A procedure for in situ wind load reconstruction from structural response only based on field testing data

The field application of a proposed procedure for the wind load identification is presented. The wind loads is inversely reconstructed from measured structural response in time domain, using an augmented impulse response matrix. The inherent noise amplification, arising from the ill-conditioning associated with the inverse problem, is resolved by means of Tikhonov regularization scheme in conjunction with two techniques for optimal regularization parameter estimation. To increase the accuracy along with the availability of the measured response only at a limited number of sensor locations, the problem is projected onto the modal coordinates. The structural modal parameters are obtained by an operational modal analysis technique. The case study of this paper is a 9.1 m (30 ft) tall guyed mast. Numerical simulation was implemented by finite element modeling of the mast and a realistic two dimensional multivariate fluctuating wind speeds, to verify the experimental results by analogy. The results are provided in time and frequency domain. Comparison of the experimental results with the numerical simulation, where actual loads are available, confirm the capability of the proposed method. Based on the existing analogy, the reconstructed wind load in higher modes, derived from different regularization parameter estimation techniques, can also be validated.