猪皮生物材料的力学特性研究

发布时间：2018-04-20 09:29

本文选题：皮肤 + 压缩松弛　；参考：《宁波大学》2014年硕士论文

【摘要】：交通事故中的汽车碰撞、体育运动中的相互踩踏以及军事行动中的爆炸冲击等都给人体带来了极大的伤害,更有可能导致生命危险。皮肤组织作为人体主要的组织器官,覆盖在人体表面,当人体受到外力伤害时,最先受到伤害的就是皮肤组织。对皮肤组织的系统研究,尤其是高速冲击下的动态力学研究,可为各类事故中对人体伤害的评估以及防护装置的设计提供一定的参考数据,也可为人体皮肤替代品的研发提供重要的理论依据。皮肤生物材料与传统的金属类工程材料相比,由于其具有一定的生命意义和较软的物理特性,使得皮肤组织力学性能的测试难度变得很大。本文以实验研究为主,针对以上的情况,制定了一套有效可行的试样制取方法及保存方法,保证试样为规则的圆柱状试样,尽可能的保持猪皮试样的活性。试样的制取方法和保存方法确定后,进行皮肤组织低应变率状态下的实验研究。低应变率状态下的实验研究有两部分,首先是皮肤组织的低应变率压缩实验,固定压缩应变值,分别得到不同加载速率下的应力-应变关系,对不同加载速率下的实验结果对比分析;然后是压缩松弛实验,研究了不同应变以及不同加载速率下的松弛情况。将低应变率压缩实验与压缩松弛实验的结果联系对比,分析探究它们之间存在的内在关系,对其存在的现象进行了初步解释。在已有的霍普金森压杆(SHPB)实验技术的基础上,探索研究了皮肤软组织在高应变率状态下的动态力学性能,得到不同应变率下的动态压缩实验数据,并与低应变率压缩实验数据进行对比,发现皮肤材料在很宽的应变率范围内具有极其明显的应变率效应。且对皮肤的应变率效应以及SHPB试验应力应变曲线上面的凸起现象做出可能的解释。在前人研究的基础之上,对皮肤软组织的本构模型稍做改进。已有大量文献中描述皮肤软组织的本构模型都采用描述橡胶材料的超弹性模型,或者是用来描述黏弹性材料的粘弹性模型。本文将超弹性模型与黏弹性模型结合起来,建立一个黏-超弹性模型,对实验数据进行拟合分析,最终得到皮肤材料的生物力学模型参数。在选择超弹性模型的时候,用各种超弹性模型对实验数据进行拟合,选择了拟合度较高的由Mooney模型改进而来的超弹性模型,确定了由改进的Mooney模型与Maxwell模型并联的方法,构建出皮肤生物材料的本构模型。
[Abstract]:The automobile collision in the traffic accident, the mutual stampede in the sports and the explosion shock in the military action have brought great harm to the human body, and may lead to the danger of life. Skin tissue, as the main organ of human body, covers the surface of human body. When the human body is injured by external force, the first injury is skin tissue. The systematic study of skin tissue, especially the dynamic mechanical research under high speed impact, can provide some reference data for the assessment of human body injury and the design of protective device in various accidents. It can also provide important theoretical basis for the research and development of human skin substitute. Compared with traditional metal engineering materials, skin biomaterials are more difficult to measure the mechanical properties of skin tissue because of their life significance and soft physical properties. According to the above situation, a set of effective and feasible methods for the preparation and preservation of the samples have been developed in this paper to ensure that the samples are regular cylindrical samples and keep the activity of the pig skin samples as much as possible. After the preparation and preservation of the sample were determined, the skin tissue was studied at low strain rate. There are two parts in the experimental study at low strain rate. Firstly, the compression experiment of skin tissue at low strain rate is carried out. The stress-strain relationship at different loading rates is obtained by fixing the compression strain value. The experimental results at different loading rates were compared and analyzed, and then the compression relaxation experiments were conducted to study the relaxation under different strain and loading rates. By comparing the results of low strain rate compression test and compression relaxation experiment, the inherent relationship between them is analyzed and the phenomenon of their existence is explained. The dynamic mechanical properties of skin and soft tissue under high strain rate were studied on the basis of the experimental technique of Hopkinson compression bar SHPB.The dynamic compression test data of skin and soft tissue at different strain rates were obtained. Compared with the experimental data of low strain rate compression, it is found that the skin material has an extremely obvious strain rate effect in a wide range of strain rates. A possible explanation is given for the strain rate effect of skin and the protruding phenomenon above the stress-strain curve of SHPB test. On the basis of previous studies, the constitutive model of skin and soft tissue is improved slightly. In many literatures, the constitutive models of skin and soft tissue have been used to describe rubber materials, or viscoelastic models to describe viscoelastic materials. In this paper, the hyperelastic model and the viscoelastic model are combined to establish a visco-hyperelastic model. The experimental data are fitted and analyzed, and the biomechanical model parameters of skin materials are obtained. When selecting the hyperelastic model, the experimental data are fitted with various hyperelastic models. The hyperelastic model, which is improved from the Mooney model, is selected, and the method of parallel connection between the improved Mooney model and the Maxwell model is determined. The constitutive model of skin biomaterials was constructed.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R318.08

【参考文献】