The objective of this thesis is to develop a nondestructive evaluation method that could accurately locate and size damage in structures. The method is to be based on pre-damage and post-damage strain energies of beam and column elements. The method should apply to 1-D as well as 2-D and 3-D structures with single or multiple damage locations. To achieve the objectives listed above, the following four tasks are addressed: (1) the development of the theoretical foundations of the nondestructive evaluation theory; (2) the validation of the accuracy of the theory using exact structural deformational data generated from the static analysis of F. E. models in SAP2000; (3) the validation of the practical feasibility of the theory using approximated structural deformational data generated from the modal analyses of F.E. models in SAP2000; and (4) the application of the methodology to an existing structure. The numerical simulations of damage indicate that the proposed NDE method can clearly locate damage in the structures and provide an accurate quantitative value of damage severities, even when only a few lower frequencies and mode shapes are known. The field data analysis results indicate that the developed NDE method can locate damage and provide conservative values for damage severity estimations.
