Finite Element Simulation Analysis On Stressed Skin Diaphragm Of Light-weight Steel Structures

Light-weight steel structures, which are made up of panel and light structural steel frame, have been widely used in various sorts of industry buildings, public buildings and residential buildings. It is difficult to systemically analyze diaphragm action theoretically for complexity and difficulty of establishment of mechanical analysis model of stressed skin. Although a lot of research and experiments on the performance of stressed skin have been carried out in the world, but the past research work was mostly focused on skin diaphragms, especially on the connection between clad shells or between clad shells and their sustaining bars while there was few research and experiment on the buildings with clad structure as a whole. This paper analyzes the mechanism of stress diaphragm action, reviews the theoretical and experimental researches on stressed skin effect, makes the whole numerical simulation analysis and studies on the stressed skin structure models by using finite element software STAAD/CHINA on the basis of conventional steel light structure model.This paper firstly designs a conventional steel light structure model without considering stressed skin effect according to current standard. By canceling roof braces and column braces, arranging diaphragms of roof, fastigium and longitudinal wall, enlarging purlin spacing, changing connection modes between frame beam and column, adopting different pattern and thickness of panels, nine different models are set up. By simplifying the structural models, and choosing five sorts of primary combinations of action effects, the reasonable calculation models are achieved. This paper makes some initial analysis of the distribution of diaphragm stress and frame member internal force, maximum of stress and internal force, the situation of structural deformation and horizontal displacement of columntop and rooftop, further makes compare with the corresponding calculation result of the conventional steel light structure model without considering stressed skin action, some primary conclusions are drawn: (1) Considering the stressed skin action, the distribution laws of axial force^ shearing force and bending moment of frame members are changed, and the internal force of members correspondingly decrease; (2) the stressed skin action reduces the deformation of loaded structure and increases the stiffness of the whole buildings obviously; (3) Some distribution laws of the diaphragm stress of stressed skin structures can be easily summarized; (4) The analysis result of the stressed skin structural models with unstable plane frame system is similar to the ordinary stressed skin structural models', but considering the safety of the whole construction process, rigid or semi-rigid connection between frame beam and column ought to be made. On the basis of above conclusions, this paper summarizes some cautions to practical design and construction of light-weight steel structures, and some useful suggestions are put forward, and can function as references to practical design and construction of light-weight steel structures.