Panel structure, door panel, and method of manufacturing panel structure

A door panel, comprising:

• a panel structure including a core plate disposed between first and second surface plates forming a pair of, wherein
• the core plate has a plurality of protrusions arranged in a matrix on a first main surface thereof facing the first surface plate,
• each of the plurality of protrusions has a protrusion tip surface facing the first surface plate, and
• the core material and the first surface plate are bonded to each other such that each of the protrusion tip surfaces is in contact with the first surface plate and is constrained by a plurality of planar separate constraint regions corresponding to a planar shape of said each protrusion tip surface.

A method of manufacturing a panel structure including a core plate disposed between first and second surface plates forming a pair, wherein

• the core plate has a plurality of protrusions arranged in a matrix on a first main surface thereof facing the first surface plate,
• each of the plurality of protrusions has a protrusion tip surface facing the first surface plate,
• the method comprising:
• a bonding step of bonding the core plate to the first surface plate such that each of the protrusion tip surfaces is in contact with the first surface material and is constrained by a plurality of planar separate constraint regions corresponding to a planar shape of said each protrusion tip surface.