缝合式夹芯结构宽频动力学响应特性研究

Investigation on the broadband dynamic response characteristics of stitched sandwich structure

应用于高速飞行器的缝合式夹芯结构在服役时面临着宽频高强气动噪声载荷,其宽频动力学响应特性分析是飞行器结构设计的关键。针对缝合式夹芯结构推导了基于波有限元的宽频动力学响应预示方法,研究了结构在不同频段内各类型波的传播特性,评估了各波型对结构宽频动力学响应的贡献,揭示了缝合密度及夹芯层厚度对缝合式夹芯结构宽频动力学响应特性的影响规律。研究结果表明:基于波有限元的分析方法能高效准确地预示缝合式夹芯结构的宽频动力学响应;缝线显著增强了缝合式夹芯结构面板与芯层间的整体性,使得结构中高频振动响应幅值显著降低,并对局部模态有显著的抑制效果。

The stitched sandwich structure used in hypersonic aircraft could face high-level broadband aerodynamic noise load during service.The analysis of its broadband dynamic response characteristics is the key to aircraft structure design.A prediction method of wideband dynamic response of stitched sandwich structure based on wave finite element(WFE) theory was derived.The wave propagation characteristics of the stitched sandwich structure in different frequency bands were investigated.The contributions of different waves to the broadband dynamic response were evaluated.The influence of stitch density and the thickness of the sandwich layer on the broadband dynamic response characteristics were discussed.The results show that the prediction method based on wave finite element(WFE) theory can efficiently and accurately predict the broadband dynamic response of the structure.The integrity between the panel and the core layer of the stitched sandwich structure could be significantly enhanced by introducing the sutures.The amplitude of the mid-and high-frequency response is highly reduced and the local mode is significantly suppressed.