Sikdar Shirsendu, Banerjee Sauvik
Civil Engineering Department, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Civil Engineering Department, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Ultrasonics. 2016 Sep;71:86-97. doi: 10.1016/j.ultras.2016.05.025. Epub 2016 May 31.
A coordinated theoretical, numerical and experimental study is carried out in an effort to interpret the characteristics of propagating guided Lamb wave modes in presence of a high-density (HD) core region in a honeycomb composite sandwich structure (HCSS). Initially, a two-dimensional (2D) semi-analytical model based on the global matrix method is used to study the response and dispersion characteristics of the HCSS with a soft core. Due to the complex structural characteristics, the study of guided wave (GW) propagation in HCSS with HD-core region inherently poses many challenges. Therefore, a numerical simulation of GW propagation in the HCSS with and without the HD-core region is carried out, using surface-bonded piezoelectric wafer transducer (PWT) network. From the numerical results, it is observed that the presence of HD-core significantly decreases both the group velocity and the amplitude of the received GW signal. Laboratory experiments are then conducted in order to verify the theoretical and numerical results. A good agreement between the theoretical, numerical and experimental results is observed in all the cases studied. An extensive parametric study is also carried out for a range of HD-core sizes and densities in order to study the effect due to the change in size and density of the HD zone on the characteristics of propagating GW modes. It is found that the amplitudes and group velocities of the GW modes decrease with the increase in HD-core width and density.
开展了一项协调一致的理论、数值和实验研究，旨在解释在蜂窝复合夹层结构（HCSS）中存在高密度（HD）核心区域时传播的导波兰姆波模式的特性。最初，基于全局矩阵法的二维（2D）半解析模型被用于研究具有软芯的HCSS的响应和色散特性。由于结构特征复杂，研究具有HD核心区域的HCSS中的导波（GW）传播本身就带来了许多挑战。因此，使用表面粘结压电晶片换能器（PWT）网络对有和没有HD核心区域的HCSS中的GW传播进行了数值模拟。从数值结果可以看出，HD核心的存在显著降低了接收的GW信号的群速度和幅度。然后进行了实验室实验以验证理论和数值结果。在所研究的所有情况下，理论、数值和实验结果之间都观察到了良好的一致性。还针对一系列HD核心尺寸和密度进行了广泛的参数研究，以研究HD区域尺寸和密度的变化对传播的GW模式特性的影响。发现GW模式的幅度和群速度随着HD核心宽度和密度的增加而降低。
