Structural Damage Detection using Best Approximated Dead Load Redistribution

Presented in this article is a novel damage detection method based on best approximation of dead load stress redistribution due to damage. It is a simple, economical, fast, and passive method that requires no artificial means of loading. The measurement is made of strain readings due to dead load at different stages of the structure during its life cycle. The approach is by finding a ‘null plane’, which is a unique identity of each structural member, such that the measurement is closest to its orthogonal projection on this null plane. The detection procedure resembles the process of finding the shortest distance from a point to a plane in elementary geometry. Both theoretical proof with a flexibility formulation and practical procedure with a stiffness formulation are given. The feasibility of the proposed method, together with the false positive test, are studied in a numerical example of a synthetic frame structure. Measurement noise influence is also conducted using perturbed strain measurement.