摘要
Thin-film structures are widely used in industry due to their advantages in lightweight,flexibility and deployability.This paper investigates the wrinkling deformation pattern of square film subjected to in-plane torsion through the post-buckling theory of shell,with the geometric nonlinear behavior derived by energy principle and analyzed with finite element method.An equal-sized experimental verification platform is designed and fabricated,and the wrinkling surface of polyimide film driven by rotary motor is reconstructed by 3D-digital image correlation measurement and verified with finite element simulation comparisons.Wrinkling region within the film expands continuously as the torsion proceeds,accompanied by multiple wrinkling configuration transitions throughout the complete evolutionary process.Due to the non-axial symmetry between structure and loading,significant discrepancies arise in amplitude,span and wavelength between different stripes,effects of thickness,torsion radius and pre-stretch on wrinkling pattern configuration are further discussed.This study can provide valuable references for understanding the wrinkling mechanism of hard film under complex torsion loading.
薄膜结构因其轻质、柔性和可部署性等优点而被广泛应用于工业领域.本文基于板壳的后屈曲理论研究了方形薄膜在面内扭转作用下的起皱变形模式,并通过能量原理推导和有限元方法分析了该几何非线性行为.我们设计和搭建了一个等尺寸的实验验证平台,采用三维数字图像相关技术测量和重建了由旋转电机驱动的聚酰亚胺薄膜的起皱表面,并与有限元模拟的结果进行对比验证.随着扭转的持续进行,薄膜内部的起皱区域不断扩大,并在完整的演化过程中伴随着多种起皱构型的转换.由于结构与载荷之间的非轴对称性,不同条纹之间的幅值、跨度和波长均存在显著差异,并进一步讨论了厚度、扭转半径和预拉伸等因素对起皱构型的影响.本研究可以为理解硬质薄膜在复杂扭转载荷作用下的起皱机理提供有价值的参考.
基金
supported by the National Natural Science Foundation of China(Grant No.12472347).
