Numerical Simulation of Energy Flow between Insert Elements and Sandwich Panels with Honeycomb Core

Abstract

Sandwich panel structures are widely applied in engineering constructions due to their excellent Ratio between bending stiffness and bending strength. A high specialized structure requires large effort in manufacturing, what in turn leads to high costs. For this reason such structures are restricted to special applications, e.g. space vehicles and racing cars. Sandwich panels consists of a lightweight core which is covered by an upper and lower cover sheets. For the insert installation a hole is required in the sandwich panel. It showed that a slight disturbance of the bore hole center point affects the potting radius which is dependent on the insert hole diameter. As shown the ratio between the insert diameter and the cell size of the core determines the sensitivity of the potting geometry. A method is presented to reduce the uncertainties which arises in the insert installation process. A literature review on the insert elements, their application and Performance is presented. Then, the configuration of the sandwich structures such as assembling, core material and manufacturing are described. A base experimental characterization of the pull-out force of the sandwich panel is presented, where the experimental results are evaluated. A Simulation model using the Finite Element Method is setup. The modeling is extensively described, e.g. modeling of the cover sheet, insert element, potting, core and material definitions as well as the washer and screw force introductions. Finally, the numerical results are presented and compared with the experimental measurements. The occurrence of buckling processes in the simulation fits with analysis data from the experiment. In this way a determination of the linear elastic range and the start of plastic deformation in the core is possible.