ABSTRACT
The need for detection of damage conditions of the structures is becoming more evident. Mainly in respect to achieving structures with greater durability and ease of maintenance. In this context, it inserts the need to develop methods for the evaluation of this damage state in a structure.
More generally, the damage can be defined as changes to any system (natural or modified by man), intentionally or not, that negatively affect the current or future performance of the system (Farrar, 2013).
Identification of damage in structures and the degree of intensity that this is provides important advantages in the design and execution of civil works structures. One advantage is the ability to better identify when interventions are needed in the structure so this way you can conveniently perform maintenance on it. Another ability is to estimate the durability of the structure, as regards the remaining useful life to be estimated in accordance with the damage detection method.
There are diverse structures of damage and detection methods. In this study, experimental and comparative application damage detection method by varying the natural frequencies of the structure with the method of stiffness variation is shown.
This work proposes the application of varying hardness method for identifying damage to a beam constituted by concrete. Bending tests were conducted at four points in concrete beams were monitored while the displacement of the center span and the applied force. The method consists of determining indications for detecting damage by estimating stiffness obtained from the basic differential equation of the beam deflection curve which is only valid for materials with elastic and linear behavior and which follows the law of Hooke. The results indicate that despite the simplifications are considered in the theoretical model, it was possible to detect damage in the tested beams and besides, statistical evidence points to good results.
