Structural integrity assessment of glass components in Concentrated Solar Power (CSP) systems

• Published in: Theoretical and applied fracture mechanics 2015-12, Vol.80 (Part A), p.14-21
• Main Authors: Rosa, L. Guerra, Cruz Fernandes, J., Li, B.
• Format: Article
• Language: English
• Subjects: Assessments; Concentrated Solar Power (CSP); Design analysis; Design engineering; Fracture mechanics; Fracture strength; Glass; Glass components; Mathematical models; Probabilistic model; Reliability; Safety factors; Solar power generation; Weakest link theory
• ISSN: 0167-8442; 1872-7638
• DOI: 10.1016/j.tafmec.2015.09.002

•An integrated evaluation procedure for the design of glass components is developed.•Failure mechanisms due to over-loading fracture and static fatigue are considered.•The probability of failure is based on the weakest link theory.•Strength evaluation is implemented as the post-processing of finite element analysis.•Complexity of calculations is avoided considering selected highly stressed elements. Due to the importance of glass components in Concentrated Solar Power (CSP) systems, an integrated assessment procedure conceived to facilitate the design of an intrinsically brittle component, limiting the amount of calculations, is presented. Since the fracture strength of brittle materials depends on the size and distribution of flaws as well as the duration of loading, 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. In this paper, it is firstly reviewed and discussed the advanced methods to characterise the strength of glass. Then, based on the Weibull statistical method and the resulting probabilistic theory of the weakest link, a new modelling framework is proposed to consider different possible failure mechanisms (over-loading fracture and stress corrosion induced failure). In this way, the size effect as well as the multi-axial stress effect (including the contact stress between the glass component and the mount assembly) are considered. The integrated assessment procedure for structural glass elements is developed and implemented as a post-process of finite element analysis. The proposed procedure is demonstrated trough an application example: the design of a glass window to be used in a solar furnace reaction chamber.