对于材料力学教学中低碳钢拉伸实验的进一步分析描述

低碳钢拉伸实验是材料力学实验中的经典实验,现阶段传统材料力学实验教学中往往只是简单的描述低碳钢拉伸时试件各阶段变化的现象,缺乏针对低碳钢塑性变形时的充分描述。文章针对上述情况,利用材料科学中的部分知识,解释了低碳钢拉伸过程中屈服阶段产生波动现象的原因;分析了强化阶段与颈缩阶段试验力变化的过程;阐述了试件进入强化阶段以后,卸载并二次加载时无屈服阶段的原因。详细分析低碳钢拉伸实验各阶段的变化过程,将会对各类学生在学习材料力学实验过程中提供帮助。

Tensile test of low carbon steel is a classical experiment in mechanics of materials. At the present stage, the experi- mental teaching of traditional material mechanics is only a simple description of the change of the specimens at different stages dur- ing the tensile test of low-carbon steel. This paper, as regards the above situation, uses some knowledge of materials science to ex- plain the reason of fluctuation in the yielding stage of low carbon steel, analyzes the change of test force during the strengthening stage and necking stage, and expounds the reasons of no yielding stage after unloading and loading two times in the strengthening stage. The change process of tensile test of low carbon steel is analyzed in detail, which is helpful for students to learn mechanics experiment.