Numerical tools, such as the finite-element method, are increasingly used to design and evaluate the photovoltaic (PV) modules, providing for the reduction of development time and improved performance and reliability. However, high-fidelity material models are necessary to accurately model the complex structural behavior of the involved packaging materials. A common simplification used in recent years is to model the polymer materials (i.e., encapsulant and backsheet) as linear elastic, which will lead to inaccurate results. Therefore, in this work, we present a thorough characterization of the time- and temperature-dependent mechanical response of predominant PV module encapsulant and backsheet materials. Based on this material characterization, we developed and experimentally validated generalized Maxwell models to describe each material's viscoelastic response. In addition, we included measurements of the coefficient of thermal expansion and presented all material models in such a fashion for direct input into commercial finite-element method modeling software.

中文翻译：

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用于直接有限元方法输入的光伏组件封装材料的粘弹性材料表征和建模

数值工具，例如有限元方法，越来越多地用于设计和评估光伏 (PV) 模块，从而缩短开发时间并提高性能和可靠性。然而，高保真材料模型对于准确模拟相关包装材料的复杂结构行为是必要的。近年来使用的一种常见简化方法是将聚合物材料（即密封剂和背板）建模为线弹性，这将导致结果不准确。因此，在这项工作中，我们全面表征了主要光伏组件密封剂和背板材料的时间和温度相关机械响应。基于这种材料特性，我们开发并通过实验验证了广义麦克斯韦模型来描述每种材料 s 粘弹性响应。此外，我们还包括热膨胀系数的测量，并以这种方式呈现所有材料模型，以便直接输入商业有限元方法建模软件。