A numerical model was set up based on extended finite element method (XFEM) to investigate the mechanism of microcracks in silicon cells of photovoltaic (PV) modules with different adhesive films. The three-dimensional numerical model of photovoltaic modules was validated by existing experimental results. The influence of two different adhesive films
EVA and POE
on the microcrack propagation of photovoltaic modules under uniformly distributed external loads was studied with the validated numerical model. This study shows that: the photovoltaic module with POE material exhibits a more uniform stress distribution
less localized stress concentration and lower average stress in the silicon cells in comparison with EVA
which would reduce the probability of the appearance of initial cracks. The crack propagation process in the silicon cells located in the medium and high-stress zones is investigated by introducing an initial crack. For the silicon cells in the high-stress areas
the crack area in the silicon cell with POE material is approximately half of that with EVA material. The POE material delays the crack propagation significantly. The comparison results indicate that POE material exhibits better toughness and crack resistance
which is a more effective solution for suppressing the appearance of microcracks in photovoltaic modules.
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