Scholarlink

<p>This study investigates the mechanical behavior of ethylene–vinyl acetate copolymer (EVA), a key encapsulant in photovoltaic modules, through uniaxial tensile tests over a wide temperature range (− 60 to 60&#xa0;°C) and strain-rate range (0.001–0.1&#xa0;s<sup>−1</sup>). Three distinct mechanical responses are systematically characterized: homogeneous deformation in the rubbery state, uniform yielding in the glassy state, and localized necking in the glassy state. A critical strain rate (~ 0.09&#xa0;s<sup>−1</sup>) is identified in the glassy state, demarcating the transition from homogeneous shear deformation dominated by α-relaxation to localized necking triggered by the activation of <i>β</i>-transition. Below this threshold, the material exhibits global yielding and strain softening; above it, <i>β</i>-relaxation leads to localized necking and inhomogeneous stress whitening. Based on these findings, a DSGZ constitutive model capable of unifying the above complex behaviors is established, with three sets of parameters calibrated for different mechanical states. For engineering applications, a corresponding Abaqus/VUMAT user material subroutine is developed, employing a radial return mapping algorithm for constitutive integration. Finite element simulations demonstrate that the subroutine not only accurately reproduces the macroscopic stress–strain responses but also successfully predicts the evolution of localized necking, showing excellent agreement with experimental curves. This work provides a high-fidelity simulation tool for the reliability design and assessment of photovoltaic modules under extreme environmental conditions.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Mechanical behavior, constitutive modeling, and finite element simulation of EVA encapsulants over wide temperature ranges

  • 期刊论文

  • 发表日期：

    2026年3月26日

查看全文
  • Keqian Zhu,
  • Haowen Wang,
  • Tao Sun,
  • Wenjing Chu,
  • Yanping Chen,
  • Yiyun Zhu

摘要

This study investigates the mechanical behavior of ethylene–vinyl acetate copolymer (EVA), a key encapsulant in photovoltaic modules, through uniaxial tensile tests over a wide temperature range (− 60 to 60 °C) and strain-rate range (0.001–0.1 s−1). Three distinct mechanical responses are systematically characterized: homogeneous deformation in the rubbery state, uniform yielding in the glassy state, and localized necking in the glassy state. A critical strain rate (~ 0.09 s−1) is identified in the glassy state, demarcating the transition from homogeneous shear deformation dominated by α-relaxation to localized necking triggered by the activation of β-transition. Below this threshold, the material exhibits global yielding and strain softening; above it, β-relaxation leads to localized necking and inhomogeneous stress whitening. Based on these findings, a DSGZ constitutive model capable of unifying the above complex behaviors is established, with three sets of parameters calibrated for different mechanical states. For engineering applications, a corresponding Abaqus/VUMAT user material subroutine is developed, employing a radial return mapping algorithm for constitutive integration. Finite element simulations demonstrate that the subroutine not only accurately reproduces the macroscopic stress–strain responses but also successfully predicts the evolution of localized necking, showing excellent agreement with experimental curves. This work provides a high-fidelity simulation tool for the reliability design and assessment of photovoltaic modules under extreme environmental conditions.