碳纳米聚氨酯泡沫吸能特性研究及其应用

发布时间：2018-06-19 23:00

本文选题：碳纳米管 + 聚氨酯泡沫　；参考：《吉林大学》2017年硕士论文

【摘要】：车身是汽车的重要组成部分,它是保护成员安全的一道屏障。提高汽车安全性的方法有很多种,包括:优化结构、改善工艺和采用新型材料。随着技术的不断发展,研究人员发现填充吸能材料是提高汽车安全性最有效、最直接的途径之一。但是,目前制造汽车所应用的材料已经渐渐不能满足汽车行业高速发展的需求,新型材料的研发迫在眉睫。碳纳米管作为一种具有超高强度、模量的纳米颗粒,非常适合作为填料来改善复合材料的性能。由于实验条件的不同,碳纳米管与复合材料相结合所形成的碳纳米管复合材料也会有很大差异,严格规范实验方法以及控制实验条件对于碳纳米管复合材料的制备起到至关重要的作用。聚氨酯泡沫材料能够成为汽车上应用最广泛的材料之一,主要是因为其制造成本低、制造方法简单以及本身具有一定的吸能特性。但是,由于其吸能效果相比于其他吸能材料(例如金属泡沫铝)偏低,渐渐地被研究人员忽视。纳米技术的出现促进了新型材料的开发,研究人员运用这些技术可以开发出具有高能量吸收特性的低密度轻质泡沫。本文将碳纳米管与聚氨酯泡沫的优势相结合,合理选用实验方法,制备出不同比例的碳纳米聚氨酯泡沫,对碳纳米聚氨酯泡沫以及其填充结构的吸能特性进行研究,并应用于B柱,以提高B柱的耐撞性。具体研究内容如下:(1)详细介绍碳纳米聚氨酯泡沫的制备过程。通过介绍实验条件以及原料,针对碳纳米聚氨酯泡沫的特性,选择合适的实验原料和制备方法。制备五种不同比例的碳纳米聚氨酯泡沫,作为本文的研究对象。(2)研究碳纳米聚氨酯复合材料的吸能特性。首先,运用准静态压缩试验方法,获取聚氨酯泡沫材料的载荷-位移曲线,并且采用相关吸能理论进行分析计算,选取吸能效果最佳的碳纳米聚氨酯泡沫。泡沫材料的压缩变形过程主要分为四个阶段:线性弹性变形阶段、弹塑性过渡阶段、屈服平台阶段和致密化阶段。然后,利用拉伸、弯曲试验所获取的材料参数作为数值模拟的数据基础,对碳纳米聚氨酯泡沫压缩过程进行仿真分析,验证仿真模型的有效性。(3)以不锈钢薄壁圆管为例,进行聚氨酯泡沫材料填充结构吸能特性分析。理论分析薄壁圆管的三种变形模式:轴对称模式变形、非轴对称模式变形和混合模式变形。然后利用准静态拉伸试验方法获得薄壁圆管的材料参数,制备三种不同的薄壁圆管压缩样件:空薄壁圆管、普通聚氨酯填充薄壁圆管和碳纳米聚氨酯填充薄壁圆管,分别进行准静态压缩试验,分析试验结果,对比能量吸收值与比吸能(SEA)值,验证碳纳米聚氨酯填充薄壁圆管的吸能特性。建立薄壁圆管有限元模型,对空薄壁圆管和碳纳米聚氨酯填充薄壁圆管分别进行数值模拟,验证仿真方法的正确性。(4)碳纳米聚氨酯泡沫填充B柱耐撞性分析。建立移动壁障与B柱有限元模型,将碳纳米聚氨酯泡沫填充于B柱结构,进行碰撞仿真。对比分析填充前后B柱的侵入量、侵入速度和吸能情况,验证碳纳米聚氨酯泡沫应用于车身部件的吸能特性。碳纳米聚氨酯泡沫填充车身部件可以提高车身的耐撞性,碳纳米聚氨酯泡沫具有比金属泡沫质量轻的特点,可以作为一种吸能材料。
[Abstract]:The body is an important part of the car, it is a barrier to protect the safety of the members. There are many ways to improve the safety of the car, including: optimizing the structure, improving the process and adopting new materials. With the continuous development of technology, the researchers found that filling energy absorption material is one of the most effective and direct ways to lift car safety. However, the materials used in automobile manufacturing have gradually been unable to meet the rapid development needs of the automobile industry. The research and development of new materials are imminent. As a kind of nano particles with super strength and modulus, carbon nanotubes are very suitable as filler to improve the properties of composites. The carbon nanotube composites formed by the combination of composite materials also vary greatly. It is very important for the preparation of the carbon nanotube composites to strictly regulate the experimental methods and control the experimental conditions. The polyurethane foam material can be one of the most widely used materials in the automobile, mainly because of its manufacturing cost. It is low, simple in manufacturing and has certain energy absorption characteristics. However, because its energy absorption effect is lower than other energy absorbing materials (such as metal foam aluminum), researchers have gradually ignored the development of new materials by the appearance of nanotechnology, which can be used to develop high energy absorption special. In this paper, the advantages of carbon nanotubes and polyurethane foam are combined, and the experimental method is used to prepare different proportions of carbon nanoscale polyurethane foam. The absorption properties of carbon nanoscale polyurethane foam and its filling structure are studied and applied to the B column to improve the crashworthiness of the B column. As