箱型截面齐次广义屈服函数的数值拟合及极限承载力分析

HOMOGENEOUS GENERALIZED YIELD FUNCTION FITTING AND ULTIMATE BEARING CAPACITY ANALYSIS OF STRUCTURES WITH BOX SECTION

推导了箱型截面全截面屈服时轴力和弯矩之间的隐式相关关系,揭示了影响相关关系的2个考虑厚度的无量纲几何参数及其影响规律,据此通过数值拟合建立了箱形截面的齐次广义屈服函数,给出了常用箱型截面齐次广义屈服函数待定系数表,进而结合数值齐次广义屈服函数和弹性模量缩减法,提出了箱型结构的极限承载力分析方法,克服了原广义屈服函数参数选取不合理、齐次广义屈服函数式通用性差、结构极限承载力计算精度欠佳等问题。算例分析表明,采用此方法求解结构极限承载力具有良好的计算精度、计算效率和迭代稳定性。

The implicit correlation between axial force and bending moment for box section was derived,and two nondimensional geometrical parameters considering thickness that determine generalized yield function（ GYF） were revealed,as well as their influence laws. Then a coefficient values table of the homogeneous generalized yield function（ HGYF） for box section was established. Combined with the above numerical simulation of HGYF and elastic modulus reduction method,a method for ultimate bearing capacity analysis of structures with box section was put forward. The method could solve some important problems,such as the unsuitable factor and a less of commonly applicable in GYF,the results in the ultimate bearing capacity analysis of engineering structures were varied with different initial loads. The numerical examples showed that the proposed method based on numerical simulation of HGYF had good calculation accuracy,computational efficiency and iterative stability for solving the ultimate bearing capacity of structures.