Damage Identification Of Beam-type Structures With The Improved Element Damage Variable Based On Data Fusion

The bridge health monitoring system has the characteristics of obtainingcontinuous data （the monitoring system can provide enough monitoring data along thetime axis）. Usually deterministic identification method is unable to realize accuratepositioning injury using datas with different levels of noise by the experiments ofapplying different levels of noise in the modal parameters,and at the same time angleinformation of the structure is also difficult to measure. This paper explores thefeasibility of a method of damage identification by the combination of damage indicesand probability, to solve the problems that the current structure damage identificationindex has bad noise immunity in the structural damage detection. Mainly include thefollowing contents:①Through the tectonic theory and improved method of dynamic fingerprintsdamage index------element damage variable D,this papers Introduce to extract themodal of rotational components by static condensation method. The beam-type modelsis generated through ansys software,and the same of the detection of vibrantinformation. Angle information of the structure is measured through verticaldisplacement with the static condensation method. In this process, the estimation of thestructural parameters is needless.We can directly export the relationship ofdisplacements and angles without unrecognized parameters through dynamic equationsof motion of general structure with multi-degree of freedom and the method of "virtualstructure". By using this method to reconstruct the angle information.②As accurately as possible to obtain the system parameters to be identified using amodal analysis method with high precision—SSI. Proposed a improved damageidentification index through the combination of probabilistic methods-DS theory andelement damage identification index.To investigate the effect of noise, damage locationand extent of damage on damage identification through applicating different levels ofnoise into the signals obtained by finite element simulation.To test the effectiveness ofthe improved damage identification index.③To do the vibration testing of rectangular simply supported beams. First,extracting the before and after damage modal parameters of the first three-order of thesimply supported beams using SSI. Then using the improved damage identificationindex for the damage localization of the simply supported beams.Further validate the feasibility and superiority of the improved damage index applied to the actual structuraldamage identification...