In Back-Prestressing Force Frame Work, The Concept Of "Sub-Internal Force" Caused By Prestressing Force And The Method For It

At first, the paper gives several of mechanics characteristics of modern pre-stressedstructures, from which a new definition of concrete's sub-internal force is presented.Based on the new definition, a new method of calculating sub-internal force, whosename is the pre-stress equivalent transformation method, is explained in detail. Thisdesign idea of efficient use of sub-internal force and the new method mentioned abovecould help us to derivate the formulas and equation of sub-internal force for thestructural elements of the same cross-sectional area under the condition of differentbar distribution and different restriction conditions, as well as the formulas ofincorporated internal force considering the effect of sub-internal force.How to put the design of sub-internal force into some engineering project isintroduced in the paper by the comparison with internal force record of realconstruction. Successfully, the new calculation principal for non-viscous pre-stressedbars and some reasonable construction method are suggested to help the real projectconstruct smoothly.By summarizing the analysis method for frame beam, the analysis model of beam ispresented to calculate the mechanics characterizes. After analysis of test model underdifferent forces, paper shows the new calculation method for the beam of pre-stressedframe structures, which is improved by the design of real engineering project.The research of the paper could be the references for other designer to considerthe effect of the sub-internal force into the real design works. In fact, the newconstruction scheme of pre-stressed concrete frame beam has the great economicvalue and more advantage in the real engineering projects.