Designing and manufacturing structures of all kinds in an economic and a safe way is not possible without doing experimental stress analysis. The modernity of structures, with their higher reliability demands, as well as today's more stringent safety rules and extreme environmental conditions necessitate the improvement of the measuring technique and the introduction of new ones. Although theoretical/mathematical analysis is improving enormously, an example of which is the finite element model, it cannot replace experimental analysis and vice versa. Moreover, the mathematical analysis needs...