As an example, the stability analysis of a multistepped column is discussed, and a precise recurrence formula is offered to solve the problems of critical force of any telescopic boom in crame.

• 本文以起重机箱形伸缩吊臂为例，对多节变截面阶梯柱的稳定性进行分析，给出任意阶起重机箱形伸缩臂临界力求解的精确递推公式。