基于能量法的钢框架结构屈曲分析方法

钢框架结构的屈曲分析通常分两个步骤。首先对结构进行线弹性分析得到内力和弯矩,然后对各个杆单元进行屈曲分析和设计,并且考虑初始缺陷产生的影响。目前,许多国家和地区的钢结构设计规范都是依靠杆单元计算长度系数μ来进行屈曲分析,该系数随杆单元的屈曲形式而定,而实际上它的值是近似的。为此,基于能量法从杆单元的初始缺陷引起的初始变形开始对结构进行非线性分析,从而避免了使用计算长度系数μ。

THE BUCKLING ANALYSIS OF STEEL FRAME STRUCTURES BASED ON AN ENERGY APPROACH

The buckling analysis of steel frame structures is usually carried out in two steps. Firstly, a linear-elastic analysis of the structure is performed to obtain the internal forces and moments; secondly, the buckling analysis and design is done for each element and an initial imperfection is taken into account. In most of steel design codes, the buckling analysis is based on the element effective length factor μ, but in fact this factor is not exact. Based on an energy approach, starting from an initial deformation deduced by the initial imperfections of the elements, a non-linear analysis of the structure is performed, which avoids the use of the factor μ.