颗粒夹杂软基体复合材料的压痕力学性能测试与表征研究

发布时间：2018-04-15 12:23

本文选题：颗粒夹杂软基体复合材料 + 纳米压痕测试　；参考：《兰州大学》2015年硕士论文

【摘要】：纳米压入技术是一种测试各类材料微纳观力学性能的实验方法。该方法在传统的接触理论和宏观硬度的测试方法基础上,结合现代超精密器件的加工技术,通过记录压痕过程中载荷和深度的数据变化关系,进而得到样品的压入硬度、弹性模量、蠕变和松弛等力学特性参数。该方法具有操作便捷、材料要求简单等诸多优点,因此被广泛地应用在众多工程领域。近年来,虽然纳米压入技术在实验方法、实验原理、仪器分辨率等方面有了明显的提高和进步,但对于生物材料、高分子聚合物材料、复合材料等复杂材料的微尺度力学性能测试与应用还存在很多亟待解决的问题。本文首先采用纳米压入测试技术,开展了颗粒夹杂软基体复合材料的准静态和动态压痕力学性能研究。其次,通过有限元软件模拟材料的纳米压痕实验过程,分析了颗粒分布、压头几何尺寸、颗粒/基体模量对样品力学性能的影响。具体的研究工作有以下几个方面：1)以不同颗粒体积分数的颗粒夹杂软基体复合材料为实验对象,对其进行准静态纳米压痕测试,并得到材料的弹性模量和载荷-位移曲线等力学特性。改变测试的加载时间和保载时间,设置不同的实验方案,讨论了粘弹性(时间相关性)特性对样品准静态力学性能的影响。结果发现：当实验的压痕深度达到最大时,载荷-深度曲线出现负刚度现象。2)基于连续刚度测量法,开展了颗粒夹杂软基体复合材料的动态纳米压痕测试,得到了样品的复合模量,包括存储模量、损耗模量或者损耗因子。针对不同的颗粒体积分数、压入深度、测试频率、简谐振幅等测试条件,分析并获得了以上因素对样品动态力学性能的影响规律。3)基于ABAQUS有限元分析软件,建立了颗粒夹杂软基体复合材料的纳米压痕接触的计算模型并开展数值仿真。获得了几何尺寸(如颗粒分布和压头几何尺寸)、物理参数(如颗粒、弹性基体的模量)对复合材料压痕力学性能的影响与规律。
[Abstract]:Nanoindentation is an experimental method for testing the mechanical properties of various materials.This method is based on the traditional contact theory and macrohardness testing method, combined with the modern ultra-precision device processing technology, by recording the relationship between the load and the depth of the indentation process, the indentation hardness of the sample can be obtained by recording the relationship between the load and the depth of the indentation process.Mechanical properties such as modulus of elasticity, creep and relaxation.This method has many advantages, such as convenient operation, simple material requirement and so on, so it is widely used in many engineering fields.In recent years, although nanoindentation technology has made significant progress in experimental methods, experimental principles, instrument resolution, etc., but for biomaterials, polymer materials,There are still many problems to be solved in the measurement and application of micro-mechanical properties of complex materials such as composite materials.In this paper, the quasi-static and dynamic indentation mechanical properties of soft matrix composites with granular inclusions were studied by nano-indentation test technique.Secondly, the effects of particle distribution, die geometry and particle / matrix modulus on the mechanical properties of the samples were analyzed by simulating the experimental process of nano-indentation with finite element software.The specific research work includes the following aspects: (1) Quasi-static nano-indentation test was carried out on soft matrix composites with different particle volume fraction.The elastic modulus and load-displacement curve of the material are obtained.The influence of viscoelastic (time dependent) properties on the quasi-static mechanical properties of the samples was discussed by changing the loading time and holding time and setting different experimental schemes.The results show that when the indentation depth of the experiment reaches the maximum, the load-depth curve appears negative stiffness phenomenon. 2) based on the continuous stiffness measurement method, the dynamic nano-indentation test of the soft matrix composites with granular inclusions is carried out.The composite modulus of the sample, including storage modulus, loss modulus or loss factor, was obtained.According to different particle volume fraction, indentation depth, test frequency and simple resonance amplitude, the influence of the above factors on the dynamic mechanical properties of the sample is analyzed and obtained. 3) based on ABAQUS finite element analysis software,A numerical model of nano indentation contact of soft matrix composites with particle inclusions was established and numerical simulation was carried out.The effects of geometric dimensions (such as particle distribution and die size) and physical parameters (such as the modulus of particles and elastic matrix) on the indentation mechanical properties of composites were obtained.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

【共引文献】