Nomograms For Determination Of Effective Length Of The Unregular Frames

Determining the frame column effective length is a key part of the structure stability calculation in practical engineering. This specification for design of steel structure and specification for design of concrete are given in some relevant calculation formula and forms, but these formulas and tables can only be applied to the simple situation. In the complex situation, such as the frame column axial force and height is large., the formula is not applicable, may leads to unsafe results. In this paper. the formulas are deduced by using second-order displacement method in order to solve these problems, and the chart for determining the effective length is also obtained. The chart can be used to calculate the effective length factor quickly and concisely.Axial force is discussed in this paper, we use second-order displacement method and column high column of different structure buckling buckling characteristic equation and based on it make sure the calculation length of frame column chart, it is these charts, not only convenient for scholars can easily find the exact calculation length, also can very clearly see the parameters variation trend.In order to determine the accuracy of the chart, comparing with the existing national standards at the same time, also need to use the software ANSYS for simulating calculation of this bar, and the analytical calculation and software analysis and calculation results are compared, to verify that it is correct.