蜂窝夹层复合材料不确定性参数识别方法

Parameter identification approach of honeycomb sandwich composite with uncertainties

提出蜂窝夹层复合材料不确定性参数识别方法。采用三明治夹芯板理论建立铝蜂窝夹层结构的初始有限元模型,其中芯层等效弹性参数由均匀化方法计算。据芯层结构及相对灵敏度分析,选存在不确定性且对动态特性敏感性较大的面外剪切模量及面板厚度为待识别参数。对6块铝蜂窝复合材料板进行自由-自由边界条件下动态试验,获得试验模态参数的均值及标准差。据试验结果采用所提方法识别铝蜂窝夹层板不确定性参数。结果表明,对存在不确定性参数的铝蜂窝夹层复合材料用该方法能准确识别参数的均值及标准差,并建立具有准确统计意义的动力学模型。

An approach of parameter identification for predicting uncertainties in honeycomb sandwich composite is provided.The initial finite element model of a honeycomb plate is constructed by the application of an appropriate sandwich theory,in which the equivalent parameters were predicted by homogenization method.According to the analysis of the internal honeycomb structure and the relative sensitivity of eigenvalues with respect to system parameters,the sensitive parameters including the uncertainties （Gcxz,Gcyz and thickness of the face sheet）are selected to be identified. Through modal experiments of six different honeycomb plates with free-free boundary condition,the mean values and deviations of the modal frequencies are obtained,using which the uncertain parameter identification of honeycomb sandwich plate is conducted.Identification results show that when considering the uncertainty in honeycomb sandwich composite,the proposed identification method can be used for accurately identifying the mean values and deviations of the uncertain parameters and the dynamical finite element model with statistical significance can be constructed.