Research On Floor-Truss-Interaction For Staggered Truss System

The staggered truss system is a new style structure system, which has been analyzed theoretically and applied into some projects internationally. It's found that Floor-Truss-Interaction research is in a blank field both at home and abroad. And the combination of floor and truss is the key member in the staggered truss system. The paper is emphasized on researching the static character of the staggered truss system considering floor deformations and shear studs slips. The main researches are outlined as the following:1) The tectonic connections of the staggered truss system has been gone deep into research. It involve the connections between trusses and columns, typical connections of the truss node, the connections between trussed and floors, the connections between trusses and border beams, and selecting the typical members of staggered truss system relating to design.2) The matrix displacement method is used to investigate the effect of the floor deformations and shear connectors slips on the displacement and forces of staggered truss system under the horizontal loads. Compare with the result of no considering floor deformations and shear connectors slips, the dissertation concludes that the axial forces of column have no essential variations, the variations of moments and floors' relative displacement cannot be neglected.3) The floor and truss, which are connected by shear connectors, will interact under the vertical loads. Based on the basic elasticity theory, this paper set up the Ordinary Differential Equations (ODE) between axial force Nc1 of upside concrete plank, axial force Nc2 of downside concrete plank and the section shear V according to the Bernoulli's hypothesis. The forces of the members and the slip can be solved by solving the Ordinary Differential Equations (ODE) through the Runge-Kutta method.4) The finite element method (FEM) is a useful way to analyse structure composing of floor and truss in the staggered truss system and to prove the result of the theory analysis. This paper sets up the FEM model of the composite structure through ANSYS, simulates the floor, truss, shear connector by the shell, rigid frame and connector elements. The connector elements are the key in the FEM analysis and this paper set up the connector elements by three upright springs. In the last, this paper proves the validity of the theoryresult through the result of the ANS YS program.