芳纶纤维复合材料加工过程中的热力行为研究

发布时间：2018-01-16 15:25

本文关键词：芳纶纤维复合材料加工过程中的热力行为研究　出处：《大连理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：芳纶纤维复合材料具有高韧性、高强度、低密度和抗冲击等性能特点,在航空航天、军工等领域内的应用日趋广泛。然而,芳纶纤维复合材料各向异性、层间强度较低,同时芳纶纤维的强韧性和低导热性使其成为典型的难加工材料,加工过程中极易产生毛边、分层、撕裂、热损伤等加工缺陷,这也成为了制约芳纶纤维复合材料应用和产品使役性能的瓶颈难题之一本文以层铺结构芳纶纤维复合材料为研究对象,结合国家自然基金“高强高韧复合材料加工过程力热耦合作用机理及损伤消减策略”,开展了芳纶纤维复合材料加工过程中的热力行为研究。本文从芳纶复合材料的材料特性分析入手,对芳纶复合材料加工缺陷形态、类型进行了归纳总结,并进行了加工缺陷的成因分析。采用划切试验的方法,观测了平铺材料划痕的形成过程,分析了芳纶纤维的破坏特点,并通过改变切削条件观测了划切质量及划切力的变化规律,采用硬质合金麻花钻对芳纶复合材料进行了制孔试验研究,进一步验证了划切试验取得的结论。树脂基体在温度过高时存在玻璃化现象,而芳纶复合材料导热系数极低,加工易产生热损伤,而加工过程中切削热形成的温度场分布规律至今仍未被揭示。本文针对芳纶纤维复合材料加工条件较恶劣的钻孔加工,采用热物理参数均匀化方法以及数值解析方法,建立了芳纶纤维复合材料钻削温度场模型,并通过热电偶测温和红外热像仪测温方法对温度场模型进行了验证,结果表明,温度场模型计算值与试验结果值相差在10%以内。本文利用建立的温度场模型对不同加工条件下的温度场分布以及切削区内的温升过程进行了模拟,分析了钻削过程中,钻削深度、转速以及纤维排布方式对温度场的影响规律。本文的研究结果揭示了芳纶纤维复合材料缺陷的形成机理,探索了影响芳纶复合材料加工质量与加工过程中切削力的影响因素,建立了芳纶复合材料钻削加工过程中的温度场分布模型,为芳纶纤维复合材料的高效低损伤加工提供了理论依据和技术基础。
[Abstract]:Aramid fiber composites with high toughness, high strength, low density and impact resistance are widely used in aerospace, military industry and other fields. However, aramid fiber composites are anisotropic. The interlaminar strength is low, at the same time, aramid fiber becomes a typical refractory material because of its strength and toughness and low thermal conductivity. It is easy to produce processing defects such as edge, delamination, tear, thermal damage and so on. This has also become one of the bottleneck problems that restrict the application and performance of aramid fiber composites. In this paper, laminated aramid fiber composites are the research object. Combined with the National Natural Fund, "the mechanism of mechanical and thermal coupling and damage reduction strategy of high strength and high toughness composites during processing". The thermal behavior of aramid fiber composites was studied in this paper. Based on the analysis of material characteristics of aramid fiber composites, the morphology and types of processing defects of aramid fiber composites were summarized. The forming process of the scratch of tile material was observed and the damage characteristics of aramid fiber were analyzed. By changing the cutting conditions, the change of cutting mass and cutting force was observed, and the hole making test of aramid composites was carried out by using cemented carbide twist drill. The conclusion obtained from the cutting test is further verified. When the temperature of resin matrix is too high, there is glass phenomenon, while the thermal conductivity of aramid composites is very low, and the thermal damage is easy to occur in processing. However, the distribution of temperature field formed by cutting heat has not been revealed yet. In this paper, the drilling processing of aramid fiber composites with poor processing conditions has not been revealed. The model of drilling temperature field of aramid fiber composites was established by using the method of homogenization of thermal physical parameters and numerical analysis, and the model was verified by thermocouple and infrared thermography. It turns out. The difference between the calculated values of the temperature field model and the experimental results is less than 10%. In this paper, the temperature field distribution and the temperature rise process in the cutting zone under different processing conditions are simulated by using the established temperature field model. The effects of drilling depth, rotation speed and arrangement of fibers on temperature field during drilling are analyzed. The results of this paper reveal the formation mechanism of defects in aramid fiber composites. The influence factors on the processing quality and cutting force of aramid composites were explored, and the temperature field distribution model of aramid composites during drilling was established. It provides a theoretical and technical basis for the processing of aramid fiber composites with high efficiency and low damage.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB33;TQ342

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