PROBABILISTIC DESIGN PROCEDURE FOR GLASS COMPONENTS IN CONCENTRATED SOLAR POWER SYSTEM

摘要

The fracture strength of glass components is dependent on the size and distribution of flaws as well as the duration of loading. Due to the inherent brittleness and strength scatter of glass materials, conventional design approaches are generally very conservative and large safety factors are often used. However, these large safety factors are somewhat arbitrary and not satisfactory, because it is not very clear what the true factor of safety really is. It is imperative to develop integrated strength evaluation methods for glass components, which are found more and more applications as functional and structural components. Based on the weakest link theory, this paper presents a new modeling framework to consider different possible failure mechanisms (over-loading fracture and stress corrosion induced failure), in order to take into account of the size effect as well as the multi-axial stress effect (including the contact stress between the glass component and the mount assembly). Then, an integrated assessment procedure for structural glass elements is developed, which is based on the probabilistic modeling of the complex behavior of glass fracture but avoids the complexity for calculation in applications. As an example, the design strength of a glass window suitable for a solar furnace reaction chamber is highlighted. The geometry and thickness of the glass window are optimized based on the stress analysis and the probabilistic strength evaluation.