局部削弱对压杆稳定性影响的研究

Buckling Analysis of the Locally Weakened Column

采用有限元方法研究局部削弱对压杆临界载荷及失效模式的影响。首先分析了含较小削弱杆件的线弹性屈曲问题,其次着重分析了含较大削弱杆件的非线性屈曲问题,给出了完整的削弱与临界载荷的关系曲线,并分析了柔度、削弱比等参数的影响。结果表明:局部削弱对线性屈曲影响不大,可忽略其影响;但对于非线性屈曲,失稳载荷显著减小,削弱不能被忽略;非线性屈曲对削弱位置相对敏感而线性屈曲受削弱位置影响不大;当削弱个数增加时,线性和非线性屈曲的临界载荷均会下降。

In this paper,the locally weakened columns′ buckling load and failure pattern were discussed with finite element method（FEM）.Firstly,the linear buckling with small weakening was analyzed and then the nonlinear buckling with large weakening was emphasized.Finally integral curves,which present the relationship between weakening and buckling load,were carried out together with discussions of some other parameters such as flexibility and the level of weakening.The results showed that the effect of weakening on the linear buckling could be ignored,while it was significant on nonlinear buckling.The critical load was obviously reduced in nonlinear buckling,hence the weakening could not be ignored.The nonlinear buckling was sensitive to the weakened location while linear buckling was little affected by the location.The buckling load kept decreasing when the number of the weakening incerased of both linear and nonlinear buckling.