2

W. Brameshuber, "Textile Reinforced Concrete", State-of-the-Art Report of RILEM Technical Committee 201 - TRC, RILEM Publications S.A.R.L., Bagneux, 2006.

3

B. Möller, W. Graf, J.-U. Sickert, M. Beer, "Time-dependent reliability of textile strengthened RC structures under consideration of fuzzy randomness", Computers & Structures, 84(8-9), 585-603, 2006. doi:10.1016/j.compstruc.2005.10.006

4

B. Möller, W. Graf, A. Hoffmann, F. Steinigen, "Numerical simulation of RC structures with textile reinforcement", Computers & Structures, 83(19-20), 1659-1688, 2005. doi:10.1016/j.compstruc.2004.11.024

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