The influence of the ratio between specimen thickness ($t$) and grain size ($D$) on the tensile and fatigue properties of plain and notched aluminium plate specimens has been studied. Grain sizes ranging from 66 $\mathrm{\mu }$m to 9.74 mm have been prepared and used in the tests. The observed decrease on tensile properties when $D$ is comparable, or even exceeds, $t$ can be accounted for by adding an additional negative exponential term to the Hall–Petch equation. An exponential decrease has also been found in endurance limits as grain size approaches plate thickness in plain specimens. In notched specimens, however, increasing grain size has two opposing effects, namely: a decrease in the plain endurance limit associated with the decrease in thickness relative to grain size and an increase in notched fatigue strengths brought about by a decrease in notch sensitivity.

试件厚度比的影响（$吨$) 和粒度 ($D$) 对普通和缺口铝板试样的拉伸和疲劳性能进行了研究。粒度范围从 66 $\mathrm{\mu }$m 至 9.74 mm 已准备好并用于测试。观察到的拉伸性能下降时$D$可比，甚至超过，$吨$可以通过在 Hall-Petch 方程中添加一个额外的负指数项来解释。随着晶粒尺寸接近普通试样的板厚，耐久性极限也呈指数下降。然而，在缺口试样中，增加晶粒尺寸有两个相反的影响，即：与晶粒尺寸相关的厚度减小相关的普通耐力极限的降低和缺口敏感性降低带来的缺口疲劳强度的增加。