Johanna Sjölund

A new approach for determining the hidden material parameters of a honeycomb

An optimization method to obtain the cell wall properties of Nomex honeycomb material is presented. There, the outcomes of physical experiments and micromechanical simulations are compared in an effort to identify the geometric or/and material parameters for the best match. Only the cell wall thickness and Young’s modulus, called here as the hidden parameters, are used in the matching as the Young’s modulus is difficult measure reliably. The mean values and standard deviations of the geometric parameters of the cell structure model are obtained through image analysis. In the micromechanical model used, the cell walls are considered as linearly elastic Bernoulli beams. The optimum hidden parameter values for the Nomex case turn out not to be unique but they appear in a combination known as the bending stiffness.