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在两组试验上进行低强度高韧性合金钢的三点弯曲试样屈服后断裂力学分析。第一组试验,试样尺寸固定,裂纹长度变化。第二组试验为几何形状类似的亚标准试样。试验的最小试样尺寸为有效尺寸的八分之一。用三种屈服后理伦J积分,Bilby,Cottrell和Swinden(BCS)方法以及Witt的等价能量法分析试验结果。在观察到的实验离散性范围内,用J积分、BCS法或者标准的线弹性断裂力学理论详细描述短裂纹长度试样的结果。在有效实验的离散带内,用Witt的等价能量法预测几何形状相似的那组试样的韧性值很一致。用DCS法和J积分方法对试样尺寸最小的两组试样进行估算的韧性值偏低。可以用平面应变塑性约束向平面应力下的非约束的放宽来解释这种现象。仿做并重新处理了弯曲试样其他一些工作结果。
Fracture mechanics analysis of the three-point bending specimens of low strength and high toughness alloy steel after yielding was performed on two sets of tests. The first group of tests, the sample size is fixed, the crack length changes. The second group of tests is a sub-standard specimen of similar geometry. The minimum test specimen size is one eighth of the effective size. The test results were analyzed using three Yield Ricard J-scores, Bilby, Cottrell and Swinden (BCS) methods, and Witt’s equivalent energy method. Within the range of experimental discrepancies observed, the results of short crack length specimens are described in detail using the J-integral, BCS method or standard linear elastic fracture mechanics theory. In the effective experimental discrete bands, Witt’s equivalent energy method was used to predict the toughness values of the groups of similar geometries. The ductility values estimated by the DCS method and the J-integral method on the two groups of samples with the smallest sample size are lower. This phenomenon can be explained by the unconstrained relaxation of the plane strain plastic constraint to the plane stress. Imitation and reprocessing of the bent specimen some other work results.