Method of making a reinforced composite panel of the cellular-core sandwich type, and a panel obtained by performing such a method

A method of making a locally reinforced composite panel of the sandwich type having a cellular core, said method being characterized in that:

• a stack is formed that is made up of:
• at least one first skin (110) made of a reinforced thermoplastics material;
• a first reinforcing ply (120) made of a reinforced thermoplastics material;
• a cellular core (130) made of a thermoplastics material;
• a second reinforcing ply (140) made of a reinforced thermoplastics material;
• and a second skin (150) made of a reinforced thermoplastics material;
• each of the first and second reinforcing plies (120, 140) having a surface area that is smaller than a surface area of each of the first and second skins (110, 150), and said first and second reinforcing plies being positioned symmetrical with respect to a plane formed by the cellular core at places against said skins which are predetermined to be subjected to greatest mechanical stresses;
• the stack is pre-assembled;
• the pre-assembled stack is heated in an oven;
• and
• said panel is formed by subjecting the heated stack to cold-pressing in a mold, under a pressure lying in the range 1×106 Pa to 3×106 Pa in a single step of molding so that high production throughput is provided and the panel is optimally strengthened locally without suffering from any extra weight.