Based on energy theory, a simple critical force calculation for pressed beam with variable cross sections is derived. It reduces the complex integration algorithm into a simple algebraic operation.
以能量原理为基础，推导出变截面压杆计算临界力的简便方法，把复杂的积分运算归结为一个简单的代数运算。
2
Under certain condition it is proved that all the complex eigenvalues of this operator, except at most finitely many ones, are of algebraic multiplicity 1.
在一定的条件下证明了，除至多有限个外，人口算子复本征值的代数重数均为1。
3
The method is straight-forward and efficient, since it reduces the nonstationary response problem to complexalgebraic operations only.