Numerical And Experimental Study On Damage Detection Of Cable-net Structure

Nowadays the tension structure has a wide-ranging using due to the development oftechnology. Since the long term of the structural service time, the environmental and otherfactors will lead to the damage or even accidents. In order to ensure the structural safety, thedamagedetectionofcivilengineeringstructuresisparticularlyessential.Anew signal processing method called Hilbert-Huang Transform (HHT) is used in thispaper to detect the damage of cable-net. First, the basic theory of HHT is described in detail,and then several numerical signals are analyzed byHHT.The results show that this methodisapplicable to nonlinear and non-stationary process. Nonlinear finite element method is alsoused to analyze the cable element, and the form-finding of two cable-nets is working out byANSYS.In this paper, the numerical simulation of the intact and damaged cable-net structure isstudied by ANSYS, and the parameters change in static and dynamic is observed. By theresults of the HHT transform, the marginal Hilbert spectrum changes with the degree andlocationofthedamage.Thedamageindicebased onthemarginal Hilbert spectrum is verifiedto be sensitive to the damge by the simulation of cable-net. The damage extent and theapproximatelocationofthenonlinearstructurecanbeidentificatedbyusingthismethod.A scale model test of cable-net is done and the result shows that the structuredemonstrates strong non-linearity. The partial cable looseness of the cable-net is also studied,using HHT transform processing to analyze the acceleration signal, the amplitude of theHilbert marginal spectrum of the damaged structure is larger than the one of the intactstructure. The results coincide with the simulation results. It proves that using this method toevaluatedamageofthecable-netstructureprobabilityhasfeasibilityandcredibility.