000013113 001__ 13113
000013113 005__ 20161114160328.0
000013113 04107 $$aeng
000013113 046__ $$k2009-06-22
000013113 100__ $$aVandenbergh, T.
000013113 24500 $$aVibration behaviour of trusses at conceptual design stage, under pedestrian loading and using morphological indicators

000013113 24630 $$n2.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000013113 260__ $$bNational Technical University of Athens, 2009
000013113 506__ $$arestricted
000013113 520__ $$2eng$$aWithin the framework of sustainable development we strive for constructions with a minimum volume of material. Only considering criteria on resistance and buckling, at the stage of conceptual design a clear hierarchy among the different structural topologies can be established with Morphological Indicators (MI). MI are dimensionless numbers that represent a property of a structure (e.g. volume). This allows one to compare the efficiency of structures objectively, with only a reduced number of variables to consider. Up to now, dynamic effects were not considered when designing constructions with MI. However, an optimum obtained by minimising the volume only considering strength, often results in solutions with problematic dynamic behaviour. To avoid these problems the stiffness, mass and/or damping characteristics must be modified, implying a volume increase, additional apparatus and as a consequence a cost rise. With an optimisation process that considers/predicts dynamic behaviour at the stage of conceptual design, an optimum can be obtained without the necessity to alter the (strength-optimised) construction drastically afterwards. This study presents a basic analysis methodology which allows predicting whether vibration norms/guidelines ask for a modification of the design or not, at conceptual design stage. The paper focuses on the prediction of the eigenfrequencies and peak accelerations of statically determined trusses under pedestrian excitation. Application of the Swedish norm Bro 2004 [1], the British standard BS5400 [2] and French guidelines by Sétra [3] on an existing pedestrian bridge illustrates that the different norms/design guidelines propose fundamentally different load models, yielding different acceleration levels. This lack of uniformity can yield contradictory decisions for the acceptance of the vibration level of a given design. A unified model is necessary, based on experimental validation. Moreover, the theory of MI -as presented in this paper- allows predicting the vibration behaviour of structural archetypes at conceptual design stage. Hence, it provides a user friendly tool during the first steps of the design process for the architect/structural designer.

000013113 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000013113 653__ $$aconceptual design, resonance, pedestrian loading, morphological indicators, trusses Abstract. Within the framework of sustainable development we strive for constructions with a minimum volume of material. Only considering criteria on resistance and buckling, at the stage of conceptual design a clear hierarchy among the different structural topologies can be established with Morphological Indicators (MI). MI are dimensionless numbers that represent a property of a structure (e.g. volume). This allows one to compare the efficiency of structures objectively, with only a reduced number of variables to consider. Up to now, dynamic effects were not considered when designing constructions with MI. However, an optimum obtained by minimising the volume only considering strength, often results in solutions with problematic dynamic behaviour. To avoid these problems the stiffness, mass and/or damping characteristics must be modified, implying a volume increase, additional apparatus and as a consequence a cost rise. With an optimisation process that considers/predicts dynamic behaviour at the stage of conceptual design, an optimum can be obtained without the necessity to alter the (strength-optimised) construction drastically afterwards. This study presents a basic analysis methodology which allows predicting whether vibration norms/guidelines ask for a modification of the design or not, at conceptual design stage. The paper focuses on the prediction of the eigenfrequencies and peak accelerations of statically determined trusses under pedestrian excitation. Application of the Swedish norm Bro 2004 [1], the British standard BS5400 [2] and French guidelines by Sétra [3] on an existing pedestrian bridge illustrates that the different norms/design guidelines propose fundamentally different load models, yielding different acceleration levels. This lack of uniformity can yield contradictory decisions for the acceptance of the vibration level of a given design. A unified model is necessary, based on experimental validation. Moreover, the theory of MI -as presented in this paper- allows predicting the vibration behaviour of structural archetypes at conceptual design stage. Hence, it provides a user friendly tool during the first steps of the design process for the architect/structural designer.

000013113 7112_ $$aCOMPDYN 2009 - 2nd International Thematic Conference$$cIsland of Rhodes (GR)$$d2009-06-22 / 2009-06-24$$gCOMPDYN2009
000013113 720__ $$aVandenbergh, T.$$iDe Wilde W., P.
000013113 8560_ $$ffischerc@itam.cas.cz
000013113 8564_ $$s3823167$$uhttps://invenio.itam.cas.cz/record/13113/files/CD151.pdf$$yOriginal version of the author's contribution as presented on CD, section: Algorithms and computational tools in structural dynamics (MS).
000013113 962__ $$r13074
000013113 980__ $$aPAPER