摘要
本文由变分法中的最小势能原理导出两端铰支的梁柱屈曲时的最小轴向压力，并用总位能的二阶变分说明这个最小轴向压力就是该梁柱的临界压力Ｐｃｒ。
in this paper, by adopting the variation calculus on the basis of the principle of minimum potential energy, the minimum axial compression force is obtained and, by using the second-order variation of the total potential energy, the minimum axial force is proved to be the critical pressure for the beam column to lose stability.
关键词
屈曲
临界压力
梁柱
变分法
铰支座
稳定性
buckling
stable equilibrium
variation
positive definite quality
critical pressure
