载电流夹紧杆的非线性稳定性分析*
Nonlinear Stability Analysis of a Clamped Rod Carrying Electric Current
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摘要: 本文研究了载电流夹紧杆在磁场作用下的非线性稳定性,其磁场由两根无限长相互平行的刚性直导线产生.杆的自然状态在刚性导线所在的平面内,并且与两刚性导线等距.首先,在空间变形的假定下,给出了问题的数学描述,讨论了线性化问题和临界电流.其次,证明了杆的过屈曲状态总是平面的.最后,数值计算了分支解的全局响应,得到了杆过屈曲状态的挠度、内力和弯矩的分布.结果表明,载电流杆既可发生超临界屈曲,又可发生次临屈界曲,其性态依赖于杆与导线间的距离;同时,在超临界的过屈曲状态上还存在极限点型的失稳,这与通常的压杆失稳有着本质的区别.Abstract: This paper is devoted to the analysis of the nonlinear Stability of a clamped rodcarrying electric current in the magnetic field which is produced by the current frowingin a pair of inifinitely long parallel rigid wires. The natural State of the rod is in theplane of the wires and is equidistant from them.Firstly under the assumption of apatial deformation, the governing equations of the problem are derived, and the linearizedproblem and critical currents are discussed. Secondly, it ls proved that the buckledstates of the rod are always in planes. Finally. the global responses of the bifurcationproblem of the rod are compuled numerically and the distributions of the deflections.axial forces and bending monents are obtained. The results show that the buckledslates of the rod may be either supercritical or Subcritical. depending on the distancebetween the rod and the wires. Furthermore, it is found that-there exists a limit pointon the branch solution of the supercritical buckled State. This is distinctively differentfrom the buckled slate of the elastic compressive rods.
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