Simplified Analysis And Rapid Design Of Thin- Walled Tube Truss Light-gauge Floor Beam

OSB composite floor is the basic unit of the low-rise cold- formed thin- walled Light-gauge steel building, which consist of tube truss beams and OSB plates. At present, the research methods are limited to the test and finite element methods, but due to the limitation of test and complexity of finite element modeling, the structure model have not been vigorously promoted. In view of this, this paper will propose a simplified calculation method including finite element method and internal force calculating formula for tube truss beam, and a rapid design table for OSB composite floor combined, which is convenient to practical application.Firstly, full-scale tests of tube truss beam and OSB composite floor were tested in this paper, which had even group clips. Through comparing the failure section, failure model of tests, the rusults showed that: failure model of the tube truss beam and OSB composite floor with even group clips was similar to the tube truss beam with odd group clips, which finally failed all due to bending failure of upper rectangular tube. Failure section was slightly different from the odd group, which was transferred to the section between the clips next to the midspan. In addition, by comparing ultimate load and displacement-load relation in the whole loading process, the results showed that OSB could improve ultimate load of tube truss beam appropriately, but had little influence on its rigidity.On the basis of the test, a simplified finite element analysis is carried out about tube truss beam. Frame unit simulates main components of tube truss beam, and spring simulates nodes of rectangle tube and Z clip. From the comparision the result to test, the error range is in a reasonable agreement discrepancies. In addition, a large number of finite element analyses are carred out, considering the span, the length between clips, the thickness of the rectangular tube and the shape of the rectangular tube. Finally, a simplified formulas for calculating the internal force of the control section is proposed.In the end of this paper, combined the analysis results of our teammate Chen Fenfei, the composition effect of OSB composited floor are determined. Based on its result, a simplified design method which enlarges design strength of steel is proposed. According to the actual case, rapid design table of OSB composite floor is proposed directly for the project.