Numerical Analysis, Experimental Study And Software Development Of Pre-stressed Diagonal On Square Composite Space Truss

Prestressed composite space truss (PCST) is a new kind of space structurecomposed of steel cables, steel tubes and reinforced concrete ribbed slabs and it is avery practical structure which could not only make good use of the material characterthat the concrete is in compression and the steel is in tension, but also reduce thedeflection of the structure with the steel cables. At present the study in this field is justbeing begun in the world and the research is mainly about the static and dynamicbehavior of the PCST. But the problems of the PCST about the optimum pre-tensionvalues in the cables, the vertical seismic analysis and assistant calculating softwaredevelopment, should be analyzed and resolved further more. In this paper, theprestressed diagonal on square composite space truss (PDSCST) is analyzed in detailconsidering the unresolved problem above.Firstly, the numerical simulated method and the basic assumption of the PDSCSTare introduced and the static finite element method and the dynamic finite elementmethod are described simply.Secondly, the static behavior of the PDSCST based on the project of No.1 highschool in Tianjin, is analyzed in detail by the finite element analysis package ofALGOR and the results are compared with the ones of the prestressed square on squareoffset composite space truss (PSSCST). Release Tension Method is introduced and themethod of the optimum pre-tension values in the cables of PCST in practical project isobtained though a mass of calculations.Thirdly, the dynamic behavior of the PDSCST is analyzed in detail. Naturalfrequencies of the PDSCST are calculated and all kinds of influencing factors areanalysed. Simplified formula of the first period is obtained using ternary linearregression fundamentals. The vertical seismic analysis of the PDSCST is carried out indetail in 8 and 9 degree seismic intensity and feasibility of the simplified method isproved.Fourthly, through the model test of the PDSCST, the correctness ofcharacteristics of stress distribution and the feasibility of Release Tension Method areproved.Finally, the assistant calculating software of the PCST is developed using VisualBasic and the internal finite element self-programming is compiled with FORTRAN.The results are compared with the ones of the ALGOR and the correctness of thecalculation model in theALGOR are proved.