Wang Xing-Guo, Wu Wen-Lin, Huang Zhi-Cheng, Chang Jun-Jie, Wu Nan-Xing
School of Mechanical and Electronic Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, China.
Key Lab of Nondestructive Testing, Ministry of Education, Nanchang Hangkong University, Nanchang 330063, China.
Materials (Basel). 2018 Feb 21;11(2):310. doi: 10.3390/ma11020310.
The ultrasonic transmission spectrum in a double-layered bonded structure is related closely to its interfacial stiffness. Consequently, researching the regularity of the transmission spectrum is of significant interest in evaluating the integrity of the bonded structure. Based on the spring model and the potential function theory, a theoretical model is developed by the transfer matrix method to predict the transmission spectrum in a double-layered bonded structure. Some shift rules of the transmission peaks are obtained by numerical calculation of this model with different substrates. The results show that the resonant transmission peaks move towards a higher frequency with the increase of the normal interfacial stiffness, and each of them has different movement distances with the increasing interfacial stiffness. Indeed, it is also observed that the movement starting points of these peaks are at the specific frequency at which the thickness of either substrate plate equals an integral multiple of half a wavelength. The results from measuring the bonding specimens, which have different interfacial properties and different substrates in this experiment, are utilized to verify the theoretical analysis. Though the theory of "starting points" is not demonstrated effectively, the shift direction and distance exactly match with the result from the theoretical algorithm.
双层粘结结构中的超声传输谱与其界面刚度密切相关。因此，研究传输谱的规律对于评估粘结结构的完整性具有重要意义。基于弹簧模型和势函数理论，采用传递矩阵法建立了一个理论模型，用于预测双层粘结结构中的传输谱。通过对该模型在不同基体材料下进行数值计算，得到了传输峰的一些移动规律。结果表明，随着法向界面刚度的增加，共振传输峰向高频方向移动，且每个峰随界面刚度增加的移动距离不同。实际上，还观察到这些峰的移动起始点位于特定频率处，此时任一基体板的厚度等于半波长的整数倍。在本实验中，利用对具有不同界面特性和不同基体材料的粘结试样进行测量的结果来验证理论分析。尽管“起始点”理论未得到有效证明，但其移动方向和距离与理论算法的结果完全匹配。
