Finite Element Analysis On Strengthening Compression Columns By Pre-stress

When introducing simply the strengthening methods in the country at present, the method of prestressed strengthening was discussed with emphasis in the application of the structure strengthening.In the text, the modeling method of finite element analysis was explained in brief, and these world-famous common programs of that were also analyzed. The computation software, SUPER-SAP 13.0 of Windows, which was most suitable to the text, was presented as well as the properties and the functions.On the basis of the test design of the concrete column under axial compression by prestressed strengthening, the finite element models were set up in details including the models selecting, units compartmentalizing, loading design, materials properties and boundary conditions. Then according to the compare and analysis of simulative results, theory calculation and testing data, the feasibility of simulating the axis compressed member is verified by the finite element method. It can be extended to the finite element simulation of the member under eccentricity compression.For the sake of grasping completely the performance of component under eccentricity compression by prestressed strengthening method, the eccentricity loading components under the different value of prestressed forces and the change of eccentricity distance were designed in details on basis of the bearing properties of it. These kinds of designs were computed by finite element simulation method, and these results were also analyzed in details. Under kinds of conditions, these stresses, strains and their development of concrete, steel, and angle iron were shown. During the whole process, the rate of sharing the loading for the angle iron was also indicated.These results demonstrate that the effect of improving the bearing load of structure is very good by strengthening the member of eccentricity compression under pre-stress. The ultimate bearing capacity of strengthened column is closely related to the eccentricity distance. In the condition of eliminating the lagging strain of angle iron, the magnitude of pre-stress putting on the angle iron has litter impact on the ultimate bearing capacity of structure. To the particular case under the small eccentricity compression, the method that theangle irons are strengthened on two-sides, but pre-stress is only put one side, can be adopted firstly. It may take a supplement for the criterion of the strengthening technology of concrete structure (CESC25f:90).