摘要
基于传统广义屈服函数的弹性模量缩减法应用于薄壁结构极限承载力分析时,往往出现计算结果不稳定、精度较低等问题.为此通过理论分析探索了问题的根源,研究建立了工字型截面的齐次广义屈服函数,提出了回归分析的配点遴选原则,通过误差分析确定了齐次多项式的幂次数;根据工字型截面齐次广义屈服函数定义了薄壁构件的单元承载比,利用单元承载比特征分布参数定义了承载比均匀度和基准承载比,为薄壁结构高承载单元的判别提供了动态判据,进而依据变形能守恒原则建立了自适应弹性模量调整策略,建立了工字型薄壁结构极限承载力分析的弹性模量缩减法.算例分析表明,本文方法能准确考虑组合内力对工字型薄壁结构极限承载力的综合影响,得到具有良好稳定性和计算精度的结果.
Unstable and inaccurate results are often encountered when the elastic modulus adjustment method,combined with those classical generalized yielding functions,is employed to evaluate the load bearing capacity of thin-walled structures with I-shaped section. As an attempt to remedy this problem,a homogeneous generalized yielding function( HGYF) for I-shaped section is developed by means of regression technique with suitable collocation points. The order of the polynomial expression is determined for the HGYF by error analysis. Based on the HGYF,the element bearing ratio( EBR) is defined. The uniformity of EBR and reference EBR are determined by statistical parameters of EBR. An adaptive modulus adjustment strategy is developed based on the principle of conservation of deformation energy and the dynamic criterion for identification of highly stressed elements. Therefore,the elastic modulus reduction method is presented for load bearing capacity of thin-walled structures with I-shaped section.Numerical examples show that the method presented can achieve higher accuracy and efficiency,compared with traditional elastic modulus adjustment procedures.
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2015年第5期902-913,共12页
Journal of Basic Science and Engineering
基金
国家自然科学基金项目(51168003
51169003)
广西自治区主席科技资金项目(2010GXNSFD169008)
广西自然科学基金重大项目(2012GXNSFEA053002)
关键词
齐次
广义屈服函数
工字型截面
极限承载力
弹性模量缩减法
homogeneous
generalized yield function
I-shaped section
loading bearing capacity
elastic modulus reduction method
