Phononic crystals and acoustic metamaterials have attracted many researchers by reason of unconventional acoustic behaviors which can be applied to achieve wave propagation control. To enhance the application value of acoustic behaviors, period structures with adaptive control ability have been an investigation focus. In the present paper, an innovative manipulation method based on inhomogeneous and periodic thermal field for longitudinal wave (P-wave) band gap control is proposed and investigated. A three-dimensional solid model, consist of homogeneous thermal sensitive material, can be transferred into functionally graded phononic crystals by a series of metallic films which are periodically embedded in structure and play the role of heat sources. Based on laminated model and transfer matrix method, propagation characteristics of both normal incident and oblique incident P-wave in functionally graded crystals are investigated. Numerical band structure results from analytical method, validated by simulation result via COMSOL Multiphysics software and transmission spectra result, reveal that period thermal field owns the ability to affectively tune the band gap properties including band width and band gap location. Also, transmission spectra result indicates that the attenuation of wave propagation may be inconspicuous even there exists obvious but relatively narrow stop band gaps. The present research proposes a band gap tuning method on P-wave according to the application of period thermal field and may lay theoretical and simulation foundation for designing and fabrication of tunable vibration isolators and acoustic filters.

声子晶体和声学超材料由于非常规声学行为可用于实现波传播控制而吸引了许多研究人员。为了提高声学行为的应用价值，具有自适应控制能力的周期结构一直是研究的重点。在本文中，提出并研究了一种基于非均匀和周期性热场的用于纵波（P 波）带隙控制的创新操纵方法。由均质热敏材料组成的三维立体模型，可以通过一系列周期性嵌入结构中并起到热源作用的金属薄膜转化为功能梯度声子晶体。基于叠层模型和传递矩阵法，研究了功能梯度晶体中垂直入射和斜入射 P 波的传播特性。分析方法的数值能带结构结果，通过 COMSOL Multiphysics 软件的模拟结果和透射光谱结果进行验证，表明周期热场具有有效调节带隙特性的能力，包括带宽和带隙位置。此外，透射谱结果表明，即使存在明显但相对较窄的阻带隙，波传播的衰减也可能不明显。本研究根据周期热场的应用提出了一种P波带隙调谐方法，可为可调谐隔振器和声滤波器的设计和制造奠定理论和仿真基础。