Analytical and Numerical Modeling of Aramid Honeycomb Cores

Aramid honeycomb cores are widely used in combination with composite face sheets for various sandwich structure applications due to their exceptional stiffness-to-weight ratio. Although numerical simulation techniques for the material and failure behavior of composite skins are well-established, modeling the honeycomb core continues to present a challenge. For detailed analysis, the honeycomb core is often modelled at meso-scale using shell elements, with geometry and material properties evaluated through a combination of tests and assumptions. However, this approach becomes computationally expensive for simulating large structures. In this study, a new method is presented where the honeycomb core is homogenized using orthotropic solid elements, incorporating an advanced material and failure model. The effective core material properties used in the model were determined for an aramid honeycomb core by tension, compression, and shear testing on coupon level. Furthermore, effective material values obtained from analytical calculations were compared with the experimental results to assess the accuracy of the analytical methods. The new developed model was finally validated by four-point-bending testing. This method aims to replace current expensive simulation involving shell elements for the core with a more computationally efficient solution using orthotropic solid elements.