Damage Detection Of Cantilever Beam Based On Flexibility Matrix

Modern society with the progress of construction technology and high-tech in the application of the building,what's more the efficiency of using land should also been strengthened,the building gradually to the high-level,large span development.And all kinds of structure forms and architectural style have more requirement of the function of the structure that form the construction.The structure that constitutes the building like bearn,slab and column should be able to continue to bear the load.And we should pay more attention to the structure's degree of damage and the ability to continue to work.In addition to it the building use fixed number of year is longer.The old and damaged structure should be good enough to work.So is important to detect the damage of the structure and reinforce it.But all this should base on the location and the degree of the damage is known to people.So a method that can detect the damage efficiently will provide a great help to reinforce the structure.In this paper we will explore the method that used to detect the damage based on the existing research results and consider the problem that appear in the engineering structure damage test.Then we will put forward a new method that based on flexibility matrix to detect the damage.And demonstrate the feasibility and advantage of this method that detect the damage in structure.In order to conclude the advantages of the method that use flexibility matrix for damage detectioa We will compare with several current common used detect method,and point out their advantages and disadvantages.Finally based on the concrete finite element theory,using the finite element analysis software ANSYS,to build a cantilever beam model that have custom constitutive relation.Then use the software to do the modal analysis of the model beam,to get the natural frequency and the vibration mode of the beam that under the constraint.Then use the frequency and the vibration mode to calculate the flexibility matrix.After that,we decrease the elasticity modulus in the beam to simulate the damage,and then increase the number or the deep of the damage.So that we can get different flexibility matrix at different situations.At last we use the flexibility matrix to construct damage identification index to identify the damage of the structure.