The Analysis And Research For Torsional Of Prestressed Steel-Concrete Composite Beams

Pre-stressed composite beams can be used to save steel, reduce the dead weight, lower structural height, increase load-capacity of construction and bridges structures. And more importantly, as a result of the pre-stress existence, it enhances the yielding load, increases stiffness, reduces the distortion of the components under the same load.In our country, the research on the component torsion developed quite late. At present, the performance of the concrete component under the torque is still not fully understood; and the only small number of people has done some research work on the torsional strength of composite beam. Moreover, the research on torsional analysis for the pre-stressed composite beam is still backward. Therefore, to carry on theoretical analysis of the performance for the pre-stressed composite beam under the combined forces of bending, shear and torsion, has an important practical significance as well as a broad application prospect, which is not only for the actual request to design and calculate the pre-stressed composite beam, but for the urgent need to consummate the analysis theory of composite beam. In a word, without doubt, it has the theoretical and the practical sense.This thesis, taking the pre-stressed steel-concrete composite beam as the engineering object, using the correlative theory method (the softened truss model theory, the modified diagonal compression field theory and the plate-truss model theory) as the premise, studies the torsional strength of the pre-stressed steel-concrete composite beam, and confirms the achieved results by the ANSYS software.The first chapter discusses the subject's background and the practical significance, outlines the origin, application and development of pre-stressed composite beam, summarizes the domestic and foreign research on the mechanical properties of the pre-stressed composite beam, the structural torsional theory development, and shows the primary coverage and key problems in the thesis. The second chapter, based on the softened-truss model theory and the specification...