To fabricate a joint in a panel, a groove is generated and the panel is bent along the groove. The panel includes a first skin, second skin, and core. The core is sandwiched between the first skin and the second skin. The groove passes through the first skin and at least a portion of the core. The groove includes a set of tabs and a corresponding set of slots. The set of tabs intermesh with the set of slots in response to bending the panel along the groove.