Experimental Validation of the Proposed SHM Technique form Limited Extracted Dynamic Responses of a Steel Beam Adopting Inverse Dynamic Approach

Abstract

Condition monitoring of structures is important from safety consideration. Damage detection techniques, using inverse dynamic approaches, are important tools to improve the mathematical models for structural health monitoring. However, uncertainties in the measured data might lead to unreliable identification of damage in structural system. The measurement of dynamic responses at all degrees of freedom of a structure is also not feasible in practice. An analysis methodology is proposed for condition monitoring of beam structures in the framework of finite element model with limited randomly measured dynamic responses. The structural properties viz. axial rigidity and bending rigidity are identified at the element level in the updated models of the system. Damage detection technique is employed considering the uncertainties associated with the measured dynamic responses data. The proposed model is suitable for practical problem, as it is able to identify the structural parameters with limited modal data of first few modes, measured at selected degrees of freedom. Different numerical examples with various damage scenarios are explored to demonstrate the applicability of the proposed model. The model is able to identify the structural damage with greater accuracy from the noisy dynamic responses even if the extent of damage is small. Experimental studies, on simple cantilever beams, establish the potential of the proposed methods for its practical implementation.