Identification of Flexural Rigidity and Tension of Short Hangers with Adding Mass and Neural Network

The effect of flexural rigidity on natural frequency is great for short hangers. Hence, the flexural rigidity of hangers should also be identified besides the basic frequency in determination of hanger tension.Utilizing the significant effect of mass on natural frequency, the additional mass method (AMM) is proposed, with mass as an additional condition in the identification of hanger tension. According to the measured frequencies of hangers before and after the attachment of the mass., the flexural rigidity and tension of hangers can be estimated using Artificial Neural Network (ANN), which further solves the inverse calculation problem based on the nonlinear relationship among frequency, tension and stiffness. A group of short hangers with lengths in the range of 2-10 m are studied as the cases. Results show that the AMM is proved to be feasible in tension and flexural rigidity identification, and the ANN also gets validated in nonlinear inverse calculation.