Research On Damage Identification And Location Method Based On Residual Force Vector Method

It is a frontier subject in the field of civil engineering to identify the structural damage through the dynamic or static parameters of the structure.Residual force vector method is one of the most important damage identification methods,however,the existing residual force vector methods are based on dynamic response parameters,and the normalized mode data must be used,its application scope is limited,In view of this,this paper further studies the residual force vector method,an improved dynamic residual force vector method under ambient excitation is proposed,which can directly use non normalized mode data;In addition,a static residual force vector method is proposed,which is suitable for structural damage identification under static test:Firstly,the existing dynamic residual force vector method is improved.By introducing the balance parameters and health index before and after damage,the non normalized vibration mode data under environmental excitation can be directly used,and the improved residual force vector equation is derived.Through the numerical example of truss structure,two different damage elements are simulated to verify this method.The results show that this method can accurately identify the damage location.Moreover,an experimental model of steel truss is made,and the dynamic test under environmental excitation is carried out.According to the collected data,the improved residual force vector method is further verified.Secondly,a static residual force vector method is proposed for structural damage identification.Based on the displacement data of static test and the stiffness matrix of finite element model,the static residual force vector is derived.It is proved that the position of non-zero element in the vector corresponds to the degree of freedom of the damaged element node.Based on this principle,the damage position of the structure can be identified,and an algebraic solution to the damage degree is proposed.In addition,in view of the fact that it is difficult to measure the rotational degree of freedom in the actual structure,the model condensation technique is combined with the static residual vector method,and only the translation degree of freedom data of incomplete test can be used for calculation.Examples of truss structure and beam structure are used to verify the proposed method,and the results show that the proposed method is reasonable and reliable.