本文采用卸载剖面法测试了CCT试件和TPB试件的卸载COD阻力曲线及卸载伸张区,并且用弹塑性有限元法计算了两种试件裂纹前方韧带上的应力应变场。试验结果表明,COD启裂值和阻力曲线斜率均依赖于试件型式。CCT试件的断裂阻力比TPB试件的断裂阻力大。两种试件边界条件不同,尖端附近应力应变场也不同,因此导致了断裂阻力的差别. In this paper, the unloading COD drag curves and unloading extension zones of CCT and TPB specimens were tested by unloading profile method. The stress and strain fields on the anterior ligaments of both specimens were calculated by the elasto-plastic finite element method. The test results show that both the COD cracking resistance and the slope of the resistance curve depend on the specimen type. The fracture resistance of the CCT specimen is greater than the fracture resistance of the TPB specimen. The boundary conditions of the two specimens are different, and the stress and strain fields near the tip are also different, which leads to the difference of fracture resistance.