柔性基底上含过渡层纳米薄膜在双向拉伸下断裂损伤的实验研究

发布时间：2018-06-07 12:02

本文选题：双向拉伸 + 薄膜　；参考：《实验力学》2017年06期

【摘要】：含过渡层的柔性基底薄膜的力学性能对现代电子元器件的广泛应用至关重要,对其力学性能的深入研究变得极为迫切。本文针对其在双向拉伸载荷下的断裂损伤进行了实验研究。对125μm聚酰亚胺上沉积的不同薄膜结构进行不同加载比下的双轴拉伸实验,通过光学显微镜观察裂纹演化过程与饱和裂纹形态。根据最小应变能密度因子理论对裂纹演化的开裂角度进行了理论分析,用有限元分析了加载比例和过渡层泊松比对结构各层双向应力比传递的影响,并在不同薄膜结构和加载比下,对裂纹演化应变进行了比较。研究结果表明,在双向拉伸载荷作用下,薄膜裂纹呈现出网状分布,裂纹演化角度与加载比、裂纹初始角度相关;一级裂纹萌生的临界应变随着加载比降低而降低,二级及以上裂纹萌生的临界应变与各级裂纹的饱和应变随加载比降低而升高;在等双轴拉伸下,不同薄膜结构的含过渡层柔性基底薄膜一级裂纹的临界应变基本一致,二级及以上裂纹的临界应变显现明显差异。
[Abstract]:The mechanical properties of flexible substrates with transition layer are very important for the wide application of modern electronic components. In this paper, the fracture damage under biaxial tensile load is studied experimentally. The biaxial tensile experiments of different film structures deposited on 125 渭 m polyimide were carried out under different loading ratios. The process of crack evolution and the morphology of saturated cracks were observed by optical microscope. According to the theory of minimum strain energy density factor, the crack angle of crack evolution is theoretically analyzed, and the effect of loading ratio and Poisson ratio of transition layer on the bidirectional stress ratio transfer of each layer of the structure is analyzed by finite element method. The strain of crack evolution was compared under different film structure and loading ratio. The results show that under the biaxial tensile load, the cracks of the film show a network distribution, the evolution angle of the crack is related to the loading ratio and the initial angle of the crack, and the critical strain of the initiation of the first order crack decreases with the decrease of the loading ratio. The critical strain of crack initiation and the saturated strain of each crack increase with the decrease of loading ratio, and the critical strain of the first order crack of flexible substrate film with transition layer is basically the same under equiaxial tension. The critical strain of secondary crack and above crack is obviously different.
【作者单位】：天津大学机械工程学院力学系;
【基金】：国家自然科学基金(11572218)资助
【分类号】：O484.2

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