What is a common sign of internal damage to laminated honeycomb structures?

A common sign of internal damage to laminated honeycomb structures is indeed the presence of pockets of air trapped inside. This occurs when the adhesive bond between the layers of material in the structure fails, creating voids or delaminations. These air pockets indicate that the structural integrity has been compromised, which is critical to understand when evaluating the safety and performance of these materials.

The presence of internal damage, such as these air pockets, can lead to significant reductions in strength and stiffness, which are essential for the intended applications of honeycomb panels in aviation and other industries. Identifying these signs early can be crucial for maintenance and safety protocols, enabling timely repairs before more serious issues develop.

While visible cracks, changes in color, and unusual sounds may indicate other issues, they are not definitive indicators of internal damage specific to laminated honeycomb structures.