粘弹性材料阻尼性能的研究-1.doc

摘 要 关键词：，， ABSTRACT Viscous and Elastic material(VEM),due to its excellent damping properties, is used broadly in recent years. It is a kind of material that both has flexibility and viscous properties . Viscous matrial have a loss of energy capacity in certain force circumstances,but it can not store energy; and the Elastic material can store energy not lose. Viscous and Elastic material is in between, when there are dynamic stress and strain, part of the energy is stored up as potential energy, while the other part of the energy is converted into heat energy being dissipated. This energy conversion and dissipation, performance as mechanical damping,has a good effect of vibration and noise reduction . It is widely used in shell structure of vibration and noise reduction. As the Elastic material to conduct applied tensile stress after unloading, the stress and strain inside the material is almost the same time increase or decrease between the two phase approach with phase, stress-strain curves become a straight line. For Viscous and Elastic material(VEM) , strain lags behind the stress, and this formats a stress-strain hysteresis loop,and the area enclosed by circles, performances as the dissipation of energy. In this experiment,we measuref the stress-strain hysteresis loop of several materials, and explain characteristics under tensile stress.And we also get measurement of infrared spectra, to compare the affect of different groups on the macro-mechanical properties of materials. KEY WORDS：VEM, damp, stress-strain hysteresis loop,infrared spectra 目 录摘 要 i ABSTRACT ii 目 录 iii 第一章 绪论 1 第二章 粘弹性材料（VEM）概述 3 2.1粘弹性的概念 3 1.理想粘性体的概念 5 2.理想弹性体的概念 5 2.2粘弹性材料的力学性质 6 1.蠕变 6 2应力松弛 8 3载荷速率效应 8 2.3粘弹性材料的动态粘弹性 9 1滞后现象 9 2力学内耗 10 2.4粘弹性的数学描述 14 2.5粘弹性的分子模型和时—温等效原理 17 2.6玻耳兹曼叠加原理 19 2.7高聚物的非线性粘弹性 19 第三章 拉伸实验 20 前言 20 3.1拉伸试验简介 20 3.2实验设计 21 1.实验方案的选择 21 2.试样的制备 21 3.方法的设计 22 4..测试注意事项 23 3.3.应力应变滞后圈的绘制 23 1.1#材料在不同的应变速率下的应力应变之后圈 24 2. 35#材料在不同应变速率下的应力应变滞后圈 25 3