粘弹性阻尼材料及夹层板阻尼结构动态力学性能研究

发布时间：2018-06-22 11:38

本文选题：粘弹性阻尼材料 + 约束阻尼夹层板结构　；参考：《青岛理工大学》2016年硕士论文

【摘要】：粘弹性阻尼材料(VEM)和约束阻尼夹层板(CLD)结构广泛应用在船舶、航空航天、机械制造等领域的振动控制。本文主要研究了Qtech 501粘弹性阻尼材料和Qtech 413粘弹性阻尼材料两种阻尼材料(以下简称Qtech 501和Qtech 413)的基本性能,借助动态粘弹谱仪测试(DMA)研究了上述材料的动态阻尼性能,并对实验数据进行拟合。通过单点锤击实验,着重研究了弹性支撑和固定端约束两种边界条件下的夹层板阻尼结构复合损耗因子,同时分析了阻尼层厚度、约束层厚度、约束层材料对复合损耗因子和阻尼效率的影响。首先研究了两种粘弹性阻尼材料的基本性能,包括固化时间、固含量、密度、硬度、拉伸强度和断裂伸长率。Qtech 501和Qtech 413的固含量分别为97.58%和94.76%,均属于快速固化高固含量环保型材料;Qtech 501和Qtech 413的密度分别为1.140g/cm3和0.997g/cm3,作为阻尼材料对结构质量影响小;分析两种材料的硬度、拉伸强度和断裂伸长率,结果表明Qtech 501的力学行为更多地表现粘性,而Qtech 413更多的表现弹性。以Qtech 413为例,利用DMA研究了粘弹性阻尼材料的动态力学性能,分析了温度和频率对材料阻尼性能的影响。频率一定时,随温度升高储能模量降低,损耗因子先增后减,Tg时取得峰值;温度一定时,频率越高,储能模量越高,Tg越高,损耗因子峰值随之变大。利用温频等效原理,以折算频率为自变量,以储能模量和损耗因子因变量,对动态力学性能进行拟合。储能模量和损耗因子拟合的决定系数分别为0.999和0.996,残差平方和分别为1.767和3.469×10-4,说明拟合的公式具有很高的精度。对于弹性支撑夹层板阻尼结构,振动持时集中在0.14~0.18s;0.3mm阻尼层结构复合损耗因子最小而0.7mm阻尼层结构复合损耗因子最大;约束层为1mm的钢板结构时0.5mm阻尼层效率最高,其他结构阻尼层效率变化的整体趋势是0.3mm最大,0.5mm阻尼效率次之,0.7mm阻尼层的阻尼效率最差,即呈现阻尼层越薄,阻尼效率越高的规律;铝质约束层材料比钢质约束层材料的阻尼效率要高很多,前者约为后者的4~8倍;约束层阻尼效率随着厚度增加呈现下降的趋势,约束层的阻尼效率最高的为1mm铝板,三个厚度阻尼层的效率分别5.47%,7.02%,7.48%,最差的是3mm钢板;对于特定约束层材料,随着约束层厚度、阻尼层厚度的增加,结构振动级值整体呈现减小的趋势。固端约束夹层板阻尼结构振动持时同样集中在0.14~0.18s;对于以钢板和铝板为约束层材料时,对应的最优阻尼层厚度分别是0.7mm和0.3mm,约束层材料为聚丙烯和有机玻璃时,阻尼层最优厚度为0.5mm;不同结构阻尼层的阻尼效率变化规律一致,阻尼层越薄,效率越高,平均阻尼层厚度效率最高的结构是0.3mm阻尼层、2mm铝板约束层结构,最高值为58.4%;对于特定的约束层材料,当阻尼层厚度相同时,约束层越薄,阻尼效率越高;聚丙烯和有机玻璃由于材料损耗因子的影响,结构整体的复合损耗因子和阻尼效率比金属约束层要高,钢板,铝板,有机玻璃和聚丙烯约束层最高效率分别为1.33%,6.49%,17.49%,18.99%;当约束层材料一定时,随着约束层厚度的增加,结构振动总级值不断减小,而受边界条件的影响,随着阻尼层厚度的增加,结构加速度响应规律不明显。研究结果表明,在约束阻尼结构设计时,约束层的模量和刚度应与基层匹配,同时约束层也应具有较高损耗因子。一方面通过增大中间阻尼层的剪切变形,而增大结构耗能能力,另一方面增大约束层损耗因子也有助于增加结构的损耗因子,从而更好地进行振动控制。
[Abstract]:Viscoelastic damping material (VEM) and constrained damping sandwich (CLD) structure are widely used in the vibration control of ships, aerospace and mechanical manufacturing. This paper mainly studies the basic properties of two kinds of damping materials (Qtech 501 viscoelastic damping material and Qtech 413 viscoelastic damping material (hereinafter referred to as Qtech 501 and Qtech 413), with the aid of the dynamics. The dynamic damping properties of the above materials are studied by viscoelastic spectrometer (DMA), and the experimental data are fitted. Through a single point hammer test, the composite loss factors of the sandwich plate damping structure under two boundary conditions of elastic support and fixed end are studied. At the same time, the thickness of the damping layer, the thickness of the confinement layer and the material of the constrained layer are analyzed. The basic properties of two viscoelastic damping materials are studied, including curing time, solid content, density, hardness, tensile strength and elongation at break.Qtech 501 and Qtech 413, respectively, 97.58% and 94.76%, respectively, which are fast curing and high solid content environmental protection materials; Qtech 501 and Qtech 41. The density of 3 is 1.140g/cm3 and 0.997g/cm3 respectively. As a damping material, the influence of the structure quality is small. The hardness, tensile strength and elongation at break of the two materials are analyzed. The results show that the mechanical behavior of Qtech 501 is more viscous, while Qtech 413 shows more elasticity. The viscoelastic damping material is studied by DMA in the case of Qtech 413. Dynamic mechanical properties, and analyze the influence of temperature and frequency on material damping performance. When the frequency is certain, the storage modulus decreases with the temperature, the loss factor increases first and then decreases, and the peak value is obtained in Tg. When the temperature is certain, the higher the frequency, the higher the storage