Simulationen und Messungen von Glockentürmen – Widerspruch oder Ergänzung?

Simulations and measurements of bell towers – contradiction or complementation? For the evaluation of the structural stability and the serviceability of bell towers the relevant static and dynamic loads have to be considered. The quality of the modelling of the bell tower is thereby decisive for the reliability of the results. However, since the effective stiffness of the system is often known only imprecisely, material tests can supply additional and more precise information. Concerning the dynamic loads the actual vibration behaviour plays a major role. For existing towers the quality of the model can be significantly improved by taking into account the results of vibration measurements. In this paper the connection between the calculative verifications and the results from measurements is presented considering as example the bell tower of the church St. Pius X in Luxembourg. The emphasis is placed on the calibration of the finite‐element‐model to ensure the consistency with the reality. It becomes obvious that without this calibration the calculative investigation would clearly contradict the results of the measurements, but due to the calibration the calculations are complemented by the vibration measurements in an excellent way.     

ThermoShield – ein Beitrag zur Wärmedämmung?

ThermoShield – a contribution to thermal insulation? For some time now, so called thermal coatings are being introduced onto the market. Advertisement to these products announce that these coatings reduce heating energy requirement in buildings considerably. These coatings are facade paintings, e.g the product “ThermoShield”, to which microscopic small ceramic bubbles are added. In the product data to these coatings, a heating energy saving up to 30% are mentioned. The manufacturer impute these saving to different effects of the “ThermoShield” coating. To check the upper mentioned promising product properties, the thermal behaviour of test specimens coated with “ThermoShield – Exterieur” are being studied within the scope of a research work at the University of Hannover. The evaluation of the measurement results showed, that the specimens coated with “ThermoShield” did not have the thermal properties expected and that this coating do not show any of the promised thermal insulating properties.     

Auf dem Weg zu einer CO2‐freien Wärmeversorgung – Probleme mit den Wegweisern?

On the way to a CO₂‐free heat supply – Problems with the signposts? It is examined, how well the proposed Energy Saving Ordinance 2009, the Hamburg Climate Protection Ordinance and the Renewables Heat Laws of the Federation of Germany and of Baden‐Württemberg are suited to achieve the expected aims of climate protection. Economical employment of renewable heat is not sufficiently sure up to now. Compensation measures are economically still more attractive than solar duties. CO₂ emission limits would be better than limits on primary energy demand. A combination of the Energy Saving Ordinance (EnEV) and the new Renewables Heat Law (EEWärmeG) is proposed.     

Schubert und Reuleaux – ein verpasster Paradigmenwechsel? – zum 200. Geburtstag von Johann Andreas Schubert (1808–1870)

Schubert and Reuleaux – missed chance for a paradigm change? – On the 200th anniversary of the birth of Johann Andreas Schubert (1808–1870). The appeal of the life and work of Johann Andreas Schubert is to be found in its outstanding universality and the diversity of the methods. What is most impressive is the broadness of Schubert's work at the Royal Polytechnic School in Dresden, where he remained for many years; it extends from mathematics and applied mechanics to mechanical engineering, from building roads and canals to building railways and bridges. Influenced by his successful contribution to the Commission's designs for the great Vogtland railway viaducts, Schubert switched to teaching construction engineering around 1850, a subject to which he remained dedicated for the rest of his life. Less well known is the fact that Franz Reuleaux, without doubt the best‐known and most controversial mechanical engineering theorist in Germany at the close of the 19th century, applied for the post of professor of mechanical engineering left vacant by Schubert. Questions regarding the paradigm change in the engineering sciences plus the interaction between theory of structures and mechanics of machines are investigated here by means of the complex appointment process.