Nonlinear ultrasonic characterization of fatigue microstructures
Nonlinear ultrasonic characterization of fatigue microstructures
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DOI：
10.1016/s0142-1123(01)00162-1
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发表时间：
2001-01-01
影响因子：
6
通讯作者：
Yost, WT
中科院分区：
文献类型：
--
作者：
Cantrell, JH;Yost, WT
金属疲劳过程中形成的位错偶极子子结构，产生了大量的超声波通过疲劳材料传播的失真。超声波位错偶极相互作用的模型的开发，量化的波的失真通过材料的非线性参数β。该模型的应用AA 2024-T4预测的β值约300%，在应力控制在276 MPa和R=0的100 kcycles循环加载的材料比测量的原始材料。实验测量结果表明，作为接近预测增加的疲劳周期数的函数，β单调增加。实验还表明，相关的位错亚结构是本地化的材料。出版社：Elsevier Science Ltd
Dislocation dipole substructures formed during metal fatigue are shown to produce a substantial distortion of ultrasonic waves propagating through the fatigued material. A model of ultrasonic wave-dislocation dipole interactions is developed that quantifies the wave distortion by means of a material nonlinearity parameter beta. Application of the model to AA2024-T4 predicts a value of beta approximately 300% larger in material cyclically loaded for 100 kcycles in stress-control at 276 MPa and R=0 than that measured for virgin material. Experimental measurements show a monotonic increase in beta as a function of the number of fatigue cycles that closely approaches the predicted increase. The experiments also suggest that the relevant dislocation substructures are localized in the material. Published by Elsevier Science Ltd.