Dr.-Ing. Tassilo Rinder
Dr. Tassilo Rinder works at the Fraunhofer Society – Ernst-Mach-Institute, in the department of “Safety Technology and Protective Structures” in Efringen-Kirchen (Germany). EMI is specialized in physics of fast, transient processes to derive solutions for scientific and industrial applications. Crash, impact and shock-wave phenomena are investigated on a variety of materials and combinations in experiments as well as computational simulations. Dr. Rinder previously worked for many years at the University of Stuttgart (Germany) on the research of high performance concrete under sustained loading and presently is engaged with the evaluation of building structures and the development of innovative materials for the protection of structural parts against dynamic loading scenarios.
Development of a time-efficient collapse prognosis software for the protection of critical infrastructure buildings
The analysis of the status of a building structure in case of an extreme loading event is essential for the evaluation of dangerous areas. This information is not only important for the people inside the structure but also for first responders. Furthermore in the process of a growing application of building management systems it can support the dynamic calculation of escape routes. The German security research-project “AURIS – Autonomous Risk and Information System for structural analysis and monitoring of safety relevant buildings” aimed at the development and long-term proving of an innovative building security management system. Part of it was the development of a management system, which assesses the status of a building structure before, while or after a hazardous (extreme) event e.g. a terrorist attack with explosives, a natural disaster (earthquake, storm, or flood) or an accident (collision, fire, or explosion). In this scope the article describes the development, the required hardware and the application of this software tool, which is able to solve a time-efficient collapse prognosis. Such a tool can be used as part of the building monitoring system (BMS), which analyzes permanently the current state of the building. The status data required for the tool are captured through wireless and partly energy harvesting sensor nodes forming a wireless sensor network. These sensors measure at defined positions of the load bearing structure essential status-properties like the temperature or the strain. The latter provide the basis for the analysis tool. In the particular case of a severe damage, the software will be able to distinguish safe from unsafe areas in the building and thus giving the first responders the ability to rescue affected persons and to evacuate endangered areas. Various scenarios which can lead to progressive collapse were calculated with the analysis software, which bases on a special, simplifying rigid-body spring model developed by Fraunhofer EMI. With this, the computation time could be reduced to about 4% in comparison with conventional finite element methods. The paper will show the validation of the software for one extreme scenario on one exemplary simplified structure. A reinforced concrete column-beam structure was dynamically loaded through a contact detonation leading to failure of an essential structural member, which can result in progressive collapse of part or the whole building. The results of the analytical model and the experiment regarding loading capacity are compared and show good agreement.