Measurement of slip and separation in jointed structures with non-flat interfaces
Measurement of slip and separation in jointed structures with non-flat interfaces
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DOI：
10.1016/j.ymssp.2019.106325
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发表时间：
2019-12
影响因子：
8.4
通讯作者：
Wei Chen;M. Jin;I. Lawal;M. Brake;Hanwen Song
中科院分区：
文献类型：
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作者：
Wei Chen;M. Jin;I. Lawal;M. Brake;Hanwen Song
组合结构的非线性动力行为和能量耗散往往归因于结构子部件之间的接触界面。由于缺乏对节理界面的直接测量技术，对节理界面内部的局部运动学行为还没有很好的了解。此外，部分到部分的变化的接口（如表面曲率，表面粗糙度，几何特征，和残余应力）显着影响的结构动力学，因此，引入不确定性的测量响应的连接结构。在本文中，一个连接界面的局部运动学行为的数字图像相关（DIC）测量在振动台激励在前两个共振频率为10个不同的扰动相同的组装结构。对于这些扰动，改变界面曲率以代表典型的制造变化。实验验证表明，DIC方法能够测量滑移和分离的界面与分辨率高达0.23 μm的报告的实验。此外，通过冲击锤试验表征了系统的非线性特性。对于第一模式的结构，分离（拍手）和微观滑移行为进行观察，此外，对于第二模式，宏观滑移运动进行观察。这些结果挑战了节理结构建模中普遍存在的多个假设。
The nonlinear dynamic behavior and energy dissipation of a built-up structure are often attributable to the contact interfaces between the subcomponents of the structure. Due to the lack of direct measurement techniques for jointed interfaces, the local kinematic behaviors inside the interfaces are not well understood. Additionally, the part-to-part variability of the interface (such as surface curvature, surface roughness, geometric features, and residual stress) significantly affects the structural dynamics and, therefore, introduces uncertainty in the measured response of a jointed structure. In this paper, the local kinematic behavior of a jointed interface is measured by digital image correlation (DIC) during shaker excitation at the first two resonant frequencies for 10 different perturbations of the same assembled structure. For these perturbations, the interface curvature is varied to represent typical manufacturing variations. Experimental validation shows that the DIC method is able to measure slip and separation in the interface with a resolution of up to 0.23 μm for the reported experiments. Additionally, the nonlinear properties of the system are characterized via impact hammer test. For the first mode of the structure, separation (clapping) and microslip behaviors are observed; additionally, for the second mode, macroslip motions are observed. These results challenge multiple assumptions prevalent in the modeling of jointed structures.