Li Jun, Li Linan, Li Chuanwei, Wang Zhiyong, Wang Shibin, Xue Xiuli
Department of Mechanics, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Tianjin 300350, China.
Tianjin Key Laboratory of Modern Engineering Mechanics, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Tianjin 300350, China.
Materials (Basel). 2022 Oct 22;15(21):7421. doi: 10.3390/ma15217421.
With the development of flexible electronic technology, lately, there has been an increase in demand for flexible electronic devices based on soft polymer-substrate metal film structures in challenging applications. These soft polymer-substrate metal film structures must tolerate bending, folding, stretching, and even deformation into any shape without failing to be used successfully. As a result, research into the fracture behavior of soft polymer-substrate metal film structures is essential. The purpose of this study was to investigate how fractures develop in Cr film attached to a polyimide (PI) substrate under biaxial stress. A fracture development model was built to determine the fracture propagation law of soft polymer-substrate metal film structures under biaxial stress. Experiments and finite element methods were applied to verify the correctness of the model. The theoretical analysis and finite element simulation results showed that fractures appeared initially at the perimeter of the film and then propagated to the center under biaxial stress. The theoretical and experimental results indicated that the crack propagation direction was related to the ratio of biaxial loading, which became progressively parallel to the direction of small loading as the biaxial loading ratio increased. The theoretical results were in line with the experiment results, which could be used as a preliminary step for further research on the fracture behavior of film-substrate structures.
随着柔性电子技术的发展，近来，在具有挑战性的应用中，基于软聚合物基底金属膜结构的柔性电子器件的需求不断增加。这些软聚合物基底金属膜结构必须能够承受弯曲、折叠、拉伸，甚至变形为任何形状而不影响其成功使用。因此，对软聚合物基底金属膜结构的断裂行为进行研究至关重要。本研究的目的是研究在双轴应力下，附着在聚酰亚胺（PI）基底上的Cr膜中的裂纹是如何产生的。建立了一个断裂发展模型，以确定软聚合物基底金属膜结构在双轴应力下的裂纹扩展规律。通过实验和有限元方法验证了该模型的正确性。理论分析和有限元模拟结果表明，在双轴应力下，裂纹最初出现在膜的周边，然后向中心扩展。理论和实验结果表明，裂纹扩展方向与双轴载荷比有关，随着双轴载荷比的增加，裂纹扩展方向逐渐与小载荷方向平行。理论结果与实验结果一致，可为进一步研究膜 - 基底结构的断裂行为提供初步依据。
