DAMAGE ASSESSMENT OF BEAMS USING AN ARTIFICIAL NEURAL NETWORK AND NATURAL FREQUENCIES. - Tufisi, Cristian; Gillich, Gilbert-Rainer; Popescu, Cristinel; Ardeljan, Mario (Annals of 'Constantin Brancusi' University of Targu-Jiu. Engineering Series / Analele Universităţii Constantin Brâncuşi din Târgu-Jiu. Seria Inginerie, 2021)