基于一阶剪切变形理论的玻璃纤维增强塑料夹层板模态密度研究

Study of modal density of glass fiber reinforced plastics sandwich plate based on first order shear deformation theory

为提高玻璃纤维增强塑料夹层板宽频带内振声响应特性的计算精度,基于一阶剪切变形理论建立振动控制方程,利用波数空间积分法给出由各向异性薄面板及各向同性夹芯组成的夹层板结构的模态密度解析表达式.通过三通道驱动点导纳实验法对理论模型进行验证分析,讨论了不同设计参数对夹层板模态密度的影响.结果表明:夹层板振动特性在低频段受弯曲刚度控制,高频段面外刚度则是重要影响参数,忽略横向剪切刚度会显著影响夹层板模态密度的估算精度.

In order to improve the computing accuracy of vibro-acoustic properties of glass fiber reinforced plastic sandwich panel in broad band,the vibration control equation was established based on first order shear deformation theory,and an analytical expression for modal density of sandwich plate structures consisting of anisotropic thin coating panels and isotropic sandwich panels was given by using wave number spatial integral method.The mathematical model was verified by using three-channels driving point admittance method.The influences of different design parameters on modal density were discussed systematically.Results indicate that the vibration characteristics of sandwich panel is controlled by bending stiffness for low frequency band,while the out-of plane shear stiffness is the important parameter for high frequency band,and the estimation accuracy of modal density could be influenced significantly without considering the transverse shear stiffness.