Fig. 1. Schematic diagram of a large-size sandwich transducer: (a) Not grooved; (b) grooved. Inset is a schematic diagram of the grooved method.大尺寸夹心式换能器示意图　(a)未开槽; (b)开槽, 插图为开槽方式示意图

Fig. 2. Large-size sandwich transducer vibration diagram.大尺寸夹心式换能器振型图

Fig. 3. Vibration transmission characteristic curves of large-size sandwich transducer: (a) Change the groove height; (b) change the groove width.大尺寸夹心式换能器的振动传输特性曲线　(a)改变槽高; (b)改变槽宽

Fig. 4. Resonance and anti-resonance frequency of a large-size sandwich transducer: (a) Change the groove height; (b) change the groove width.大尺寸夹心式换能器的共振及反共振频率　(a)改变槽高; (b)改变槽宽

Fig. 5. Schematic diagram of the emission voltage response curve of the transducer.换能器的发射电压响应曲线示意图

Fig. 6. Bandwidth of a large-size sandwich transducer: (a) Change the groove height; (b) change the groove width.大尺寸夹心式换能器的带宽　(a)改变槽高; (b)改变槽宽

Fig. 7. Schematic diagram of the radiation surface section of the large-size sandwich transducer.大尺寸夹心式换能器辐射面截线示意图

Fig. 8. End face displacement distribution of large-size sandwich transducer: (a) Change the groove height; (b) change the groove width.大尺寸夹心式换能器的端面位移分布　(a)改变槽高; (b)改变槽宽