Study On Secondary Moment And Redistribution Of Internal Force About Continus Prestressing Concrete Hollow-core Slabs With Cold-drawn Low Carbon Wires

At first, this thesis analyzes the main causes in theory, which have effects on the redistribution of internal force and modulation of moment for the partially contious prestressing Concrete hollow-core slabs with cold-drawn low carbon wires, including the relative height of compressive zone of section ,the tensioning stress. Then analyzes the seven partially contious, twosimply supported full-scale prestressing Concrete hollow-core slabs with cold-drawn low carbon wires,are test.Based on the fact that the cracking effect exists in reinforced and prestressing menber cracking seltions, the bi-folded plane hypothesis is presented in this paper. And based on the bi-folded plane hypothesis, this paper presents the micro-element converted stiffness method for nonlinear analysis of structure. The analysis program is designed.The results of nonlinear analysis are good agreement with the ones test.So the method of nonlinear analysis is proved reliable and practical. Using this article test data, inferred outside has carried the bending moment design valueΜ_load sum which of the inferior bending momentΜsecpulled with causes (Μ_load+Μ_sec) is the amplitude modulation object, take the relative plastic cornerθph0 as the independent variable bending moment amplitude modulationβcoefficient function expression.Then, with the program , two-span prestressing Concrete hollow-core slabs with cold-drawn low carbon wires are simulated. Some conclusions are reached with the taking into account theξ,secondary moment :(1) Theξin the the partially contious slab effect the dectility of the section and rotary property of the plastic hinge. So total coefficient of the modulation of moment becomes less with theξbecoming bigger.(2) The tensioning stress by changing the secondary moment,and then affects the redistribution of internal force of he partially contious prestressing Concrete hollow-core slabs with cold-drawn low carbon wires structures. If prestressed structure can not complete full redistribution of internal force,ultimate load may put off and put up because of secondary moment. Total coefficient of modulation of moment also is bigger.