Identification of realistic fluctuation velocities of wind pressure on building surfaces and modeling of long-term histograms

• Applicant: Professor Dr.-Ing. Frank Kemper
• Subject Area: Structural Engineering, Building Informatics and Construction Operation ; Applied Mechanics, Statics and Dynamics
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 507221621

Bonded connections are used in many technical areas, such as vehicle and aircraft construction. Besides that, various types of adhesives are used in the construction industry for subordinate connections. However, the usage of bonded connection for structural components, which require technical proof of their load-bearing capacity based on probabilistic theory is missing. This application is restricted as there are open questions regarding long-term behavior. In fact, there are no scientifically based proof concepts available in this regard. In the case of glued connections - in contrast to conventional fasteners - time-dependent effects of the material behavior need to be considered. Such an application would be advantageous from an economic and building physics point of view, especially for facade construction. The structural safety verification required for this purpose requires knowledge of the corresponding time-dependent effects due to wind loading. While there is already extensive knowledge of the expected mean and extreme values of wind pressure and suction on the facade surfaces of various types of buildings – information on the frequency of the pressure amplitudes (amplitude collective) and the frequency of the pressure change rates (collective of fluctuation speeds) are missing. The present project proposal would like to close this gap and systematically evaluate the aerodynamic effects based on existing and new wind tunnel data and de-rive corresponding modeling proposals. To allow modeling that is as realistic as possible, it is aimed to preserve the dependency of pressure coefficients on their rates of change. For this reason, the test data used for some measuring points were classified in a double-sided way in preliminary investigations. It was clearly shown that the high coefficient amplitudes of the facade pressures tend to be associated with low rates of change. In addition, it was basically possible to confirm that it is possible to derive statistical models for the frequency of peak pressures and pressure change rates from test data. It has also been shown that the positioning on a building has a significant influence on the double-sided frequency classification so a systematic investigation (for different buildings, flow directions, and for different building shapes) is necessary. The proposal is dedicated to this research task.

• DFG Programme: Research Grants