modulus, the higher the Tg, the peak of the loss factor. The conversion frequency is calculated by the principle of the equivalent temperature and frequency. The dynamic mechanical properties are fitted with the variable of energy storage modulus and loss factor. The determination coefficients of the fitting of energy storage modulus and loss factor are 0.999 and 0.996 respectively, and the sum of residual squares is 1.767 and 3.469 * 10-4 respectively, indicating that the fitting formula is of high precision. In 0.14~0.18s, the composite loss factor of the 0.3mm damping layer is the smallest and the composite loss factor of the 0.7mm damping layer is the largest. The 0.5mm damping layer is the highest when the steel plate structure with the constraint layer is 1mm, the overall trend of the other structure damping layer efficiency is the largest 0.3mm, the 0.5mm damping efficiency is the second, the damping efficiency of the 0.7mm damping layer is the worst, that is to say, the damping layer of the 0.7mm is the worst. The thinner the damping layer is, the higher the damping efficiency is, the damping efficiency of the aluminum confinement material is much higher than that of the steel constraint layer, the former is about 4~8 times of the latter, the damping efficiency of the restraint layer decreases with the increase of the thickness, the damping efficiency of the constraint layer is 1mm aluminum, the efficiency of the three thickness damping layers is 5.47%, 7. respectively. 02%, 7.48%, the worst is the 3mm steel plate; for the specific constrained layer material, with the increase of the thickness of the constraint layer and the thickness of the damping layer, the vibration level of the structure decreases as a whole. The vibration holding of the sandwich plate damping structure is also concentrated in the 0.14~0.18s; for the steel plate and the aluminum plate as the constrained layer material, the corresponding optimum damping layer thickness The optimum thickness of the damping layer is 0.5mm when the confinement material is polypropylene and organic glass. The damping efficiency of different structural damping layers is the same, the damping layer is thinner, the efficiency is higher, the structure with the highest thickness efficiency of the average damping layer is the 0.3mm damping layer, the 2mm aluminum plate constraint layer structure is 58.4%; for special, the structure of the 2mm aluminum plate is 58.4%. When the thickness of the damping layer is the same, the damping efficiency is higher when the thickness of the damping layer is the same, the higher the damping efficiency is, the composite loss factor and the damping efficiency of the polypropylene and organic glass are higher than that of the metal confinement layer. The maximum efficiency of the steel plate, aluminum plate, organic glass and polypropylene is 1.33%, 6.49%, 17. respectively. 49%, 18.99%, when the constraint layer material is certain, with the increase of the thickness of the constraint layer, the total value of the structural vibration decreases continuously, and the response law of the structure acceleration is not obvious with the influence of the boundary conditions. The time constraint layer should also have a high loss factor. On the one hand, the energy dissipation capacity of the structure is increased by increasing the shear deformation of the middle damping layer. On the other hand, increasing the loss factor of the constraint layer also helps to increase the loss factor of the structure, so that the vibration control is better.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB535.1

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