Sicherheit von Stahl-Glas Tragwerken

• Forschungsstelle: COST
• Projektnummer: C02.0036

Schlüsselwörter (Englisch)

Structural glass; design concept; fracture mechanics; probabilistic modelling; resistance

Forschungsprogramme (Englisch)

COST-Action C13 - Glass and Interactive Building

Kurzbeschreibung (Englisch)

See abstract

Partner und Internationale Organisationen (Englisch)

AT, BE, CZ, DK, FI, FR, DE, EL, IE, IT, LT, NL, NO, SI, ES, CH, UK

Abstract (Englisch)

For centuries, the use of glass in buildings was essentially restricted to functions such as windows and glazing. Glass building components were therefore basically required to resist out-of-plane wind loads only. Improvements in production and refining technologies like tempering and production of laminated glass made the use of glass for load-carrying structural elements possible. Architecture's unremitting pursuit of ever increasing transparency has caused a sustained strong demand for such elements ever since. Considerable research has been undertaken in recent years to improve our understanding of the load carrying behaviour of structural glass elements, the actions those elements are exposed to and the requirements in terms of safety and serviceability that they have to meet. While these research efforts provided much insight into the behaviour of structural glass components, their design for structural safety remains problematic. Glass failure is the consequence of the growth of microscopic surface flaws under static loads. The behaviour of glass elements does, therefore, strongly depend on their surface condition as well as on the environmental conditions and load history that they are exposed to. The common limit state verification by comparison of the maximum action effect with the maximum, time-independent resistance - as it is mostly used for other materials - is not readily applicable. Moreover, the extrapolation from laboratory conditions to in-service conditions is a major concern. There is a long tradition and therefore considerable knowledge and experience using rectangular glass plates to resist uniformly distributed out-of-plane loads. All widely used codes, draft codes and design concepts focus on this case. The various approaches yield fairly differing results and are often not directly comparable due to formal incompatibility. When it comes to more complex situations - like in-plane loading, concentrated loads, actions that cause not only time-variant stress lev-els but time-variant stress distributions, slender structural elements (stability problems) or connections - things become more difficult. The currently available design concepts do not cover these cases and can not easily be extended to do so. The present research project aims at providing a substantial contribution to the development of the scientific bases for the safe and economic design of glass structures. This will facilitate the application of such structures in practise, accelerate the design process and increase the structural safety. The basic question is: 'How can and should a structural glass element of general geometry be con-veniently and accurately analysed and designed for general conditions?' More specifically, the tasks are as follows: 1. Establish a consistent, general and flexible model for the mechanical behaviour of structural glass elements. The model should allow for the analysis of 'classic' hazard scenarios including loads and constraint stresses as well as hazard scenarios causing surface damage. A comprehensive and clear derivation should allow its users to fully understand not only the model itself but also its underlying assumptions and their consequences. The model's parameters should represent only one physical aspect each and be independent of test conditions. 2. Assess the reliability and sensitivity of the model and its overall suitability to represent actual in-service conditions. Improve existing testing methods in order to provide more relevant and accurate model input. 3. Implement the model in software to enable it to be used efficiently in research and practice. 4. Provide recommendations for the engineering design of structural glass elements.The research project is scheduled for completion by the end of 2006. The research work related to taks 1. and 2. is completed and mostly documented. Some extracts were published. Work on tasks 3. and 4. as well as its documentation is in progress.

Datenbankreferenzen (Englisch)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C02.0036