玻璃纤维增强复合材料加工机理研究及有限元分析

发布时间：2018-05-11 14:13

本文选题：玻璃纤维增强复合材料 + 钻削机理　；参考：《江苏科技大学》2015年硕士论文

【摘要】：在高精尖的武器装备及航空航天工程领域中均有复合材料的身影。复合材料做为一种新材料,具有轻质高强,防腐性好,抗疲劳性好,耐高温等诸多优异特点,正在逐步撼动传统金属材料的应用领域。但现在复合材料的成型技术,加工技术中还存在诸多难点,对其加工机理的研究也不够透彻。本文对玻璃纤维增强复合材料的钻削过程进行研究与分析,为其进一步的推广和应用提供技术支撑。论文主要研究内容如下:(1)对玻璃纤维增强复合材料的本征特性及力学特性进行了分析。包括:玻璃纤维的特性;玻璃纤维增强复合材料的物理化学性质及常用成型工艺;复合材料弹性力学;复合材料层板失效准则等。(2)以二元直角切削为理论基础,对钻削过程进行了研究,得到了钻削简化模型。通过刀具的受力,对其处于钻心位置、钻头主切削刃位置、钻头最外围的玻璃纤维进行受力分析,得到一系列结论:当纤维方向角与切削方向在0????90?时,切削表面较为平整,断口大致为平滑断口,在90????180?时,切削表面比较粗糙,断口大致为弯曲断口,其主要受到弯曲应力。如果垂直于加工表面的力足够大,玻璃纤维就会受到扭转,在切削力的共同作用下,那可能会产生倾斜断口。通过扫描电镜观察,发现主要断口类型为三种,分别是平滑断口、弯曲断口、倾斜断口,断口类型与玻璃纤维的受力有很大关系。(3)通过有限元仿真技术,对玻璃纤维增强复合材料的钻削过程进行模拟。运用ABAQUS/Explicit模块建立其仿真模型,通过不同工艺参数的仿真试验,得到结论:钻削轴向力随主轴转速增加而减小,随进给速度及钻头直径增加而增加。对2000r/min,120mm/min的钻削过程进行具体分析,在采用Hashin损伤准则的情况下,分析了玻璃纤维增强复合材料的损伤破坏过程。通过后处理模块对其钻削过程中的纤维和基体受力进行分析,发现纤维角度方向和其受力方向一致,且失效过程中,树脂基体将先于玻璃纤维,这与实际情况相同。(4)通过KISLTER测力设备,对玻璃纤维增强复合材料的钻削力进行采集与分析。研究了其在不同工艺参数下钻削力的分布情况,得到钻削轴向力与钻头直径和进给量成正比,与主轴转速呈反比的关系的结论,这与仿真试验相同。通过钻削实验研究了钻削过程中的孔壁表面质量。对加工过程进行总结,得到出入口常见缺陷为毛边,抽丝拉毛劈裂等,内部主要缺陷为粗糙度差,分层现象严重等。
[Abstract]:Composite materials are also found in the sophisticated weaponry and aerospace engineering fields. As a new material, composite material has many excellent characteristics, such as light and high strength, good anticorrosion, good fatigue resistance, high temperature resistance and so on, and is gradually shaking the application field of traditional metal materials. However, there are still many difficulties in the molding technology and processing technology of composite materials, and the research on its processing mechanism is not thorough enough. In this paper, the drilling process of glass fiber reinforced composites is studied and analyzed, which provides technical support for its further promotion and application. The main contents of this paper are as follows: (1) the intrinsic and mechanical properties of glass fiber reinforced composites are analyzed. Including: the characteristics of glass fiber; the physical and chemical properties of glass fiber reinforced composites and the common forming process; the elastic mechanics of composite materials; the failure criteria of composite laminates, etc. The drilling process is studied and a simplified drilling model is obtained. A series of conclusions are obtained by analyzing the force of the tool in the drilling center position, the position of the main cutting edge of the bit and the most peripheral glass fiber of the bit, and a series of conclusions are obtained: when the fiber direction angle and cutting direction are 0 ~ 90? When the cutting surface is flat, the fracture surface is approximately smooth. The cutting surface is rough and the fracture surface is bending fracture, which is mainly subjected to bending stress. If the force perpendicular to the machined surface is large enough, the glass fiber will be torsional, and under the combined action of the cutting force, the inclined fracture may occur. By SEM observation, it is found that there are three main fracture types: smooth fracture, bending fracture, inclined fracture, fracture type and fiberglass stress. The drilling process of glass fiber reinforced composites was simulated. The simulation model is established by using ABAQUS/Explicit module. Through the simulation experiment of different process parameters, it is concluded that the axial force of drilling decreases with the increase of spindle speed, and increases with the increase of feed speed and bit diameter. The drilling process of 2000R / min 120mm / min was analyzed in detail. The damage and failure process of glass fiber reinforced composites was analyzed by using Hashin damage criterion. The stress of fiber and matrix during drilling is analyzed by post-processing module. It is found that the direction of fiber angle is the same as the direction of stress, and the resin matrix will precede the glass fiber during the failure process. The drilling force of glass fiber reinforced composites is collected and analyzed by KISLTER force measuring equipment. The distribution of drilling force under different technological parameters is studied. The conclusion that the drilling axial force is directly proportional to the bit diameter and feed rate and is inversely proportional to the spindle speed is the same as the simulation test. The surface quality of hole wall during drilling is studied by drilling experiments. The common defects in the inlet and outlet are wool edge, drawing and splitting, and the main internal defects are poor roughness and serious delamination.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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