@unpublished{dusane2023computationam,
  title = {Computational modeling of viscoelastic backsheet materials for photovoltaics},
  author = {Dusane, Ajinkya and Lenarda, Pietro and Paggi, Marco},
  journal = {arXiv preprint arXiv:2305.17810},
  year = {2023}
}

@article{dusane2023computational,
  title = {Computational modeling of viscoelastic backsheet materials for photovoltaics},
  journal = {Mechanics of Materials},
  volume = {186},
  pages = {104810},
  year = {2023},
  publisher = {Elsevier}
}

Backsheet is the outermost layer of the photovoltaic (PV) laminate which consists of polymers such as Polyethylene terephthalate (PET) or Polyvinyl fluoride (PVF). The viscoelastic response of these materials significantly affects the durability of the PV module. In this study, the viscoelastic response of commercially available backsheet materials is experimentally characterized and computationally modeled. An extensive viscoelastic experimental study on backsheet materials is carried out, considering the temperature-dependent properties to characterize the mechanical properties. Based on an experimental campaign, small-strain viscoelastic models based on the Prony-series (PS) and Fractional Calculus (FC) are herein proposed. The form of the constitutive equations for both models is outlined, and the finite element implementation is described in detail. Following the identification of the relevant material parameters, models are validated with experimental data, showing good predictability. A comparative study of model responses under different loading conditions is also reported to assess the advantages and disadvantages of both models. Such an extensive experimental study and constitutive modeling will help design and simulate a more comprehensive digital-twin model of PV modules, as illustrated by the benchmark problems.

@article{dusane2022simulation,
  title = {Simulation of bridging mechanisms in complex laminates using a hybrid PF-CZM method},
  author = {Dusane, AR and Budarapu, PR and Pradhan, AK and Natarajan, S and Reinoso, J and Paggi, M},
  journal = {Mechanics of Advanced Materials and Structures},
  volume = {29},
  number = {28},
  pages = {7743--7771},
  year = {2022},
  publisher = {Taylor \& Francis}
}

Delamination and cracking of matrix/fiber is a common failure phenomena reported in fiber reinforced composite materials. As complex stress states develop in laminated structures, they are prone to develop fracture phenomena. Therefore, designs with large damage tolerance are currently implemented in most of the industrial sectors. This can be achieved by designing such materials with superior fracture resistance, which requires a comprehensive understanding of failure mechanisms. Cohesive Zone Models (CZM) are a popular technique to study debonding and decohesion in composite structures. Furthermore, due to the accurate simulation of complex crack paths including crack branching, the Phase Field (PF) approach has gained notable relevance in fracture studies, including the interplay between debonding and crack propagation in the matrix. In order to get a further insight into these intricate scenarios, involving bridging mechanisms in intralayer and interlayer, crack simulation coupling the phase field approach and the cohesive zone model is herein exploited for identifying crack migration through material layers. The crack paths and the related force–displacement curves of 2D multilayered material models of complex laminates are predicted and compared.

@inproceedings{dusanecrack,
  title = {Crack growth studies in laminated composites using coupled cohesive zone and phase field approach},
  author = {Dusane, Ajinkya R and Budarapu, PR and Pradhan, AK}
}