轴向拉伸作用下超弹性管充气失稳的内压和形貌研究

超弹性管充气局部失稳现象与生物工程中动脉瘤形成机理相似。本文以两端密封的超弹性管为研究对象,从实验和理论两方面研究其在轴向拉伸作用下充气时的失稳现象。实验采用高频压力传感器测量充气过程中超弹性管内部压力的变化,高速摄像系统同步记录形貌变化的图像,分析超弹性管的几何尺寸和轴向拉力的改变对失稳临界压力的影响。基于连续介质力学理论,建立超弹性管充气时的控制方程并运用打靶法求解,理论分析轴向拉力与几何尺寸对超弹性管充气失稳的影响,并与实验结果比较;同时,预测超弹性管在任意时刻的形貌变化,分析特征点的变化趋势。

Internal Pressure and Morphology Analysis of Inflated Hyperelastic Tube Subjected to Axial Tension

The local instability phenomenon of gas filled hyperelastic tube is similar to the mechanism of aneurysm formation in biological engineering. In this paper, taking a hyperelastic tube with two sealed ends as study object, its local instability of inflation under axial tension condition was studied from both experimental and theoretical aspects.In experimental study, high frequency pressure transducers were used to measure the internal pressure variation of hyperelastic tube in inflation process; a high speed imaging system was used to synchronously record morphology change; based on above results, the influence of geometry size change of superelastic tube and the change of axial tension force on the critical pressure of local insterbility were analyzed. In theoretical analysis, the governing equation for inflated superelastic tube was established and solved by using shooting method, based on the theory of continuous medium mechanics. The theoretical results were compared with experimental data, both agree each other. Meanwhile, the morphology change of hyperelastic tube at any time was predicted, and the variation trend of characteristic points was analyzed.