平面应变断裂韧性<i>K</i><sub>1c</sub>不确定度评定

平面应变断裂韧性K_1c不确定度评定

摘要: 依据JJF 1059.1—2012中的GUM法对7075-T651铝合金断裂韧性K_1c进行不确定度评定。预裂纹试验条件：应力比R=0.1，频率f=20 Hz，波形为正弦波，终止裂纹长度a=25 mm。根据Shapiro-Wilk检验，断裂韧性服从正态分布。7075-T651铝合金断裂韧性K_1c试验结果可以表示为：K=25.3 MPa·m^0.5，U=0.9 MPa·m^0.5，k=2，自由度 ν_eff=10。

Abstract: According to the GUM method in JJF 1059.1—2012, the uncertainty of fracture toughness K_1c of 7075-T651 aluminum alloy was evaluated. Pre-crack test conditions: stress ratio R=0.1, frequency f=20 Hz, waveform was sine wave, termination crack length a=25 mm. According to the Shapiro-Wilk test, the fracture toughness followed a normal distribution. The fracture toughness K_1c test results of 7075-T651 aluminum alloy could be expressed as K=25.3 MPa·m^0.5, U=0.9 MPa·m^0.5, k=2 and degree of freedom ν_eff=10.