Crush core forming: An innovative technology to manufacture structural sandwich parts with variable thickness

Sandwich structures, constituted in honeycomb core and skin in composite material, are usually employed to produce parts having a constant thickness or simple shape. Indeed, sandwich components with complex shapes, curvature or varying thickness are costly to manufacture due to the preliminary machining operations required on the core prior the molding process. A novel approach to manufacture complex sandwich structures, knows as Crush Core Forming (CCF) process, consisting in press-forming simultaneously the core material and the skins into the shape is under study. Such a method is potentially able to increase the production rate and lowering the overall costs. The present work aims to develop an experimental route to produce sandwich panels by means of CCF process and build a FE model of the forming process and validate it against the experimental studies. Experimental study was conducted to derive the fundamental parameters and properties for core and skins to be added in the FEM model of the CCF process. After, the numerical model was implemented to simulate the forming of the core and skins. Finally, a laboratory scale sandwich part was produced to validate the model outputs and assessing the reliability of the proposed approach.