摘要
通过选取黄铜(Hb2)、优质结构钢(45#)、普通低合金钢(16Mng)、合金钢(Icr13)、铝合金(Lr12)五种金属材料，用不同的截面形状和加载速率对其流动极限进行试验研究。理论分析和实验结果表明：在不同的材质、加载速率和截面形状条件下，应力分布不均匀对流动极限的影响很小，并能够忽略，因此可以认为，金属材料的流动极限是一个固有的物理常数，应力分布不均匀对其几乎没有什么影响。
The effect of variation in stress gradient on the yield piont has been studied for copper, first-rate structural steel, common low alloy steel, steel alloy and aluminum alloy five kinds of metallic materials made into samples of various cross-sectional forms and subject to different loadding rates .Both theoretical analysis and test results indicate that on condiction of different quality of a material, various cross-sectional forms and subject to different loadding rate, variation stress gradient has very little effect on it and can be ignored. It may be held that the yield piont is an inherent physical constant for materials and that variation in stress gradient has almost no effect on it.
