Vibration and Sound Transmission Performance of Sandwich Panels with Uniform and Gradient Auxetic Double Arrowhead Honeycomb Cores

Figure 13

STLs of the representative sandwich models: (a) models 1 to 5; (b) models 6 and 7; (c) models 8 and 9. (d) The overall average STLs for the constant-weight sandwich models from 1 to 1500 Hz.