1. Univ. of the German Armed Forces Munich, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany (corresponding author).
2. Professor of Structural Engineering, Univ. of the German Armed Forces Munich, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany; and President, International Association of Protective Structures, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany.