Fuzzy Probabilistic Models for Structural Serviceability
fuzzy probabilistic models, probability, serviceability, cracks width, optimization
Structural serviceability is of uttermost importance for the overall performance of many common structures. As a rule, both the load effects (serviceability indicators due to loading) and admissible constraints (ensuring required structural performance) are random variables of considerable scatter and significant vagueness. Common experience indicates that a structure does not loose its ability to comply with specified performance requirements abruptly at a distinct point of the serviceability indicator, but gradually within a certain transition interval. Fuzzy-probabilistic methods are therefore employed to analyze the structural serviceability. As an example, serviceability limit states of water retaining structures with respect to cracking are investigated in detail. Fuzzy probabilistic models are proposed to derive theoretical models for the limiting crack width. It is shown that the fuzzy probabilistic distribution of serviceability requirements may be used similarly as classical distribution function to specify the characteristic value of limiting crack width, to analyze reliability of crack width and to optimize structural design to achieve the minimum total costs.