Experimental And Method Study On Damage Identification Based On Structure Vibration

As the development of the society and the progress of technology, modern projectstructures are proceeding at the direction of maximization, complication. Thecomplicated environments of service threat functional safety of the structure. Thedamage accumulates, which may lead to catastrophic failures causing costly repair orheavy loss of human lives. Consequently, the structure damage identification using thechanges of their vibration characteristics has become a hot research topic.In this paper, various damage identification methods based on changes ofvibration characteristics are summarized. The shortcoming of existing damageidentification method is presented. The principle of damage identification methodbased on curvature modal is introduced. Numerical simulation in case of a beamcontaining damage indicat that mid-span of beam is good fit to the principle but beamnear support do not fit to the principle as well as mid-span and the reason of thedifferent is analyzed.Fot the different near beam support, a simply method for damage identification incolumn structures based on axial vibration analysis is presented. The fundamentalaxial vibration mode of a damage column is analyzed using axial vibration theory andboth the location and degree of the damage are estimated. The viability of theproposed method is investigated both numerical simulation and experimentally in caseof a column containing crack. In the light of the results obtained, the advantages andlimitations of the proposed method as well as suggestions for practical engineering arepresented and discussed.Through the relationship of stiffness, curvature and acceleration, a simply methodfor damage identification based on acceleration signal is presented. The vibrationacceleration signal of a damage structure is analyzed using vibration theory and boththe location and degree of the damage are estimated. The viability of the proposedmethod is investigated by numerical simulation in case of a frame containing damage.Acceleration signal is used directly rather than modal analysis, so damageindentification work become easier.As a summery, a two-step damage identification method is present for high-riseframe. The process of damage identification is divided into two steps. The first step isto located the story of the damage and the second step is to find out the damage structure members. Numerical simulation in case of a twelve stories frame containingdamage shows that this method can easily locate damage.