Application of dynamic system identification to timber beams. I

In this first part of a two-part paper, development of a method of dynamic system identification for timber beams is presented with an analytical veri fication of the method using a finite-element model. A method of global non destructive evaluation for identifying local damage and decay in timber bea ms is investigated in this paper. Experimental modal analysis is used in co njunction with a previously developed damage localization algorithm. The da mage localization algorithm utilizes changes in modal strain energy between the mode shapes of a calibrated model, representing the undamaged state of the beam of interest, and the experimentally obtained mode shapes for a ti mber beam. Analytical evaluations were performed to demonstrate and verify the use of this method of global nondestructive evaluation for the localiza tion of damage or decay in timber beams. In a companion paper, experimental laboratory tests are presented that verify the use of dynamic system ident ification to locate damage within timber beams.