恒荷载下结构极限分析的弹性模量缩减法  

Elastic modulus reduction method for limit analysis of structures under dead load

作　　者：林银河[1,2] 杨绿峰[1,2] 周景景[1,2] 

机构地区：[1]广西大学工程防灾与结构安全教育部重点实验室 [2]广西大学土木建筑工程学院,广西南宁530004

出　　处：《广西大学学报（自然科学版）》2011年第1期45-52,共8页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(50768001);广西自然科学基金重点项目(桂科自0991020Z);广西科技计划项目(桂科能0992028-7)

摘　　要：基于塑性极限分析的基本原理,提出一种考虑恒荷载效应的结构极限承载力分析的弹性模量缩减法。利用线弹性有限元迭代计算求解活荷载的极限值,并且在每一步迭代计算中将恒荷载视为伪活荷载,并和活荷载一起按比例增加。结合能量守恒原理和广义屈服准则建立离散单元弹性模量的调整策略,提出了结构广义承载空间中的活荷载极限值的迭代求解格式。在每一步迭代计算中,通过调整高应力单元的弹性模量来模拟结构在恒荷载、活荷载联合作用下的内力重分布及其失效模式的演变过程,从而获得恒荷载效应下结构的极限承载力及其失效模式。算例分析表明弹性模量缩减法具有较高的计算效率和计算精度。Based on the theory of plastic limit analysis,an elastic modulus reduction method（EMRM） for structures considering the effect of dead load is presented.The linear elastic finite element method（FEM） and the iteration procedures are employed to obtain the limit of live loads,while the dead load is regarded as the pseudo-living load and increases proportionally with the live loads in every iteration.The ultimate live load in the generalized load space can be obtained by means of the elastic modulus adjustment based on the principle of energy conservation and the generalized yield criterion.In each iterative step,the elastic modulus of the element with high element bearing ratio is reduced so as to simulate the evolution of the failure modes and the internal forces redistribution.Therefore,the limit load of the live load can be obtained for the structures under dead load effect.Numerical examples demonstrate the effectiveness and efficiency of the proposed method.

关 键 词：弹性模量缩减法 极限承载力 恒荷载 单元承载比 能量守恒 

分 类 号：TB125[理学—工程力学]