基于五元件模型的小肠动态粘弹特性研究

Research of intestines＇ dynamic viscoelasticity based on five-element model

进行了小肠动态粘弹特性的研究，应用五元件模型描述了小肠材料的松弛过程，得到了小肠材料的粘弹性本构方程。搭建了物理仿真平台，设计了负压吸附夹具，进行了小肠剪切松弛实验，实验验证了模型的有效性并进行了模型参数辨识。将该模型应用于振动式胶囊机器人，根据机器人的运动参数研究了小肠在一定频率下的动态粘弹性，得到了以下结论：五元件模型可以很好地拟合小肠材料松弛过程；小肠材料本构方程参数不是固定的而是随应变变化的；在胶囊自由振动过程中，整个系统呈现过阻尼状态，即非往复的衰减运动。

This paper presents the research on intestines＇ dynamic viscoelasticity （DV）. The relaxation process of an in- testine material was described using the five-element model （ FEM）, and the viscoelastic constitutive equation of the material was obtained. A physical simulation platform was constructed and a fixture was developed according to the negative pressure adsorption principle to perform the material＇ s shear-relaxation test. The FEM＇ s effectiveness was verified and the model＇ s parameters were obtained through the experiment. Then the model was applied to a vibratory capsule robot and the intestine＇ s DV at a certain frequency was obtained according to the motion parame- ters of the capsule robot. The paper comes to three conclusions. First, the FEM fits well into modeling the shear-re- laxation process. Second, the parameters of the intestine＇s viscoelastic constitutive equation are not constant, but changes with strain. Third, when the capsule robot makes a free vibration, the whole system is in an overdamping condition, which means that the capule robot moves damped with no reciprocation.