Dynamic response of single lap joints, subjected to a harmonic peeling load is studied theoretically and experimentally. In the theoretical part, dynamic response of a single lap joint clamped at one end and subjected to a harmonic peeling load at the other end is investigated. Adherents are modeled as Euler-Bernouli beams joined in the lap area by a viscoelastic adhesive layer. Both axial and transverse deformations of adherents are considered in deriving the equations of motion. The effects of adhesive layer thickness, mechanical properties and its loss factor on the dynamic response of the joint are investigated. Furthermore, effects of defects such as a void in the lap area on the dynamic response of the joints are studied. The results showed that frequencies where peak amplitudes occurred were little dependent on the adhesive loss factor. However, peak amplitudes reduced for joints with a higher adhesive loss factor. Furthermore, the results indicated that for the joint geometries and properties investigated the system resonant frequencies were not affected by the presence of a central void covering up to 80% of the overlap length. In the experimental part, single lap joints were fabricated using 6061 -T6 Aluminum. Adherents were joined together using Hysol EA 9689 adhesive film. Joints with various central voids were manufacture by removing adhesive film from the desired area of lap joints prior to bonding adherents. Dynamic responses of the joints were investigated using the hammer test technique. The system response was measured using both an accelerometer and a non-contact laser vibrometer. The natural frequencies of the joints obtained by using the laser vibrometer were very close to those obtained theoretically. However, natural frequencies obtained by using an accelerometer depended on the accelerometer location in the system, which was attributed to its mass contribution to the over all system mass. A central void covering less than 80% of the overlap length had little effect on the system resonance frequencies. This was in agreement with the theoretical results. In contrast, total system-damping ratios were a function of the void size. Joints without a void exhibited higher damping.
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机译：从理论上和实验研究了单圈接头的动态响应，经受谐波剥离载荷。在理论部分中，研究了单端夹紧的单圈接头的动态响应并在另一端进行谐波剥离负载。被建模的欧拉 - 伯纳梁通过粘弹性粘合剂层建模。在导出运动方程中，考虑了轴向和横向变形的轴向和横向变形。研究了粘合剂层厚度，机械性能及其损耗因子对接头的动态响应的影响。此外，研究了在接头的动态响应上的液体区域中的缺陷的效果。结果表明，峰值发生的频率几乎依赖于粘合剂损耗因子。然而，具有较高粘合剂损耗因子的关节的峰值幅度降低。此外，结果表明，对于关节几何和性质，研究了系统谐振频率不受中央空隙的存在影响，其覆盖高达80％的重叠长度。在实验部分中，使用6061 -T6铝制造单圈接头。使用Hysol EA 9689粘合剂膜连接在一起。具有各种中央空隙的关节通过在粘合粘合剂之前从所需的LAP关节区域除去粘合剂膜来制造。使用锤子试验技术研究了关节的动态响应。使用加速度计和非接触式激光振动计测量系统响应。通过使用激光振动器获得的关节的固有频率非常接近理论上获得的那些。然而，通过使用加速度计获得的自然频率依赖于系统中的加速度计位置，这归因于其对所有系统质量的大规模贡献。覆盖小于80％的重叠长度的中央空隙对系统共振频率影响不大。这与理论结果一致。相反，总系统阻尼比率是空隙尺寸的函数。没有空隙的关节表现出更高的阻尼。
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