碳纤维复合材料切削性能影响因素的分析研究

发布时间：2018-03-31 21:18

本文选题：碳纤维复合材料　切入点：有限元仿真　出处：《中北大学》2017年硕士论文

【摘要】：碳纤维复合材料具有强度高、耐热性与耐腐蚀性好、出色的抗冲击特性以及比重小等优异的性能,现已经广泛的应用于国防、航空航天、汽车等领域。但是由于具有各向异性的特征,以及纤维束的脆性,很容易在切削加工过程中产生毛刺、分层、断裂等缺陷,属于典型的难加工材料,这些加工缺陷也严重制约着加工质量和加工效率。针对这些切削加工存在的问题,本文通过分析纤维的切削机理,运用ABAQUS/Explicit有限元仿真模块建立切削仿真模型,对切削加工中会影响加工效果的比较关键的因素进行逐个分析以优化切削参数,提高加工质量,主要研究内容如下:首先,以单层碳纤维复合材料板为研究对象,建立切削加工中纤维束的受力模型,对受力情况进行说明;分析对不同纤维角度下纤维的切削机理以及切屑的形成机理,在此基础上推导切削力理论计算公式;其次,运用有限元法分析研究切削加工过程,默认切削深度为0.2mm,刀具前角为15,纤维角度为0,刀尖圆角半径为0.01mm通过有限元软件ABAQUS/Explicit建立二元正交切削仿真模型;然后,以二元正交切削仿真模型为基础,将表面粗糙度与切削力作为研究对象,切削深度、纤维角度、刀尖圆角半径和刀具前角作为切削变量,先改变单一变量值探究表面粗糙度和切削力的变化规律,再在单一变量基础上改变另一变量进一步分析观察表面粗糙度和切削力的整体规律变化情况,通过不同变量间的相互作用与影响可以得出不同变量在变化时对表面粗糙度和切削力的不同变化规律,从而可以对变量数值进行优化,为实际切削加工提供一定的理论基础。最后,得出当各变量值一定时,纤维角度为90时的表面加工质量最好,切削力值最小,纤维角度为135时表面加工质量最差,切削力值最大;当变量发生变化时,对应的最大应力值与切削力值呈整体变化趋势;于变量切削深度而言,在取值范围中0.2mm对应的数值最大,0.05mm对应的数值最小,即切削深度越小越好;于变量刀具前角而言,在取值范围中10与20对应的数值较小,40对应的数值最大,即刀具前角应取较小值;于刀尖圆角半径而言,在取值范围中0.01mm对应的数值最大,0.02mm和0.03mm对应的数值较小,即实际加工切削中刀尖圆角半径应取较大值;
[Abstract]:Carbon fiber composites with high strength, heat resistance and corrosion resistance, excellent impact resistance and small proportion of excellent properties, has been widely used in national defense, aerospace, But because of its anisotropic characteristics and the brittleness of fiber bundles, it is easy to produce burr, delamination, fracture and other defects in the cutting process. These defects also seriously restrict the machining quality and efficiency. In view of the problems existing in these cutting processes, this paper analyzes the cutting mechanism of the fiber, and establishes the cutting simulation model by using the ABAQUS/Explicit finite element simulation module. In order to optimize the cutting parameters and improve the machining quality, the key factors affecting the machining effect are analyzed one by one. The main research contents are as follows: firstly, the single-layer carbon fiber composite plate is taken as the research object. The stress model of fiber bundle in cutting machining is established, and the stress situation is explained. The cutting mechanism and chip formation mechanism of fiber under different fiber angles are analyzed, and the theoretical formula of cutting force is deduced. The finite element method is used to analyze the cutting process. The default cutting depth is 0.2 mm, the cutting tool front angle is 15, the fiber angle is 0, and the radius of the cutting tip is 0.01mm. The simulation model of binary orthogonal cutting is established by the finite element software ABAQUS/Explicit. Based on the binary orthogonal cutting simulation model, the surface roughness and cutting force are taken as the research objects. The cutting depth, fiber angle, cutting tip radius and cutting tool front angle are taken as cutting variables. Firstly, the change of surface roughness and cutting force is studied by changing the value of single variable, and then the variation of surface roughness and cutting force is analyzed and observed by changing another variable on the basis of single variable. Through the interaction and influence of different variables, different variation laws of surface roughness and cutting force of different variables can be obtained, and the numerical value of variables can be optimized. Finally, it is concluded that when the fiber angle is 90, the surface processing quality is the best, the cutting force value is the least, and the fiber angle is 135, the surface processing quality is the worst. The value of cutting force is the largest, when the variable changes, the corresponding maximum stress value and cutting force value show an overall change trend, in the variable cutting depth, the value corresponding to the maximum value of 0.05mm corresponding to the 0.2mm value is the smallest in the range of variable cutting. That is, the smaller the cutting depth, the better, in the variable cutting tool front angle, the value corresponding to 10 and 20 is the largest in the range of values, that is, the tool front angle should be smaller; for the radius of the tool tip, In the range of value, the maximum value of 0.01mm corresponds to 0.02mm and the value of 0.03mm is smaller, that is to say, the radius of cutter tip should be larger in actual machining.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ342.742;TB33

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