The objective of this study was to investigate the effect of UV irradiation on the fatigue life of a bulk semi-crystalline polymer. Low-density polyethylene samples exposed to different UV irradiation doses were fatigue tested. Fatigue indicator based on dissipated energy per cycle was found to present the best correlation with the experimental fatigue results. A master curve unifying the experimental fatigue results for as-received and UV-aged materials was obtained when subtracting the dissipated energy threshold from the total dissipated energy. Finally, the evolution of the damage with cyclic loading was analyzed and preliminary modeling was attempted.

中文翻译：

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紫外老化对低密度聚乙烯半结晶聚合物疲劳行为影响的实验研究和建模尝试

本研究的目的是研究紫外线照射对块状半结晶聚合物疲劳寿命的影响。对暴露于不同紫外线辐射剂量的低密度聚乙烯样品进行疲劳测试。发现基于每周期耗散能量的疲劳指标与实验疲劳结果具有最佳相关性。当从总耗散能量中减去耗散能量阈值时，获得了统一原样和紫外线老化材料的实验疲劳结果的主曲线。最后，分析了循环载荷下损伤的演变，并尝试了初步建模。