Numerical Simulation of Thermal Shock for Glass-Glass BIPVs in Fire: Gaps and Challenges

Glass-glass photovoltaic (PV) technologies for building integrated (BIPV) applications are increasingly used in construction, due to several advantages. Besides, many complex aspects characterize the performance of these building components, and robust technical knowledge by many experts (with electrical, mechanical, structural, and architectural backgrounds) is usually required for their analysis. In ordinary BIPV applications, for example, thin glass covers are required to sustain thermal loads that derive from ordinary operational conditions, possible superimposed mechanical loads, even under accidents, such as fire. As such, among others, it is important to realistically predict the occurrence of first cracks in glass due to thermal shock, which is frequently followed by fallout. This chapter analyzes the potential of Finite Element (FE) numerical strategies for a more in-depth assessment of glass-glass BIPV performances in fire, to possibly support their optimal design and functionality assessment. Based on the literature background, a standard furnace test is numerically reproduced for a 1.046 m × 1.719 m glass-glass BIPV sample with 6 mm thick tempered covers and 1 mm thick Ethylene Vinyl Acetate (EVA) encapsulant. The attention is focused on the heat transfer transient analysis for first crack and failure time detection due to thermal shock of the exposed glass cover. The simulations give evidence of thermal shock after about 6′ of fire exposure, which fits well with the available experimental evidences. The critical discussion of comparative results, however, shows a major sensitivity to input material properties and poses the basis for further experimental and numerical investigations.