自然环境老化ETFE薄膜单轴拉伸力学性能研究

Uniaxial tensile mechanical properties of weathering aging ETFE foils

ETFE薄膜在自然环境老化后的力学性能是ETFE结构长期使用性能评价的基础。选取在室外自然环境长期使用后的ETFE薄膜,开展了微观形貌表征和宏观力学性能试验,采用能量法确定了自然环境老化ETFE薄膜的屈服点及弹性模量,基于数理统计分析了材料力学参数标准值。研究结果表明,自然环境老化作用使ETFE薄膜材料表面微观形貌粗糙,截面褶皱纹理密集,晶粒尺寸增大了7.8%。老化ETFE薄膜破断强度下降显著,屈服应力及弹性模量降低较大,其标准值为11.73、703.2 MPa,降低了14.9%、13.5%。研究扩展了ETFE薄膜材料力学的研究范畴,可为准确评估ETFE结构长期使用性能提供重要的力学参数。

The mechanical properties of ETFE foils after aging in natural environment are the basis for long-term performance evaluation of ETFE structures.In this paper,the aging ETFE foils were selected to carry out the micro-morphology experiments and macro-mechanical tests.The standard values of mechanical parameters were analyzed based on statistical methods.The micro results show that the rough surface morphology and dense cross-section wrinkles existed and that the grain size increased by 7.8%.The breaking strength,yield stress and elastic modulus of aging ETFE foils decreased significantly.The standard values of the yield stress and elastic modulus were 11.73 MPa and 703.2 MPa,which reduced by 14.9%and 13.5%.In general,these results are critical for accurately evaluating long-term performance of ETFE structures.