The interlayer gap and non-coaxiality in stack drilling
The interlayer gap and non-coaxiality in stack drilling
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叠层钻削中的层间间隙和不同轴度
DOI：
10.1016/j.ijmachtools.2015.09.007
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发表时间：
2015-12-01
影响因子：
14
通讯作者：
Chen, Ken
中科院分区：
文献类型：
--
作者：
Gao, Yuhao;Wu, Dan;Chen, Ken
在大型装配作业中，叠层结构的通孔钻井过程中层间间隙的形成是一个常见的问题。由此产生的界面毛刺和非同轴堆积孔会降低加工质量，增加整体装配时间和成本。本文采用实验和理论相结合的方法，对模拟大型装配体典型结构的宽蒙皮和窄弦叠层结构钻孔过程中的层间间隙形成和非同轴现象进行了研究。首先，专门设计了一些叠层钻孔实验，通过测量上层、下层和界面的孔径，观察叠层孔的非同轴规律；在此基础上，建立了简化的叠层力学模型，研究了叠层钻井过程中层间间隙和非同轴度的形成过程。通过基于简化模型的定量分析，发现叠垛刚度、钻孔推力和压入力对层间间隙和非同轴度有重要影响。最后，采用有限元方法对变形进行三维表示。计算结果与解析简化模型对非共轴性的理论解释一致。此外，根据计算结果，讨论了紧固件和肋的有益作用，从而为更好地设计垛钻提供建议。(C) 2015 Elsevier Ltd.版权所有。
Interlayer gap formation during through-hole drilling in stacked structures is a common problem in large assembly operations. The resulting interfacial burrs and non-coaxial stacked holes deteriorate the machining quality and increase the overall assembly time and costs. This study presents both experimental work and theoretical analysis to understand the interlayer gap formations and non-coaxiality occurrences in the drilling of stacked structures of broad skins and narrow stringers, which imitate typical structures of large assemblies. First, some stack drilling experiments are specially designed and are performed to observe that the stacked holes are non-coaxial in a regular fashion by measuring the hole diameters of the upper layer, lower layer and interface. Then, a simplified mechanical model of the stacks is built in 2-0 to study how the interlayer gaps and non-coaxiality are formed during stack drilling. Through quantitative analysis based on the simplified model, it is noted that the stack stiffness, drilling thrust force and pressing force have important impact on the interlayer gaps and non-coaxiality. Finally, finite element methods are adopted to present the deformations in 3-D. The calculation results agree with the theoretical explanations for non-coaxiality given by the analytical simplified model. In addition, the beneficial effects of the fasteners and ribs are discussed based on the calculation results, and thus, they could contribute to proposals for better designs for stack drilling. (C) 2015 Elsevier Ltd. All rights reserved.