中文摘要：

针对均匀升温热环境下夹芯梁的声振特性进行了研究。建立了考虑热应力、横向剪切效应、转动惯量影响的夹芯梁振动方程,获得了简支夹芯梁在热环境下振动响应的理论解;通过瑞利积分得到远场声压。结果表明,夹芯梁内存在热应力时,各阶固有频率均下降,速度、辐射声压级、声功率响应曲线均向低频方向漂移,声辐射效率变化不明显。通过与数值仿真结果对比,验证了本文的热预应力夹芯梁声振耦合响应理论分析方法的可行性。此外,本文还分析了不同芯材厚度和弹性模量对夹芯梁声振特性的影响。研究发现,芯层增厚或者软化均会降低整个结构的刚度。

英文摘要：

The vibro-acoustic characteristics of sandwich beams in thermal environment are studied in this paper. The governing equation of flexural vibration for sandwich beam is derived with considering the effects of thermal stresses, transversal shear and rotational inertia. The vibration responses are solved, and the radiation sound pressure for far field of the heated beam is obtained via Rayleigh integral. The results indicate that the natural frequencies of sandwich beams decreases in thermal environment, and the response curves shift toward lower frequency range. Radiation efficiency of the heated beam is not affected obviously by thermal stresses. The influence of the thickness and elastic modulus of core layer is also studied. Finite element analysis is also carried out as validation. Theoretical solutions and simulation results show good agreements.