Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

a sandwich panel is a kind of composite material, which is usually made of two components: a small outside layer (which is the same on both sides), and an inside layer, which is used to get certain properties, for example insulation or fire resistance.
sandwich panel

"hail to the chief" is the official presidential anthem of the united states.
hail to the chief

he is more often called davy crockett.

davy crockett