【作者】 杨俊杰；

【导师】 沈军；

【作者基本信息】 哈尔滨工程大学 ， 材料学， 2010， 硕士

【摘要】 由于具有比刚度比强度高等优异的力学性能,纤维增强树脂基复合材料结构在航空航天、海洋工程及汽车等各种民用领域具有广泛而重要的应用。而树脂基体的高阻尼特性和复合材料本身的各向异性使得这种先进复合材料同时展现出优良的阻尼特性,比普通金属高1-2个数量级。近年来,对于复合材料结构阻尼的设计与研究已逐渐引起人们的重视。本研究即针对目前对于复合材料结构阻尼性能日益增长的工程需求,采用悬臂梁法和有限元设计相结合的方法对复合材料板簧结构阻尼性能进行了系统的试验研究和理论分析。制备了不同铺层角度的玻璃纤维/环氧、玻璃纤维/增韧环氧和碳纤维/增韧环氧共九组复合材料单向板与复合材料板簧结构试件,进行了各项力学性能试验与振动阻尼性能试验。对复合材料单向板及其板簧结构阻尼特征进行了试验研究,并根据半功率带宽-Matlab法,对实时设备显示图数据作进一步分析处理,获得准确的半功率带宽值,再通过理论公式计算最终获得复合材料单向板及其板簧结构阻尼性能(损耗因子)。在有限元分析过程中,根据有限元模态应变能量法和复合材料结构力学理论,建立了复合材料板簧结构阻尼分析的极限状态方程。在试验基础上,编制了基于ANSYS软件的有限元设计分析软件,实现了复合材料板簧结构阻尼性能的有限元分析与设计。并将理论结果与试验结果进行对比分析,两者吻合较好。在有限元分析的基础上,进一步分析了不同铺层和不同材料组成(包括不同纤维和基体)对于复合材料结构阻尼性能的影响。并通过理论分析获得其最优铺层。本文试验和理论分析结果对于力学性能和阻尼性能两者兼顾的复合材料结构设计与分析具有一定的理论和实际应用价值。更多还原

【Abstract】 Fiber reinforced polymer-matrix composites are widely used in aerospace, marine engineering and various civil applications, such as automobiles and so on, due to their exceptionally high specific stiffness and strength. The composites are known to exhibit material damping one or two orders higher than most common metals as a result of the high damping of polymer matrices and the material heterogeneity. And the significance of the damping to the dynamic performance of composites structures is broadly recognized in the recent years. Under the circumstances of high requirement to the structural damping of the composites in the engineering applications, the systemically experimental and theoretical study on the vibratioanl damping of the composites was accomplished in this paper, based on the cantilever beam method and the Finite Elemental Analysis (FEA).Nine groups of laminae and leaf springs made of glass-fiber/epoxy resin, glass-fiber/toughened epoxy resin and carbon-fiber/toughened epoxy resin were manufactured, and different mechanical experiments and vibrational damping tests were performed. The experimental tests were conducted to obtain the mechanical parameters and damping parameters of the laminae and leaf springs. And a half-power bandwidth-Matlab method was used to get the exact values of half-power bandwidth, according to the actural curves from the detectors. And the loss factors of the composite laminae and leaf springs were finally obtained through the calculation by equations. In the finite elemental analysis, the limit state equation for damping analysis of the composite leaf spring structure was set up according to the mode strain energy method and composite structural mechanics. On the basis of experimental results, numerical simulation procedure for the finite elemental analysis based on ANSYS software was complied, which realize the finite elemental design and analysis for the structural damping of the fiber reinforced polymer-matrix composite leaf springs. Good agreement was shown in the comparison between the analytical and experimental results.The study on the effect of the different layout and different constituents (including fiber and matrix) on the structural damping of the composites were further performed. Finally, the optimal layout was obtained as a result of the theoretical analysis. The experimental and theoretical results in the paper will be valuable to the composite structural design with high requirements both to the mechanical and damping performance.更多还原