Since the topological insulator concept was expanded from the field of quantum waves to the field of elastic waves, the research related to the elastic system valley Hall insulator has been developed rapidly because of its novel physical properties, rich design ability for wave modulation and simple implementation conditions. To address the limitations of small energy and inflexible structure of the edge-state transmission of valley Hall insulators in traditional structure, a topological waveguide heterostructure is designed based on the valley locking principle. The original configuration of this structure features a honeycomb lattice connected by rectangular veins. The energy band structure and transmission characteristics of the model are calculated using the equivalent structural parameter method. It is found that there are three Dirac points at the corner point K of the Brillouin zone, and the spatial inversion symmetry of the system can be broken by changing the structural parameters, so as to realize the topological phase transition of the out-of-plane body elastic mode in three frequency bands. The topological heterogeneous structure is formed by superimposing Dirac point phonon crystals between two topological insulators, and the topological waveguide state possesses advantages, such as multiband, tunability, and robustness. The structure can be used to design energy splitters and energy convergers to achieve flexible manipulation of elastic waves. This study enriches topological acoustics, and the designed multi-band elastic topological insulator has potential applications in multi-band communication and information processing.
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