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进行了国产２０２４－Ｔ３５１铝合金在单峰过载条件下试样厚度对疲劳裂纹扩展性能影响的试验和分析研究。结果表明：试样厚度对裂纹扩展迟滞有明显的影响；Ｊ．Ｂ．Ｃｈａｎｇ模型中的过载截止比不是材料常数，它还和疲劳裂纹扩展的应力状态、载荷序列及试样厚度等因素有关。厚试样有较大的过载截止比，用Ｊ．Ｂ．Ｃｈａｎｇ模型进行疲劳裂纹扩展寿命预测时应采用相应试样厚度的过载截止比。
The experimental and analytical studies on the influence of specimen thickness on the fatigue crack propagation properties of domestic 2024-T351 aluminum alloy under unimodal overloading conditions were carried out. The results show that the thickness of specimen has a significant influence on the crack propagation retardation. B. The overload cut-off ratio in the Chang model is not a material constant. It is also related to the stress state of the fatigue crack growth, the load sequence and the thickness of the specimen. Thick samples have a larger overload cut-off ratio, using J. B. Chang model fatigue crack growth life expectancy should be used for the corresponding sample thickness overload cut-off ratio.