预应力撑杆柱整体稳定性能的数值分析

在正确定义单元类型、实常数和边界条件等基础上，采用有限元分析软件ANSYS建立预应力撑杆柱的有限元模型，对单横隔预应力撑杆柱在平面内的对称和反对称的2种屈曲模态进行数值分析。采用有限元软件ANSYS对预应力撑杆柱和无预应力柱进行弹性屈曲分析并与已有文献的分析结果进行对比以验证有限元模型的正确性；对预应力撑杆柱进行扩展参数分析，分析预应力撑杆柱的横撑杆长度h、预应力T及横撑杆直径D_s等主要影响参数对其弹性屈曲荷载的影响。研究表明:当预应力撑杆柱发生对称屈曲时，其弹性屈曲荷载N_cr随着横撑杆长度h的增大而增大，与横撑杆直径D_s无关；当预应力撑杆柱发生反对称屈曲时，其弹性屈曲荷载N_cr随着横撑杆直径D_s的增大而增大，而横撑杆长度h对其影响较小；预应力撑杆柱的2种屈曲模态的弹性屈曲荷载N_cr随着预应力T的增大而增大，当预应力T超过某个临界最优值T_opt时，弹性屈曲荷载N_cr随着预应力T的增大而减小。

Numerical Analysis on Overall Stability Behavior of Prestressed Stayed Column

The finite element model of prestressed stayed column was established by the software of finite element analysis ANSYS, which was based on the correctdefinitions of element type, real constant and boundary conditionsin this paper. And two types of buckling modes of single-crossarmprestressed stayed columns in the plan were numerically analyzed. Firstly, the elastic buckling of prestressed stayed column and common column were analyzed by ANSYS and their results were compared with the results calculated in the literature to verify the correctness of finite element model. Then, extended parameter analysis was carried out for prestressed stayed column, and the influence of the length and diameter of single-crossarm and prestress on the elastic buckling loads was analyzed. Researches showed that when the symmetric buckling mode of prestressed stayed column occur, the elastic buckling loads Ncr increased with theincreasementof length of single-crossarm, but the diameter of single-arm had no influence on the elastic buckling loads Ncr. When the anti-symmetric buckling mode of prestressed stayed column occur, the elastic buckling loads Ncr increased with the increasement of diameter of single-crossarm, but the length of single-arm had a little influence on the elastic buckling loads Ncr. In addition, the elastic buckling loads increased with the increasement of prestress, but when the prestress reach to the optimal value T_opt, the elastic buckling load decreased with the increasement of the prestressed.