Damage Detection Of Frames Using The Changes In The Beam-column Joint Rotation

In recent years, with economic development, structure safety problems are drawingextensive attention, and damage detection of structures is becoming a hot research topicwhich people show great concern about. The static identification methods as thecommonly used methods in structure condition assessment are usually simple, intuitiveand easily implemented, which means that the static identification methods have practicalvalue in the actual engineering application. For the widely used framework structure, thispaper presents a damage detection method using the changes in the beam-column jointrotation.First, the paper gives a simplified model to quantify the structural lateral stiffness. Toformulate the lateral stiffness of the frame, the frame is first divided into individual storeys,and the stiffness of the individual columns is summed to form the stiffness of the storey.Next, the expression of the beam-column joint rotation of the plane frame under static loadis derived based on the anti-bending point method and the accuracy of the expression isdemonstrated by using numerical examples. Then, sensitivity analysis of beam-columnjoint rotation in the plane frame is carried out. The changes in the beam-column jointrotation were found to well reflect the local damage in the frame and a damage detectionmethod is proposed using the change amount of beam-column joint rotation (CAOBCR)and the change rate of beam-column joint rotation (CROBCR) as the damageidentification parameters. The detection method first use the CAOBCR to predict theapproximate damage location, then further amend the damage location based on theprevious result and finally identify the damage extent by using the CROBCR. Numericalexamples show that the damage identification of different structural models by the methodpresented in the paper are all successful. For multi-story and multi-span plane fames, theCAOBCR and CROBCR can accurately reflect the type, location and damage extent of the damage member. The validity of the method is demonstrated. At the end of this article,the deficiencies of the proposed method are analyzed and the next step of the researchwork is carried out.