1. University Assistant, Institute for Mechanics of Materials and Structures, Vienna Univ. of Technology, A-1040 Vienna, Austria (corresponding author). E-mail: bernhard.pichler@tuwien.ac.at
2. Associate Professor, Institute for Mechanics of Materials and Structures, Vienna Univ. of Technology, A-1040 Vienna, Austria.
3. Professor, Institute for Mechanics of Materials and Structures, Vienna Univ. of Technology, A-1040 Vienna, Austria.
4. Professor, Head of the Institute for Mechanics of Materials and Structures, Vienna Univ. of Technology, A-1040 Vienna, Austria.