本文简要叙述了测定提升机主轴断裂韧度Jc、a_k、da/dN ΔK_(th)等的重要工程意义及测试的基本原理,给出了该材料的断裂韧度以及有关的数据,对于主轴材料的L—R三点弯曲试样在压裂试验过程中,裂纹扩展量较小,且具有脆性失稳断裂的特点进行了分析,提出了按估算极限载荷来控制停机点的试验方法,并对J—K的换算提出了建议。 This article briefly describes the important engineering significance and test principle for determining the fracture toughness Jc, a_k, da / dN ΔK_ (th) of the main shaft of the hoisting machine, gives the fracture toughness of the material and the related data, The L-R three-point bending test specimen has a small crack growth rate and has the characteristics of brittle instability fracture during the fracturing test. The test method for controlling the stop point according to the estimated limit load is proposed. J-K conversion made recommendations.