Experimental evidence of large complete bandgaps in zig-zag lattice structures.

In this paper, experimental evidence of large complete bandgaps in a kind of light-weighted zig-zag lattice structure (ZLS) is presented. Ultrasonic experiments are conducted on the stainless steel slab designed with ZLS to detect the complete bandgaps. Also, the numerical simulations of the experiments by the finite element method are carried out. For comparison, we conduct the same experiments and numerical simulations on the stainless steel slab with straight lattice structure (SLS). Good agreement is obtained between the experimental and numerical results. The complete bandgaps of ZLS are successfully tested and no complete bandgap is found in SLS. The band structures and vibration modes of both ZLS and SLS are calculated via the finite element method to understand the experimental data. The effects of the geometry parameters of ZLS on the complete bandgaps are discussed in detail.