Project: Coupled Structural-Aerodynamic Analysis and Control of wind-induced loads on civil engineering structures

In order to design slender and flexible modern tall buildings, efficient structural systems of high-strength materials are used to reduce their weight. These structures exhibit lower damping values than conventional ones, which make them more susceptible to wind-induced excitations, the latter having the potential to reduce their structural safety and cause discomfort to the occupants, adversely affecting the habitability and serviceability of the buildings. As the wind pressures vary spatially over the surface of the structure, there is the potential for the development of regions of high localized pressures, which are of particular concern for the design of cladding systems. In addition, the three dimensional simultaneous loading due to the building interaction with the wind, results in three structural response components (wind-induced vibrations in the alongwind, acrosswind and torsional directions)._x000D_It is evident that wind-induced excitation has to be regarded as an important design criterion for the structural integration (especially in the case of high-rise constructions). However, simple static or quasi-static treatment of the worst case scenario to account for the wind-induced loading may lead to unacceptably conservative designs in case of very tall buildings. Therefore, the knowledge of the accurate dynamic response of the building to any wind load is needed. This requirement that can be fulfilled by wind tunnel experiments. In addition, the need to suppress wind-induced excitations and improve the performance of tall buildings has led many investigations related to the testing and development of control techniques, COly by experimental means. Such techniques either concern aerodynamic modifications of the building geometry related to flow control (to suppress vortex-shedding) or to structural control aiming to improve the structure response to the excitation. In both categories, passive, semi-active or active control techniques are met in the literature. In the light of the above and in accordance with the current market demands and deficiencies related to the design of high-rise buildings, the aims of the proposed SARA project are:_x000D_- To develop a numerical procedure in a unified software for the unsteady coupled aerodynamic-structural calculation of wind loads on civil engineering structures, based on existing Computational Fluid Dynamics (CFD) and Computational Structural Dynamics (CSD) solvers, appropriately modified and combined in an effective and efficient way. The existing CFD solver requires modifications to account for wind flows in the atmospheric boundary layer over the ground, while the CSD one is a well-known, fully commercial software with the capability to provide the dimensioning of the structure as a result to the end-user._x000D_- To apply, demonstrate and validate this software to a real test case, concerning the dynamic response of a tall building to wind loads (where parametric studies can also be exhibited)._x000D_- To use the aforementioned software in a wind-structure interaction case of practical interest with flow control. For example, the impact of possible aerodynamic modifications of the cross-sectional shape of a tall building (tapering) on its performance against wind-induced excitations (passive flow control) could be examined, confirming relevant experimental results from the literature and providing at the same time practical rules and guidelines._x000D_By reaching the above aims, the final goal of the SARA project will be to obtain a generic computational platform with the capability of numerically simulating, testing and assessing the effectiveness of any possible (passive or active) flow or structural control mechanism that could be incorporated in the building model for the suppression of wind-induced vibrations, either acting upon the flow part of the phenomenon (vortex-shedding) or on the structural one (building performance). The final product will actually stand for a “numerical wind tunnel” that will enhance the architectural design phase with an extra design criterion, namely that of the structure response to wind-induced excitation, essentially shifting the experimental phase towards the final stages of the whole design procedure, a fact that is already routinely used in the aeronautics industry in the last decades. From a practical point of view, interoperability with other software tools will be provided._x000D_The project Consortium consists of a Company with experience in CSD and CFD software development and applications, a Engineering Consulting Office with experience in civil engineering structures and calculations related to wind loads and a Technical University Scientific Institute with experience in engineering applications of informatics.

Acronym SARA (Reference Number: 4797)
Duration 01/01/2009 - 01/01/2012
Project Topic The SARA product will be software suitable for the numerical simulation of wind-induced aeroelasticity phenomena affecting the performance of tall buildings, in everyday design and for the design of any possible (passive/active) flow/structural control mechanism implemented in the aeroelastic model
Network Eurostars
Call Eurostars Cut-Off 2

Project partner

Number Name Role Country
4 SOFiSTiK Hellas S.A. Coordinator Greece
4 Wacker Bauwerksaerodynamik GmbH Partner Germany
4 Ingenieursozietät Peil, Ummenhofer und P Observer Germany
4 Institut für Bauinformatik, Technische Universitaet Dresden Partner Germany