The Experimental Study Of Damage Detection Of Circular Arch Based On Strain Mode

Cracks present a serious threat to the performance of structures since most of the structural failures are due to material fatigue.For this reason,methods allowing early detection of cracks have been the subject of intensive investigation,which help management the structure and reducing the cost for refinement.Theoretical derivation,numerical simulation and model test were synthetically applied in this paper.Some studies and progresses about dynamic responses for damage detection are introduced.The strain mode method is utilized to identify the arch structure damages.Four contents are expounded as follows.(1) The vibration-based methods of damage detection are reviewed and summarized.The background and development trend in this field are surveyed,in particular by means of strain mode.(2) The theory of vibration of circular arch in the plane is presented.And the methods of damage detection which are based on displacement mode and strain mode are also summarized.(3) The circular arches with different damage configurations are simulated by using ANSYS code.A general law about the relationship between crack locations or degree and modal parameters is obtained.Compared with displacement mode,the strain mode is more sensitive to the damage changes.(4) An experimental study on the circular arch in undamaged and several damaged configurations is carried out.After using a CMIF procedure by MATLAB to identify structural modal parameters,the comparison between experimental results and those obtained by means of numerical simulation methods is listed.Good agreement between them is observed.An identification procedure based on strain mode measurements is proposed and validated.