本文提供了一个非常简单的TPB试样的K_1表达式,它在很宽的范围内(a/W=0.12～1.0)其精度在1%以内。作者试图说明,导致裂纹试样在弹性状态下起裂的约束主要来自试样的韧带,而不是裂纹长度。从而可以设计出使试样发生弹性断裂的最小面内尺寸。 This article provides a very simple K_1 expression for a TPB specimen that has an accuracy of within 1% over a wide range (a / W = 0.12 to 1.0). The authors attempted to show that the constraints that led to crack initiation in the cracked state of the cracked specimen mainly came from the ligaments of the specimen rather than the crack length. Thus, the minimum in-plane dimension for elastic fracture of the specimen can be designed.