Vibration-Based Damage Detection in Structural Members Utilizing Finite Elements and Evolutionary Algorithms

Presented within this paper is the application of finite elements method combined with an evolutionary algorithm to the problem of damage detection in structural members using vibration data. The objective is to identify the position of the damage in structure, and to estimate the extent of the damage. To describe the damage, finite element method (FEM) is used here and the damage is modeled as a reduction in the stiffness of the associated element. Using this model, the effect of damage on the vibration characteristics of the structure is studied. The problem of damage detection is then formulated as an optimization problem. The decision variables are the position of damaged element and the extent of damage. The objective function is considered as the difference between measured natural frequencies and those obtained from FE model of the structure. Only natural frequencies are adopted here, because the measurement of mode shapes is usually accompanied by larger amount of error. The proposed damage detection approach is verified and assessed using a simulated cantilever Euler-Bernoulli beam.