王成立¹，李双蓓²
(1 广西华蓝设计集团有限公司，南宁530011; 2 广西大学土木建筑工程学院，南宁530004)

[摘要] 针对现有杆系结构考虑初始缺陷的方法存在不同程度的缺点和不足，在普通梁单元中引入两种合理的初始几何缺陷函数，导出两种改进的考虑初始几何缺陷的非线性梁单元，同时考虑了二阶效应及初始几何缺陷的影响，在此基础上利用MATLAB编写了有限元程序。通过算例分析表明本文改进的几何缺陷非线性梁单元效率高，可操作性强。
[关键字] 非线性梁单元；初始几何缺陷；缺陷函数；二阶效应

Two improved nonlinear beam elements considering initial geometry imperfechon
Wang Chengli¹, Li ShuangbeI²
(1GuanGXi Hualan Design & consulting Group, Nanning 530011, China; 2 Department of Civil Engineering Guangxi University, Nanning 530004, China)

Abstract: According to the shortcoming of the analysis method in lattice structures that consider intial defect, two reasonable initial geometry defect functions are added in beam element as well as two improved nonlinear beam elements which considering initial geometry defect is derived. The two analysis methods have taken into account the effect of second-order effect and initial geometry defect. Then compile finite element programs with Matlab. The numerical results show that the improved nonlinear beam elements not only high-efficiency but also easily handing.
Keywords: nonlinearity beam element;  intial geometry defection;  defect function:  second-order effect