Dynamic Experiment And Analytical Study Of Infilled Reinforced Concrete Frames

The infilled frames are the common structure system. Existing research show thatthe infilled walls have great influences on the capacity, stiffness and deformationbehavior of the frames. It is unsafety to ignore the effect of the infilled walls, so it isnecessary to take the effect of the infilled walls into account in the aseismic design ofthe frame in the building structures. With the development of the technology ofnon-destructive methods, the dynamic properties based on vibration technology isused to get the modal parameters of the structure. In this background, the followingresearches are conducted under:1. The modal experiment of a infilled frames with two spans and two bays andfour-story with the scale of 1:3 in laboratory condition. The different positions andquantity in directions and the times of conserve of the infilled walls are tested, Themodal frequency and vibration shape of the structure under all kinds of conditions arediscussed and the sensitive factors influencing the dynamic property of the structureare conducted.2. The different damage identification methods are discussed, such as modalfrequency variety, modal assurance criterion, co-ordinate modal assurance criterion,modal strain energy, modal strain, rigidity change, flexibility matrix, modal curvatureetc. The sensitivity analysis method is adopted to identify the elastic modulus of themodel considering the joint-rotaty of frame, the rectangular finite element wall modelwith angle displacement is modified by two-step identification method to improve theexactness of the research.3. A reasonable explanation of the performance of the structure under seismicloads is given by the analysis of the characteristics of mechanics. The simplifiedmodels of several kinds of infilled frames are compared and are made evaluation. Thefinite element models are built according to the modified frame model, and the resultsare compared with the results of Ansys software to prove the correctness of the model.According to decrease of the modal frequency caused by different times of conserve,The grads method is adopted to correct the stiffness deduction coefficient of the wallto get a reasonable result.