follows: (1) the preparation process of carbon nanoscale polyurethane foam is introduced in detail. By introducing experimental conditions and raw materials, selecting suitable experimental materials and preparation methods for carbon nanoscale polyurethane foam, five kinds of carbon nanoscale polyurethane foam with different proportions are prepared as the research object of this paper. (2) research on carbon nanoscale polyurethane composites First, the load displacement curve of the polyurethane foam material is obtained by the quasi static compression test method, and the carbon nanoscale polyurethane foam with the best energy absorption effect is selected by the related energy absorption theory. The compression deformation process of the foam material is divided into four stages: linear elastic deformation stage, projectile The plastic transition stage, the yield platform stage and the densification stage. Then, using the material parameters obtained by the tensile and bending test as the data basis of the numerical simulation, the simulation analysis of the carbon nanoscale polyurethane foam compression process is carried out to verify the effectiveness of the simulation model. (3) a stainless steel thin-walled circular tube is used as an example to fill in the polyurethane foam material. Three types of deformation modes of thin-walled circular tubes are analyzed theoretically: axisymmetric pattern deformation, non axisymmetric pattern deformation and mixed mode deformation. Then, the material parameters of thin-walled circular tubes are obtained by quasi static tensile test, and three different compression samples of thin-walled circular tubes are prepared: empty thin-walled circular tubes and ordinary polyurethane filling. Thin-walled circular tubes and carbon nanoscale filled circular tubes were filled with thin-walled circular tubes. The test results were carried out respectively. The energy absorption properties of the thin-walled circular tubes filled with carbon nanofibers were verified by comparison of the energy absorption and specific energy absorption (SEA) values. The finite element model of thin-walled circular tubes was established, and the thin-walled circular tubes and carbon nanospu filled thin-walled circular tubes were filled. Do not carry out numerical simulation to verify the correctness of the simulation method. (4) the collision resistance analysis of carbon nanoscale polyurethane foam filled B column. A finite element model of moving wall barrier and B column is set up. The carbon nanoscale polyurethane foam is filled in the structure of B column, and the collision simulation is carried out. The intrusion rate, the intrusion velocity and the energy absorption of the B column before and after filling are compared and analyzed, and the carbon nanoscale is verified. Polyurethane foam is applied to the energy absorption characteristics of body parts. Carbon nanoscale polyurethane foam filling body components can improve the collision resistance of the body. Carbon nanoscale polyurethane foam has the characteristics of lighter than metal foam, and can be used as a kind of energy absorbing material.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ328.3;TB332

【参考文献】