Optimal design and performance testing of phononic crystal acoustic barriers

The rapid development of highway traffic leads to the continuous deterioration of the acoustic environment along the route. The phononic crystal theory provides innovative ideas for the design of transportation sound barriers. However, the popularization and application of phononic crystal-based acoustic barriers (SCABs) have been limited by the lack of practical numerical modeling and field test validation. In this study, the noise reduction performance of SCAB is evaluated through field tests. The results show that, compared with conventional concrete acoustic barriers (CABs), SCABs exhibit superior acoustic attenuation performance in the bandgap range, with noise reduction enhancement in the bandgap ranging from 0.5 to 2.1 dB(A), especially in the local peak region of the highway noise spectrum. However, in terms of overall insertion loss, CAB outperforms SCAB at all protection distances.For in-depth study, a three-dimensional finite element model is established based on the freeway site conditions and verified by measured data. Compared with the 2D model, the 3D model is more advantageous in considering top diffraction and ground reflection, which have a significant effect on the noise reduction effect. This work not only provides field test support for the application of SCAB in traffic noise control, but also gives design guidelines.