【摘要】 点阵夹芯板因具有高比强度、高比刚度、强抗冲击性等特点而受到广泛的关注。在结构动态力学性能方面，目前大部分研究仅关注结构整体振动响应，忽略了点阵桁架局部振动特性对结构动态性能的影响，而这种影响正是无损检测方法的基础。为研究点阵夹芯结构局部振动特性和无损检测方法，首先，本文从数值模拟和实验测试2个方面研究点阵桁架对结构中导波传播的影响，并对波信号进行傅里叶分析和小波变换，结果表明波信号会集中在某些峰值。然后，通过分析导波信号和点阵单胞的局部共振模态，证明了波信号频率峰的位置取决于点阵桁架的振动模态频率，尤其是拉压轴向振动模态频率。最后，本文提出了一种利用波信号频率峰位置的变化对点阵桁架进行损伤识别的方法，并通过数值模拟进行了验证，结果表明该方法能有效地检测和定位桁架的损伤。更多还原

【Abstract】 Lattice sandwich structures have drawn considerable attention in engineering applications owing to their exceptional specific strength,specific stiffness,and outstanding impact resistance.Regarding structural dynamic performance,current research predominantly concentrates on global vibration responses while overlooking the influence of local vibration characteristics of lattice trusses on dynamic behavior as fundamental aspects for nondestructive evaluation techniques. This investigation systematically examined the local vibration properties and damage detection methods for lattice sandwich structures.Firstly,combined numerical simulations and experimental measurements were conducted to analyze the effects of lattice trusses on guided wave propagation characteristics.Signal processing through Fourier analysis and wavelet transform revealed distinct energy concentrations at specific frequency peaks.Furthermore,by correlating the guided wave signals with local resonance modes of lattice unit cells,we demonstrated that these characteristic frequency peaks were intrinsically determined by the vibrational modal frequencies of lattice trusses,particularly their axial compression-tension vibration modes. Based on these findings,an innovative damage identification methodology is developed that utilizes the frequency peak shifts in wave signals for structural integrity assessment.The proposed approach is numerically validated,with results confirming its effectiveness in both damage detection and localization for lattice truss structures.更多还原