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Comparison of methodical approaches to describe and evaluate uncertainty in the load-bearing capacity of a truss structure

 
: Melzer, C.M.; Platz, R.; Melz, T.

:

Tsompanakis, Y.:
Fourth International Conference on Soft Computing Technology in Civil, Structural and Environmental Engineering 2015. Proceedings : Prague, Czech Republic, 1-4 September 2015
Stirlingshire: Civil-Comp Press, 2015 (Civil-Comp proceedings 109)
ISBN: 978-1-905088-64-5
ISSN: 1759-3433
Paper 26
International Conference on Soft Computing Technology in Civil, Structural and Environmental Engineering <4, 2015, Prague>
Englisch
Konferenzbeitrag
Fraunhofer LBF ()

Abstract
Load bearing mechanical structures like trusses face uncertainty in loading along with uncertainty in stress and strength due to uncertainty in their development, production and usage. According to the working hypothesis of the German Collaborative Research Centre SFB 805, uncertainty occurs in processes that are not, or only partial deterministic, and can only be controlled in processes. The authors classify and compare different methodical approaches to describe and to evaluate uncertainty in the development phase of three simple two-dimensional linear mathematical truss structure models in a consistent way. The truss structures are assumed to be mounted statically determined. They are each loaded by a vertical static force at a similar node. The criteria to compare the methodical approaches for uncertainty analysis are the limit load condition in one of the columns in the truss structure due to that load. For that, the authors distinguish between stochastic and non-s tochastic or, respectively, probabilistic and non-probabilistic evaluation methods, depending on the quality of information of the internal system properties such as geometry and material, and external properties such as magnitude and direction of loading. As a probabilistic approach, direct Monte-Carlo simulation with full sample sets of internal and external property values are conducted exemplarily. Furthermore, the relation between the number of columns in a truss structure and the number of samples through the criteria of convergence is presented. Examples of interval and fuzzy analysis will give information about non-probabilistic uncertainty. The effectiveness and confidence intervals of the different methods will be evaluated by means of the uncertain limit load condition in one column of the truss structure due to uncertainty in internal and external system properties.

: http://publica.fraunhofer.de/dokumente/N-417995.html